Ingegneria delle tecnologie per la salute

Fondamenti di anatomia e istologia

Lezione 4.a.b.c

aa. 2018-19

Ingegneria delle tecnologie per la salute

Fondamenti di anatomia e istologia

aa. 2018-179

Sistema locomotore • Ossa 4.a • Articolazioni 4.b • Muscoli 4.c BONES 4.a BONE TISSUE & SKELETAL SYSTEM

After this lesson, you will be able to: • List and describe the functions of bones • Describe the classes of bones • Discuss the process of bone formation and development Functions of the Skeletal System Bone (osseous tissue) = hard, dense connective tissue that forms most of the adult skeleton, the support structure of the body. Cartilage = a semi-rigid form of connective tissue, in the areas of the skeleton where bones move provides flexibility and smooth surfaces for movement. Skeletal system = body system composed of bones and cartilage and performing following functions: • supports the body • facilitates movement • protects internal organs

• produces blood cells • stores and releases minerals and fat Bone Classification 206 bones composing skeleton, divided into 5 categories based on their shapes ( distinct function) Bone Classification Bone Structure

Bone tissue differs greatly from other tissues in the body: is hard (many of its functions depend on this hardness) and also dynamic (its shape adjusts to accommodate stresses).

histology

gross anatomy Gross Anatomy of Bone structure of a LONG BONE, 2 parts: 1. diaphysis: tubular shaft that runs between the proximal and distal ends of the bone, where the hollow region is called medullary cavity (filled with yellow marrow) and the walls are composed of dense and hard compact bone 2. epiphysis: wider section at each end of the bone, filled with spongy bone (its spaces filled with red marrow epiphyseal plate (growth plate): where epiphysis meets diaphysis at the metaphysis, narrow area containing a layer of hyaline (transparent) cartilage in a growing bone (in early adulthood, appr. 18– 21 yrs, cartilage replaced by osseous tissue). Gross Anatomy of Bone endosteum = delicate membranous lining where bone growth, repair, and remodeling occur. periosteum = fibrous membrane of outer surface containing blood vessels, nerves, and lymphatic vessels that nourish compact bone and where tendons and ligaments also attach (periosteum covers the entire outer surface except where epiphyses meet other bones to form joints (covered with articular cartilage, a thin layer of cartilage that reduces friction and acts as a shock absorber). Gross Anatomy of Bone endosteum & periosteum Gross Anatomy of Bone

Flat bones = layer of diploe (spongy bone), lined on either side by a layer of compact bone, working together to protect the internal organs Gross Anatomy of Bone Gross Anatomy of Bone Bone Markings

Bony surface features vary considerably, depending on the function and location in the body  3 general classes of bone markings:

(1)articulation: where two bone surfaces come together, conforming to one another, to facilitate the function of joint (2)projection: area of a bone that projects above the surface of the bone, where are attachment points for tendons and ligaments, being an indication of the forces exerted through the attachment to the bone (3)hole: opening or groove in the bone, allowing blood vessels and nerves to enter the bone. Gross Anatomy of Bone Bone Markings Gross Anatomy of Bone

Bone Markings Bone Cells and Tissue HISTOLOGY

= a relatively small number of cells entrenched in a matrix of collagen fibers that provide a surface for inorganic salt crystals (= calcium phosphate and calcium carbonate combine to create hydroxyapatite, which incorporates other inorganic salts like magnesium hydroxide, fluoride, and sulfate as it crystallizes, or calcifies, on the collagen fibers) to adhere. • hydroxyapatite crystals = hardness and strength • collagen fibers = flexibility • cells = small amount, but crucial to the function of bones • 4 types of cells:

1. osteoblasts, 2. osteocytes, 3. osteogenic cells, 4. osteoclasts Bone Cells and Tissue HISTOLOGY

1. osteoblast = responsible for forming new bone, found in the growing portions (periosteum and endosteum), not dividing, but synthesizing collagen matrix and calcium salts, that trap them, becoming 2. osteocyte = primary cell of mature bone, located in a space called a lacuna, maintain the mineral concentration of the matrix, lacking mitotic activity and communicating with each other via long cytoplasmic processes extending in canaliculi 3. osteogenic cell = undifferentiated with high mitotic activity, found in the deep layers of the periosteum and the marrow. Bone Cells and Tissue HISTOLOGY

4: osteoclast = responsible for bone resorption, found on bone surfaces, multinucleated, originating from monocytes and macrophages Bone dynamic nature = new tissue is constantly formed (osteoblasts), and old, injured, or unnecessary bone is dissolved (osteoclasts) Bone Cells and Tissue HISTOLOGY Bone Cells and Tissue HISTOLOGY

Compact bone = denser, stronger, found under the periosteum and in the diaphyses of long bones, where it provides support and protection, being its microscopic structural unit the osteon (= concentric rings of calcified matrix called lamellae), its blood vessels, nerves, and lymphatic vessels in the central canal, or Haversian canal, + perforating canal, Volkmann’s canals, to extend to the periosteum and endosteum (osteocytes located inside lacunae, found at the borders of adjacent lamellae). Bone Cells and Tissue HISTOLOGY osteon (= concentric rings of calcified matrix called lamellae) Bone Cells and Tissue HISTOLOGY Bone Cells and Tissue HISTOLOGY Bone Cells and Tissue HISTOLOGY Bone Cells and Tissue HISTOLOGY Bone Cells and Tissue HISTOLOGY

Spongy (Cancellous) Bone contains osteocytes housed in lacunae, but arranged in a lattice-like network of matrix spikes called trabeculae (forms along lines of stress to provide strength to the bone), not in concentric circles. . Compact Bone Bone Cells and Tissue HISTOLOGY Compact bone is the . Compact Bone Bone Cells and Tissue HISTOLOGY Compact bone is the Bone Cells and Tissue HISTOLOGY

Blood and Nerve supply The spongy bone and medullary cavity receive nourishment from arteries that pass through the compact bone = nutrient foramen (small openings in the diaphysis). The osteocytes in spongy bone are nourished by blood vessels of the periosteum that penetrate spongy bone and blood that circulates in the marrow cavities. As the blood passes through the marrow cavities, it is collected by veins, which then pass out of the bone through the foramina. In addition to the blood vessels, nerves follow the same paths into the bone where they tend to concentrate in the more metabolically active regions of the bone. Skeletal System

skeletal system = all of the bones, cartilages, and ligaments of the body that support and give shape to the body. skeleton = bones of the body (adults = 206 bones), subdivided into 2 major divisions: axial (80) and appendicular (126). Skeletal System

Axial (80 bones) Appendicular (126 bones) Head Trunk UpperExtremities Lower Extremities (29 bones) (51bones) (64 bones) (62 bones)

Legs and hips (10)Innominat Cranial (8) Frontal— e or hip bone(fusion of the ili 1 Parietal—2Occipital— Arms andshoulders (10)Clavi um,ischium, and pubis)— 1Temporal—2Sphenoid— cle—2Scapula—2Humerus— 2Femur—2 Tibia—2Fibula— 1Ethmoid— Vertebrae(26)Cervical— 2Radius—2 Ulna— 2 Patella(kneecap)— 1Facial (14)Maxilla— 7Thoracic—12Lumbar— 2 Wrists (16)Scaphoid— 2 Ankles(14) Talus— 2Mandible—1Zygoma— 5 Sacrum—1Coccyx— 2Lunate—2Triquetrum— 2Calcaneus (heel bone)— 2Lacrimal—2Nasal— 1 Ribs(24) Truerib— 2Pisiform—2Trapezium— 2 Navicular—2Cuboid— 2Turbinate—2Vomer— 14False rib—6Floatingrib— 2Trapezoid—2Capitate— 2 Cuneiform,internal— 1Palatine— 4Sternum(1) 2Hamate— 2 Cuneiform,middle— 2 Hyoid(1) Auditoryossicles ( 2Hands (38)Metacarpal 10Ph 2 Cuneiform,external— 6)Malleus—2 Incus— alanx (fingerbones)—28 2 Feet (38)Metatarsal— 2 Stapes—2 10Phalanx (toe bones)—28 Skeletal System

axial skeleton = forms the vertical axis of the body, consisting of: skull, vertebral column (including the sacrum and coccyx), and the thoracic cage, formed by the ribs and sternum.

appendicular skeleton = all bones of the upper and lower limbs. Skull cranium (skull) = skeletal structure of the head, supporting face and protecting brain, subdivided into facial bones + brain case, or cranial vault

• facial bones underlie facial structures, form the nasal cavity, enclose the eyeballs, and support the teeth of the upper and lower jaws. • rounded brain case surrounds and protects the brain and houses the middle and inner ear structures

consists of 22 individual bones [21 immobile and united into a single unit + the 22nd bone, mandible (lower jaw), only moveable bone of the skull] Anterior View of Skull anterior skull = facial bones, providing bony support for eyes and structures of face (this view is dominated by the openings of the orbits and the nasal cavity; also seen the upper and lower jaws, with their respective teeth). Anterior View of Skull orbit = bony socket housing eyeball and muscles moving the eyeball or opening upper eyelid (upper margin of ant. orbit = supraorbital margin; located near the midpoint of supraorbital margin is a small opening called supraorbital foramen, providing passage of a sensory nerve to the skin of the forehead; below orbit = infraorbital foramen, being point of emergence for a sensory nerve that supplies the ant. face below orbit). Anterior View of Skull nasal cavity = divided into halves by nasal septum (upper portion formed by perpendicular plate of ethmoid bone and lower portion being vomer bone), each side of nasal cavity is triangular in shape, with a broad inf. space that narrows sup. (looking into nasal cavity, 3 bony plates projecting from each lateral wall = larger of these being inf. nasal concha, an independent bone of the skull + located just above inf. concha, middle nasal concha, which is part of ethmoid bone + third bony plate, also part of ethmoid bone, sup. nasal concha, much smaller and out of sight, above middle concha, located just lateral to perpendicular plate, in upper nasal cavity). Anterior View of Skull

conchae Anatomy of the nasal cavity demonstrated in a 13-year-old child.A coronal computed tomography scan shows middle and inferior turbinates (asterisks) and vertical lamella of the middle turbinate attached to the cribriform plate (arrow). Lateral View of Skull

= dominated by the large, rounded brain case above and upper and lower jaws with their teeth below, separating these areas being the bridge of bone called the zygomatic arch (=bony arch that spans from the area of the cheek to just above ear canal, formed by the junction of two bony processes: a short ant component, the temporal process of the zygomatic bone [cheekbone] and a longer post portion, the zygomatic process of the temporal bone) Lateral View of Skull above the level of the zygomatic arch, is a shallow space called temporal fossa; below the level of the zygomatic arch and deep to the vertical portion of the mandible is another space called the infratemporal fossa. Bones of the Brain Case

• = contains and protects the brain (interior space, almost completely occupied by the brain, called cranial cavity, bounded sup by rounded top of the skull, called calvaria (skullcap), and the lateral and posterior sides of the skull) • bones that form the top and sides of the brain case are usually referred to as the “flat” bones of the skull. Bones of the Brain Case

• floor of brain case, referred to as base of the skull = complex area varying in depth and having numerous openings for the passage of cranial nerves, blood vessels, and the spinal cord.

• inside the skull, base is subdivided into 3 large spaces, called ant cranial fossa, middle cranial fossa, and post cranial fossa (fossa = “trench or ditch”): from ant to post, the fossae increase in depth. Bones of the Brain Case brain case consists of 8 bones, including paired parietal and temporal bones, plus unpaired frontal, occipital, sphenoid, and ethmoid bones.

Parietal Bone = forms most of the upper lateral side of the skull, being paired bones, with the right and left parietal bones joining together at the top of the skull. Each parietal bone is also bounded anteriorly by the frontal bone, inferiorly by the temporal bone, and posteriorly by the occipital bone. Bones of the Brain Case

Temporal Bone • = forms lower lateral side of the skull, so named because this area of the head (the temple) is where hair typically first turns gray, indicating the passage of time. • subdivided into 4 regions: 1 flattened, upper portion is the squamous portion, 2 below this area, projecting ant is zygomatic process forming post portion of the zygomatic arch, 3 posteriorly is the mastoid portion of the temporal bone (projecting inf from this region is a large prominence, mastoid process, which serves as a muscle attachment site, can easily be felt on the side of the head just behind earlobe), 4 on the interior of the skull, the petrous portion of each temporal bone forms the prominent, diagonally oriented petrous ridge in the floor of the cranial cavity (located inside small cavities that house the structures of the middle and inner ears) Bones of the Brain Case

Important landmarks of the temporal bone: • External acoustic meatus (ear canal)—large opening on the lateral side of the skull that is associated with the ear. • Internal acoustic meatus—opening located inside the cranial cavity, on the medial side of the petrous ridge. It connects to the middle and inner ear cavities of the temporal bone. • Mandibular fossa—deep, oval-shaped depression located on the external base of the skull, just in front of the external acoustic meatus. The mandible (lower jaw) joins with the skull at this site as part of the temporomandibular joint, which allows for movements of the mandible during opening and closing of the mouth. • Articular tubercle—smooth ridge located immediately anterior to the mandibular fossa. Both the articular tubercle and mandibular fossa contribute to the temporomandibular joint, the joint that provides for movements between the temporal bone of the skull and the mandible Bones of the Brain Case

• Styloid process—Post to mandibular fossa on the external base of the skull is an elongated, downward bony projection, so named because of its resemblance to a stylus (a pen or writing tool), serving as an attachment site for several small muscles and for a ligament that supports the hyoid bone of the neck • Stylomastoid foramen—small opening located between the styloid process and mastoid process. This is the point of exit for the cranial nerve that supplies the facial muscles. • Carotid canal—The carotid canal is a zig-zag shaped tunnel, providing passage through the base of the skull for one of the major arteries that supplies the brain. Bones of the Brain Case

Frontal Bone = single bone forming the forehead: in ant midline, between eyebrows, slight depression called glabella • also forms supraorbital margin of the orbit: near the middle of this margin, supraorbital foramen (= opening providing passage for a sensory nerve to the forehead); thickened just above each supraorbital margin, forming rounded brow ridges, located just behind eyebrows and generally larger in males. • inside cranial cavity, extends posteriorly in a flattened region forming both roof of the orbit below and floor of ant cranial cavity above Bones of the Brain Case

Occipital Bone = single bone forming post. skull and post base of cranial cavity (on outside surface, at post midline, a small protrusion called external occipital protuberance, serving as an attachment site for a ligament of the posterior neck) • on the base contains large opening of the foramen magnum, which allows for passage of the spinal cord • on either side of the foramen magnum is an oval-shaped occipital condyle. These condyles form joints with the first cervical vertebra and thus support the skull on top of the vertebral column. Bones of the Brain Case

Sphenoid Bone = single, complex bone of central skull: “keystone” bone, joining with almost every other bone of the skull and forming much of the base of central skull + extending laterally to contribute to the sides Bones of the Brain Case

Sphenoid Bone • inside cranial cavity, right and lesser wings of sphenoid bone, which resemble the wings of a flying bird, form the lip of a prominent ridge that marks the boundary between the anterior and middle cranial fossae. • sella turcica (“Turkish saddle”) located at midline of middle cranial fossa: rounded depression in the floor of the sella turcica is the hypophyseal (pituitary) fossa, which houses the pea-sized pituitary (hypophyseal) gland. Bones of the Brain Case

• greater wings of sphenoid bone extend laterally to either side away from the sella turcica, where they form the anterior floor of the middle cranial fossa and best seen on the outside of lateral skull, where it forms a rectangular area immediately anterior to the squamous portion of the temporal bone. • On the inf aspect of skull, each half of the sphenoid bone forms two thin, vertically oriented bony plates: medial and lateral pterygoid plate (pterygoid = “wing-shaped”), forming posterior, lateral walls of nasal cavity and serving as attachment sites for chewing muscles that fill the infratemporal space and act on the mandible. Bones of the Brain Case

Ethmoid Bone =single, midline bone forming the roof and lateral walls of the upper nasal cavity, the upper portion of the nasal septum, and contributing to medial wall of the orbit • On the interior of the skull, also forms a portion of floor of ant cranial cavity • Within the nasal cavity, the perpendicular plate of the ethmoid bone forms the upper portion of the nasal septum. The ethmoid bone also forms the lateral walls of the upper nasal cavity. Extending from each lateral wall are the superior nasal concha and middle nasal concha, which are thin, curved projections that extend into the nasal cavity Bones of the Brain Case

• In the cranial cavity, forms a small area at the midline in the floor of the anterior cranial fossa (also forms the narrow roof of the underlying nasal cavity) consisting of two parts, the crista galli (“rooster’s comb or crest”) is a small upward bony projection located at the midline) and cribriform plates (cribrum = “sieve”, a small, flattened area with numerous small openings termed olfactory foramina, small nerve branches from the olfactory areas of the nasal cavity pass through these openings to enter the brain.) • lateral portions are located between the orbit and upper nasal cavity, and thus form the lateral nasal cavity wall and a portion of the medial orbit wall. Bones of the Brain Case

Sutures of the Skull suture = immobile joint between adjacent bones of the skull (narrow gap filled with dense, fibrous connective tissue), are not straight, but instead follow irregular, tightly twisting paths. 2 suture lines seen on the top of the skull are the coronal (running from side to side across the skull, within the coronal plane of section) and sagittal sutures (extending post from coronal suture, running along the midline at the top of the skull in the sagittal plane of section lambdoid suture extends downward and laterally to either side away from its junction with sagittal suture (named for its shape, resembling the Greek letter lambda (Λ). squamous suture, located on lateral skull, unites the squamous portion of the temporal bone with the parietal bone Pterion = small, capital-H-shaped suture line region at the intersection of four bones Facial Bones of the Skull

= 14 bones (six paired bones: maxilla, palatine, zygomatic, nasal, lacrimal, and inferior nasal conchae and two unpaired bones: vomer and mandible) forming the upper and lower jaws, the nose, nasal cavity and nasal septum, and the orbit. Maxillary Bone = (maxilla, plural = maxillae), form the upper jaw, much of the hard palate, the medial floor of the orbit, and the lateral base of the nose. The curved, inferior margin of the maxillary bone that forms the upper jaw and contains the upper teeth is the alveolar process of the maxilla. On the anterior maxilla, just below the orbit, is the infraorbital foramen. This is the point of exit for a sensory nerve that supplies the nose, upper lip, and anterior cheek. On the inferior skull, the palatine process from each maxillary bone can be seen joining together at the midline to form the anterior three-quarters of the hard palate. The hard palate is the bony plate that forms the roof of the mouth and floor of the nasal cavity, separating the oral and nasal cavities. Facial Bones of the Skull

Palatine Bone = pair of irregularly shaped bones, contributing to the lateral walls of the nasal cavity and the medial wall of each orbit and the hard palate. Zygomatic Bone = paired, forming much of the lateral wall of orbit and lateral- inferior margins of ant orbital opening Nasal Bone = two small bones that articulate (join) with each other to form the bony base (bridge) of the nose, also supporting cartilages of the nose Lacrimal Bone = small, rectangular bone, forming the ant., medial wall of the orbit, forming a shallow depression called the lacrimal fossa Inferior Nasal Conchae = curved bony plate that projects into the nasal cavity space from the lower lateral wall Vomer Bone = unpaired triangular-shaped, forming posterior-inferior part of nasal septum Facial Bones of the Skull

Mandible = lower jaw and only moveable bone of the skull. Each side of the mandible consists of a horizontal body and posteriorly, a vertically oriented ramus of the mandible (ramus = “branch”). The ramus on each side of the mandible has 2 upward-going bony projections. The more ant projection is the flattened coronoid process of the mandible, which provides attachment for one of the biting muscles. The post projection is the condylar process of the mandible, which is topped by the oval- shaped condyle, that articulates (joins) with the mandibular fossa and articular tubercle of the temporal bone. The broad U-shaped curve located between the coronoid and condylar processes is the mandibular notch. Facial Bones of the Skull landmarks for the mandible: • Alveolar process of the mandible = upper border of the mandibular body, serving to anchor lower teeth. • Mental protuberance = forward projection from the inf margin of the ant mandible that forms the chin (mental = “chin”). • Mental foramen = opening located on each side of the ant-lat mandible, which is exit site for a sensory nerve that supplies the chin. • Mylohyoid line = bony ridge extending along the inner aspect of the mandibular body. The muscle that forms the floor of the oral cavity attaches to the mylohyoid lines on both sides of the mandible. • Mandibular foramen = opening located on the medial side of the ramus of the mandible, leading into a tunnel that runs down the length of the mandibular body. The sensory nerve and blood vessels that supply the lower teeth enter the mandibular foramen and then follow this tunnel. • Lingula = located immediately next to the mandibular foramen, on the medial side of the ramus. Orbit Nasal Septum Cranial Fossae Hyoid Bone = independent bone that does not contact any other bone and thus is not part of the skull. • It is a small U-shaped bone located in the upper neck near the level of the inf mandible, with the tips of the “U” pointing post. • serves as the base for the tongue above, and is attached to the larynx below and the pharynx post. • is held in position by a series of small muscles that attach to it either from above or below. Vertebral Column

VC, also known as spinal column or spine = consists of a sequence of vertebrae (singular = vertebra), each of which is separated and united by an intervertebral disc.

vertebrae + intervertebral discs = VC [flexible column supporting head, neck, and body, allowing for their movements & also protecting spinal cord, which passes down the back through openings in the vertebrae] Regions of VC • VC originally develops as a series of 33 vertebrae, but this number is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. • subdivided into 5 regions [vertebrae in each area named for that region and numbered in descending order]: in the neck, 7 cervical vertebrae [designated with the letter “C” followed by its number; sup C1 vertebra articulates (forms a joint) with the occipital condyles of the skull, inf C1 articulates with the C2 vertebra, and so on] + 12 thoracic vertebrae [T1–T12] + 5 lumbar vertebrae [L1–L5] + single sacrum [also part of the pelvis & formed by the fusion of 5 sacral vertebrae] + • sacral and coccygeal fusions do coccyx [tailbone, resulting from the not start until age 20 and are not fusion of 4 small coccygeal completed until middle age. vertebrae]. Curvatures of VC

 adult VC does not form a straight line, but instead has 4 curvatures along its length, to increase VC’s strength, flexibility, and ability to absorb shock [when load on the spine is increased, by carrying a heavy backpack for example, curvatures increase in depth (become more curved) to accommodate the extra weight; they then spring back when the weight is removed]  4 adult curvatures are classified as either primary or secondary curvatures: primary curves are retained from the original fetal curvature, while secondary curvatures develop after birth. Curvatures of VC

During fetal development, body is flexed ant into fetal position, giving entire VC a single curvature that is concave ant. In the adult, this fetal curvature is retained in 2 regions of the VC, as thoracic curve, which involves thoracic vertebrae, and sacrococcygeal curve, formed by sacrum and coccyx. Each of these is thus called a primary curve because they are retained from original fetal curvature of VC. secondary curve develops gradually after birth as the child learns to sit upright, stand, and walk. Secondary curves are concave post, opposite in direction to the original fetal curvature: cervical curve of the neck region develops as the infant begins to hold their head upright when sitting & later, as the child begins to stand and then to walk, lumbar curve of lower back develops.

In adults, the lumbar curve is generally deeper in females. General Structure of a Vertebra

Within the different regions of the VC, vertebrae vary in size and shape, but they all follow a similar structural pattern. A typical vertebra will consist of: 1. body 2. vertebral arch 3. 7 processes General Structure of a Vertebra

1. body is the ant portion of each vertebra, supporting the body weight, so progressively increase in size and thickness going down the VC: bodies of adjacent vertebrae are separated and strongly united by an intervertebral disc. 2. vertebral arch forms the post portion of each vertebra, consisting of 4 parts, right and left pedicles + right and left laminae. Each pedicle forms one of the lateral sides of the vertebral arch and are anchored to the post side of the vertebral body. Each lamina forms part of the post roof of the vertebral arch. General Structure of a Vertebra

The large opening between the vertebral arch and body is the vertebral foramen, which contains the spinal cord. In the intact vertebral column, the vertebral foramina of all of the vertebrae align to form the vertebral (spinal) canal, which serves as the bony protection and passageway for the spinal cord down the back. When the vertebrae are aligned together in the vertebral column, notches in the margins of the pedicles of adjacent vertebrae together form an intervertebral foramen, the opening through which a spinal nerve exits from the vertebral column General Structure of a Vertebra

7 processes arise from vertebral arch. (2) each paired transverse process projects laterally and arises from the junction point between the pedicle and lamina. (1) single spinous process (vertebral spine) projects post at the midline of the back. transverse and spinous processes serve as important muscle attachment sites (2) sup articular process extends or faces upward (2) inf articular process faces or projects downward paired sup articular processes of one vertebra join with the corresponding paired inf articular processes from the next higher vertebra. These junctions form slightly moveable joints between the adjacent vertebrae. The shape and orientation of the articular processes vary in different regions of the VC and play a major role in determining type and range of motion available in each region. General Structure of a Vertebra bodies of adjacent vertebrae are separated and united by an intervertebral disc, which provides padding and allows for movements between adjacent vertebrae. disc consists of a fibrous outer layer called the anulus fibrosus and a gel-like center called the nucleus pulposus. The intervertebral foramen is the opening formed between adjacent vertebrae for the exit of a spinal nerve. Regional Modifications of Vertebrae

In addition to the general characteristics of a typical vertebra described above, vertebrae also display characteristic size and structural features that vary between the different vertebral column regions. Thus, cervical vertebrae are smaller than lumbar vertebrae due to differences in the proportion of body weight that each supports. Thoracic vertebrae have sites for rib attachment, and the vertebrae that give rise to the sacrum and coccyx have fused together into single bones. Cervical Vertebrae

Typical C vertebrae, such as C4 or C5, have several characteristic features that differentiate them from T or L vertebrae: a small body [reflecting the fact that they carry the least amount of body weight], a bifid (Y-shaped) spinous process [spinous processes of C3–C6 are short, but C7 is much longer], transverse processes sharply curved (U-shaped) to allow for passage of the cervical spinal nerves] and also having an opening called transverse foramen [important artery that supplies brain ascends up the neck by passing through these openings], sup and inf articular processes flattened and largely face upward or downward, respectively. Cervical Vertebrae first and second C vertebrae further modified, giving each a distinctive appearance: C1 also called atlas, supporting skull on top of VC (in Greek mythology, Atlas was the god who supported the heavens on his shoulders), does not have a body or spinous process, instead, being ring-shaped, consisting of an ant arch and a post arch, transverse processes longer and extending more laterally than do the transverse processes of any other C vertebrae; sup articular processes face upward and deeply curved for articulation with the occipital condyles on the base of the skull; inf articular processes flat and facing downward to join with the sup articular processes of C2. Cervical Vertebrae

C2 called axis, serving as axis for rotation when turning head toward right or left, resembling typical C vertebrae in most respects, but easily distinguished by dens (odontoid process = bony projection extending upward from vertebral body and joining with inner aspect of ant arch of atlas, where is held in place by transverse ligament) Thoracic Vertebrae bodies of T vertebrae are larger than C: characteristic feature for a typical midT is spinous process, long with a pronounced downward angle causing to overlap the next inf vertebra; sup articular processes of thoracic vertebrae face ant and inf post; additional articulation sites, each called a facet, where rib attached [= 2 facets located on lat sides of body, called costal facet (costal = “rib”),being for articulation with the head (end) of a rib + additional facet located on transverse process for articulation with tubercle of a rib]. Lumbar Vertebrae

L vertebrae carry greatest amount of body weight and are thus characterized by the large size and thickness of vertebral body: short transverse processes and a short, blunt spinous process that projects posteriorly; articular processes are large, with the sup facing backward and the inf facing forward. Sacrum and Coccyx sacrum = triangular-shaped bone, thick and wide across its sup base where it is weight bearing and then tapers down to an inf, non-weight bearing apex, formed by fusion of 5 S vertebrae [process beginning after age of 20, on ant surface lines of vertebral fusion can be seen as 4 transverse ridges; on post surface, running down the midline, median sacral crest, a bumpy ridge = remnant of the fused spinous processes; similarly, fused transverse processes form lateral sacral crest]; sacral promontory = ant lip of sup base of sacrum and lateral to this a roughened auricular surface, which joins with ilium portion of hipbone to form the immobile sacroiliac joints of the pelvis. Sacrum and Coccyx

Passing inf through sacrum is a bony tunnel called sacral canal, which terminates at the sacral hiatus near the inf tip of S; ant and post surfaces have a series of paired openings called sacral foramina (singular = foramen) that connect to the sacral canal. Each of these openings is called a post (dorsal) sacral foramen or ant (ventral) sacral foramen. These openings allow for the ant and post branches of sacral spinal nerves to exit sacrum; sup articular process of sacrum, one of which is found on either side of the sup opening of sacral canal, articulates with the inf articular processes from the L5.

coccyx, or tailbone, = derived from fusion of 4 very small coccygeal vertebrae, articulates with inf tip of sacrum, not weight bearing in standing position, but may receive some body weight when sitting. Intervertebral Discs and Ligaments of the VC

 bodies of adjacent vertebrae strongly anchored to each other by an intervertebral disc [= structure providing padding between bones during weight bearing, and because it can change shape, also allowing for movement between vertebrae]  Although total amount of movement available between any 2 adjacent vertebrae is small, when these movements summed together along entire length of VC, large body movements can be produced].  Ligaments that extend along the length of the VC also contribute to its overall support and stability. Intervertebral Discs

 ID = fibrocartilaginous pad filling the gap between adjacent vertebral bodies , anchored to the bodies of its adjacent vertebrae, thus strongly uniting them and also providing padding between vertebrae during weight bearing. Because of this, ID thin in the C region and thickest in the L region, which carries the most body weight: in total, IDs account for approximately 25% of body height between top of pelvis and base of the skull; are also flexible and can change shape to allow for movements of the VC.  each ID consists of 2 parts: 1 anulus fibrosus is the tough, fibrous outer layer of the disc, forming a circle (anulus = “ring” or “circle”) firmly anchored to the outer margins of the adjacent vertebral bodies; 2 inside nucleus pulposus, consisting of a softer, more gel-like material, with a high water content serving to resist compression and thus being important for weight bearing: with increasing age, the water content of the nucleus pulposus gradually declines, causing disc to become thinner, decreasing total body height somewhat, and reduces the flexibility and range of motion of the disc, making bending more difficult. Intervertebral Discs gel-like nature of the nucleus pulposus also allows the ID to change shape as one vertebra rocks side to side or forward and back in relation to its neighbors during movements of VC. Thus, bending forward causes compression of ant. portion of the disc but expansion of the posterior disc. If the posterior anulus fibrosus is weakened due to injury or increasing age, the pressure exerted on the disc when bending forward and lifting a heavy object can cause the nucleus pulposus to protrude posteriorly through the anulus fibrosus, resulting in a herniated disc (“ruptured” or “slipped” disc) and compression of a spinal nerve, resulting in pain and/or muscle weakness in the body regions supplied by that nerve. Thoracic cage (rib cage)

= thorax (chest) portion of the body, 12 pairs of ribs (anchored posteriorly to 12 thoracic vertebrae, T1–T12) with their costal cartilages and sternum, protecting heart and lungs. Sternum

3 parts: manubrium, body, xiphoid process. jugular (suprasternal) notch =shallow, U- shaped border at the top of the manubrium + clavicular notch = shallow depression located on either side at the superior-lateral margins of the manubrium; first ribs also attach to the manubrium. Ribs 2–7 attach to the sternal body. Ribs

= 12 pairs of curved, flattened bone that contributes to the wall of the thorax, articulating posteriorly with the T1–T12 thoracic vertebrae, and most attach ant via their costal cartilages to the sternum. Pectoral Girdle

appendicular skeleton = all of the limb bones + bones that unite each limb with the axial skeleton

pectoral girdle (shoulder girdle) = bones that attach each upper limb to the axial skeleton = 2 bones, scapula and clavicle. Pectoral Girdle  scapula (shoulder blade) lies on post aspect of shoulder, supported by clavicle, which also articulates with the humerus (arm bone) to form shoulder joint, being a flat, triangular-shaped bone with a prominent ridge running across its posterior surface. This ridge extends out laterally, where it forms the bony tip of the shoulder and joins with lateral end of clavicle  clavicle and scapula move together as a unit: both serve as important attachment sites for muscles that aid with movements of the shoulder and arm; right and left pectoral girdles are not joined to each other, allowing each to operate independently.  clavicle of each pectoral girdle is anchored to the axial skeleton by a single, highly mobile joint, allowing for the extensive mobility of the entire pectoral girdle, which in turn enhances movements of shoulder and upper limb. Pectoral Girdle Bones of the Upper Limb

• upper limb divided into 3 regions: arm, located between shoulder and elbow joints; forearm, between elbow and wrist joints; hand, distal to the wrist. • 30 bones in each upper limb: humerus = single bone of the upper arm + ulna (medially) and radius (laterally) = paired bones of forearm + base of the hand contains 8 bones, each called a carpal bone, + palm of the hand is formed by 5 bones, each called a metacarpal bone + fingers and thumb contain a total of 14 bones, each of which is a phalanx bone of the hand. Humerus Ulna + Radius Carpal Bones, Metacarpal Bones, Phalanx Bones Carpal Bones, Metacarpal Bones, Phalanx Bones Carpal Tunnel The Pelvic Girdle and Pelvis pelvic girdle (hip girdle) = single bone, the hip bone or coxal bone (coxal = “hip”), which serves as the attachment point for each lower limb. Each hip bone, in turn, is firmly joined to the axial skeleton via its attachment to the sacrum of the vertebral column. The right and left hip bones also converge anteriorly to attach to each other. pelvis = entire structure formed by the two hip bones, the sacrum, and, attached inferiorly to the sacrum, the coccyx The Pelvic Girdle and Pelvis Hip Bone Hip Bone Pelvis Pelvis Bones of the Lower Limb  divided into 3 regions: thigh is that portion of the lower limb located between hip joint and knee joint; leg is specifically the region between knee joint and ankle joint. Distal to the ankle is the foot. The lower limb contains 30 bones: femur, patella, tibia, fibula, tarsal bones, metatarsal bones, and phalanges

 femur single bone of the thigh + patella is the kneecap and articulates with the distal femur + tibia is the larger, weight-bearing bone located on the medial side of the leg + fibula is the thin bone of the lateral leg. + 7 tarsal bone (post portion of the foot ) + 5 metatarsal bone (mid-foot elongated bones) + 14 small bones of toes Femur + Patella Tibia + Fibula Tarsal + Metatarsal bones + Phalanges

[email protected] [email protected] JOINTS 4.b JOINTS (articulations)

each of 206 bones (only exception of the hyoid bone in the neck) connected to at least one other joints = location where bones come together: 1) some joints allow for movement between bones (=articulating surfaces of the adjacent bones can move smoothly against each other, but are the least stable), 2) others designed for stability and providing for little or no movement (joined by connective tissue or cartilage). Classification of Joints

Functional = describe Structural = take into the degree of movement account whether the adjacent available between the bones, bones are strongly anchored to ranging from immobile, to each other by fibrous slightly mobile, to freely connective tissue or cartilage, moveable joints, related to the or whether the adjacent bones functional requirements for that articulate with each other joint ( immobile or slightly within a fluid-filled space called moveable joints serve to protect a joint cavity. internal organs, give stability to the body, and allow for limited body movement, but freely moveable joints allow for much more extensive movements of body and limbs). Structural Classification of Joints

based on whether the articulating surfaces of the adjacent bones are directly connected by fibrous connective tissue or cartilage, or whether the articulating surfaces contact each other within a fluidfilled joint cavity.

3 in structural classifications:

1. fibrous joint = adjacent bones united by fibrous connective tissue. 2. cartilaginous joint = bones joined by hyaline cartilage or fibrocartilage. 3. synovial joint = articulating surfaces not directly connected, but instead come into contact with each other within a joint cavity that is filled with a lubricating fluid, allowing for free movement between the bones (most common joints of the body). Structural Classification of Joints Structural Classification of Joints Structural Classification of Joints Structural Classification of Joints Functional Classification of Joints determined by the amount of mobility found between the adjacent bones:

1. synarthrosis = immobile fibrous joints

2. amphiarthrosis = slightly moveable cartilaginous joints

3. diarthrosis = freely moveable synovial joints

Structural Classification of Joints Functional Classification of Joints 



 1. Synarthrosis (functional)

= immobile nature of these joints provide for a strong union between articulating bones. This is important at locations where bones provide protection for internal organs: sutures (fibrous joints between bones of the skull that surround and protect the brain) and the manubriosternal joint (cartilaginous joint that unites manubrium and body of the sternum for heart protection). 2. Amphiarthrosis (functional)

= joint that has limited mobility: 1. cartilaginous joint that unites bodies of adjacent vertebrae 2. pubic symphysis of the pelvis. 3. Diarthrosis (functional)

= freely mobile joint (include all synovial joints of the body, which provide the majority of body movements), most of them are found in the appendicular skeleton, thus giving the limbs a wide range of motion. divided into 3 categories, based on number of axes of motion 1. uniaxial joint only allows for a motion in a single plane (around a single axis): elbow joint 2. biaxial joint allows for motions within two planes: metacarpophalangeal 3. multiaxial joint (polyaxial or triaxial joint allows for the several directions of movement: shoulder and hip joints a. Fibrous Joints (structural)

= adjacent bones directly connected to each other by fibrous connective tissue (thus bones do not have a joint cavity between them) with a gap between bones narrow or wide. 3 types: 1. suture = narrow fibrous joint found between most bones of the skull 2. syndesmosis = bones more widely separated but held together by a narrow band of fibrous connective tissue called a ligament or a wide sheet of connective tissue called an interosseous membrane (between shaft regions of the long bones in the forearm and in the leg) 3. gomphosis = narrow fibrous joint between the roots of a tooth and the bony socket in the jaw into which the tooth fits. a1. Suture

= all joints of bones of the skull, except for the mandible, are joined to each other by a fibrous joint called a suture. The fibrous connective tissue found at a suture (“to bind or sew”) strongly unites the adjacent skull bones and thus helps to protect the brain and form the face. In adults, the skull bones are closely opposed and fibrous connective tissue fills the narrow gap between the bones. The suture is frequently convoluted, forming a tight union that prevents most movement between the bones. (functionally classified as a synarthrosis, although some sutures may allow for slight movements between the cranial bones). a2. Syndesmosis

= type of fibrous joint in which 2 parallel bones are united to each other by fibrous connective tissue: gap between bones may be narrow, with bones joined by ligaments, or wide and filled in by a broad sheet of connective tissue called an interosseous membrane. The syndesmoses found in the forearm and leg serve to unite parallel bones and prevent their separation: however, a syndesmosis does not prevent all movement between bones, and thus this type of fibrous joint is functionally classified as an amphiarthrosis.

a3. Gomphosis = specialized fibrous joint that anchors the root of a tooth into its bony socket within maxillary (upper jaw) or mandible bone (lower jaw), also known as a peg- and-socket joint. Spanning between bony walls of socket and root of tooth are numerous short bands of dense connective tissue, each of which is called a periodontal ligament. Due to immobility gomphosis is functionally classified as a synarthrosis. a1. Suture Fibrous Joints

a2. Syndesmosis Fibrous Joints

a3. Gomphosis b. Cartilaginous Joints (structural)

= adjacent bones united by cartilage, a tough but flexible type of connective tissue, lacking a joint cavity

2 types of cartilaginous joints: 1. synchondrosis = bones are joined by hyaline cartilage (also places where bone is united to a cartilage structure, such as between anterior end of a rib and costal cartilage of thoracic cage) 2. symphysis = bones joined by fibrocartilage Cartilage: Characteristics

Develops from mesenchyme and consists of cells, connective tissue fibers, and ground substance Nonvascular, gets nutrients via diffusion through ground connective tissue fibers, and ground substance Performs numerous supportive functions Cells include chondrocytes and chondroblasts 3 types of cartilage: 1.hyaline 2.elastic 3.fibrocartilage Cartilage: Characteristics Cartilage: Characteristics

Perichondrium:  Found on peripheries of hyaline and elastic cartilage  Peripheral layer is dense vascular connective tissue with type I collagen  Inner layer is chondrogenic and gives rise to chondroblasts that secrete cartilage matrix  Articular hyaline cartilage of bones and fibrocartilage NOT lined by perichondrium Cartilage: Characteristics

Cartilage Matrix  Produced and maintained by chondrocytes and chondroblasts  Contains large proteoglycan aggregates and is highly hydrated (high water content)  Allows diffusion and is semirigid shock absorber  Adhesive glycoprotein chondronectin binds cells and fibrils to the surrounding matrix  Elastic cartilage provides structural support and increased flexibility Cartilage: Characteristics

Cartilage Matrix Cartilage: Characteristics Cartilage Cells  Primitive mesenchymal cells differentiate into chondroblasts that synthesize matrix  Mesenchyme also differentiates into fibroblasts of the perichondrium  Mature cartilage cells, chondrocytes, become enclosed in lacunae  Main function of chondrocytes is to maintain the cartilage matrix  Inner layer of surrounding connective tissue perichondrium is chondrogenic  Cartilage grows by both interstitial and appositional growth 1. Hyaline Cartilage Most common in the body and serves as a skeletal model for most bones In developing bones, cartilage present in epiphyseal plates for bone growth in length Replaced by bone during endochondral ossification Contains type II collagen fibrils, which are not seen in histologic sections due to reflective index that is similar to that of ground substance In adults, present on articular surfaces of bones, ends of ribs, nose, larynx, trachea, and bronchi 1. Hyaline Cartilage 1. Hyaline Cartilage 1. Hyaline Cartilage Articular Cartilage

1. Hyaline Cartilage Articular cartilage

1. Hyaline Cartilage

Articular hyaline cartilage has a complex structure formed by several different layers of cells. Its primary components are water, collagen type II and proteoglycans. In the uppermost zone (tangential zone) the chondrocytes are small and round and the collagen fibres are oriented parallel to the surface. In the deeper zone (radial) the chondrocytes are larger and arranged in vertical columns and the collagen fibres also have more vertical orientation. The deepest zone contains calcified cartilage which separate hyaline cartilage from subchondral bone. Articular cartilage

1. Hyaline Cartilage 2. Elastic Cartilage

Contains branching elastic fibers in matrix and is highly flexible Found in external ear, auditory tube, epiglottis, and larynx 2. Elastic Cartilage 2. Elastic Cartilage 3. Fibrocartilage

Filled with dense bundles of type I collagen fibers that alternate with cartilage matrix Provides tensile strength, bears weight, and resists compression Found in intervertebral disks, symphysis pubis, and certain joints 3. Fibrocartilage 3. Fibrocartilage TEST in ITINERE n. 1 16.4.2019 ore 15 b. Cartilaginous Joints (structural)

= adjacent bones united by cartilage, a tough but flexible type of connective tissue, lacking a joint cavity

2 types of cartilaginous joints: 1. synchondrosis = bones are joined by hyaline cartilage (also places where bone is united to a cartilage structure, such as between anterior end of a rib and costal cartilage of thoracic cage) 2. symphysis = bones joined by fibrocartilage b1. Synchondrosis

= bones joined together by hyaline cartilage, or where bone united to hyaline cartilage; may be: a. temporary = epiphyseal plate (growth plate) of a growing long bone, ie the region of growing hyaline cartilage that unites the diaphysis (shaft) of the bone to the epiphysis (end of the bone) [bone lengthening involves growth of the epiphyseal plate cartilage and its replacement by bone: for many years during childhood growth, the rates of cartilage growth and bone formation are equal and thus the epiphyseal plate does not change in overall thickness as the bone lengthens, during the late teens and early 20s, growth of the cartilage slows and eventually stops  epiphyseal plate is then completely replaced by bone, and the diaphysis and epiphysis portions of the bone fuse together to form a single adult bone. This fusion of diaphysis and epiphysis = synostosis. Once this occurs, bone lengthening ceases.] b1. Synchondrosis b. permanent = found in the thoracic cage, like first sternocostal joint, where the first rib is anchored to the manubrium by its costal cartilage. (The articulations of the remaining costal cartilages to the sternum are all synovial joints.) Additional synchondroses are formed where the anterior end of the other 11 ribs is joined to its costal cartilage. [Unlike the temporary synchondroses of the epiphyseal plate, these permanent synchondroses retain their hyaline cartilage and thus do not ossify with age]

Due to the lack of movement between the bone and cartilage, both temporary and permanent synchondroses are functionally classified as a synarthrosis. b1. Synchondrosis (temporary) b1. Synchondrosis (definitive) b2. Symphysis = cartilaginous joint where the bones are joined by fibrocartilage (= very strong because it contains numerous bundles of thick collagen fibers, thus giving it a much greater ability to resist pulling and bending forces when compared with hyaline cartilage) giving ability to strongly unite adjacent bones, but still allowing for limited movement to occur  thus functionally classified as an amphiarthrosis. b2. Symphysis Gap separating the bones at symphysis may be narrow (pubic symphysis: the pubic portions of the right and left hip bones of the pelvis are joined together by fibrocartilage across a narrow gap, and manubriosternal joint: fibrocartilage unites the manubrium and body portions of the sternum) or wide (intervertebral symphysis between bodies of adjacent vertebrae of the vertebral column: a thick pad of fibrocartilage called an intervertebral disc strongly unites adjacent vertebrae by filling the gap between them  width of intervertebral symphysis allows for small movements between the adjacent vertebrae and provides cushioning between vertebrae) b. Cartilaginous Joints

b1

b2 c. Synovial Joints (structural)

= most common type of joint in the body with structural characteristic of presence of a joint cavity (= fluid-filled space articulating surfaces of the bones contact each other) giving ability to move smoothly against each other, allowing for increased joint mobility. Synovial Joints: Structural Features

 characterized by presence of a joint cavity (walls of this space formed by the articular capsule = fibrous connective tissue structure that is attached to each bone just outside the area of the bone’s articulating surface).  bones of the joint articulate with each other within the joint cavity: friction between bones at a synovial joint is prevented by the presence of articular cartilage, a thin layer of hyaline cartilage that covers entire articulating surface of each bone, articular cartilages of each bone are not continuous with each other, acting like a coating over bone surface, allowing articulating bones to move smoothly against each other without damaging the underlying bone tissue. Synovial Joints: Structural Features

lining inner surface of the articular capsule = thin synovial membrane with cells secreting synovial fluid (synovia = “a thick fluid”), a thick, slimy fluid providing lubrication to further reduce friction between the bones of the joint and also providing nourishment to the articular cartilage, which does not contain blood vessels. synovial joint = functionally classified as a diarthrosis. Synovial Joints: Structural Features

 outside articulating surfaces, bones connected together by ligaments (= strong bands of fibrous connective tissue, strengthing and supporting joint by anchoring bones together and preventing their separation, allowing for normal movements at a joint, but limiting range of these motions, thus preventing excessive or abnormal joint movements) classified based on their relationship to the fibrous articular capsule: 1. extrinsic = located outside of articular capsule, 2. intrinsic = fused to or incorporated into the wall of the articular capsule, 3. intracapsular ligament = located inside of articular capsule  at many synovial joints, additional support is provided by the muscles and their tendons (= dense connective tissue structure that attaches a muscle to bone) acting across the joint Synovial Joints: Structural Features

 articular disc, (generally small and oval- Additional Structures Associated shaped), or meniscus, (Larger and C- with Synovial Joints shaped) = in few synovial joints, fibrocartilage structure located between the articulating bones serving several functions (depending on the specific joint): in some places, an articular disc may act to strongly unite the bones of the joint to each other (articular discs found at the sternoclavicular joint or between the distal ends of the radius and ulna bones) at other synovial joints, provide shock absorption and cushioning between the bones (each meniscus within the knee joint), finally, an articular disc can serve to smooth the movements between the articulating bones (temporomandibular joint)  Fat pad = serving as a cushion between the bones Synovial Joints: Structural Features

Additional Structures Associated with Synovial Joints Synovial Joints: Structural Features

Additional Structures Associated with Synovial Joints Synovial Joints: Structural Features

Additional Structures Associated with Synovial Joints Synovial Joints: Structural Features

 Bursa = thin connective tissue sac filled with lubricating liquid, located outside of a synovial joint serving to prevent Additional Structures friction between bones of joint and overlying muscle tendons or skin, classified by their location: subcutaneous Associated with bursa = located between skin and underlying bone, Synovial Joints allowing skin to move smoothly over the bone (prepatellar bursa located over kneecap and olecranon bursa at the tip of the elbow), submuscular bursa = found between a muscle and an underlying bone, or between adjacent muscles, preventing rubbing of the muscle during movements (trochanteric bursa found at the lateral hip, between the greater trochanter of the femur and the overlying gluteus maximus muscle), subtendinous bursa = between a tendon and a bone (subacromial bursa that protects the tendon of shoulder muscle as it passes under the acromion of the scapula, and the suprapatellar bursa that separates the tendon of the large anterior thigh muscle from the distal femur just above the knee).  tendon sheath = similar in structure to a bursa, but smaller, a connective tissue sac that surrounds a muscle tendon at places where the tendon crosses a joint, containing lubricating fluid that allows for smooth motions of the tendon during muscle contraction and joint movements. Types of Synovial Joints subdivided based on shapes of articulating surfaces of the bones

6 types : 1. pivot, 2. hinge, 3. condyloid, 4. saddle, 5. plane, 6. ball-and socket Types of Synovial Joints perno, cerniera, condyloid, sella, piano, sfera e presa 1. Synovial Joints Types: Pivot Joint

= rounded portion of a bone is enclosed within a ring formed partially by the articulation with another bone and partially by a ligament with bone rotating within this ring. since the rotation is around a single axis, pivot joints are functionally classified as a uniaxial diarthrosis type of joint. examples: 1.atlantoaxial joint, found between the C1 (atlas) and C2 (axis) vertebrae, where upward projecting dens of the axis articulates with the inner aspect of the atlas, where it is held in place by a ligament and rotation at this joint allows to turn head from side to side. 2.proximal radioulnar joint, where head of radius is largely encircled by a ligament that holds it in place as it articulates with the radial notch of the ulna, allowing rotation of radius for forearm movements. Synovial Joints Types: Pivot Joint 2. Synovial Joints Types: Hinge Join

= convex end of one bone articulates with the concave end of the adjoining bone , allowing only for bending and straightening motions along a single axis

 thus functionally classified as uniaxial joints

 Examples: 1. elbow joint, with the articulation between the trochlea of the humerus and the trochlear notch of the ulna, 2. knee, 3. ankle, 4. interphalangeal joints between the phalanx bones of the fingers and toes. Synovial Joints Types: Hinge Join 3. Synovial Joints Types: Condyloid Joint

= (ellipsoid joint), the shallow depression at the end of one bone articulates with a rounded structure from an adjacent bone or bones  Functionally, condyloid joints are biaxial joints allowing for 2 planes of movement (one movement involves bending and straightening of fingers or anterior-posterior movements of hand + second movement is a side-to-side movement, allowing spreading fingers apart and bringing them together, or moving hand in a medial-going or lateral-going direction).  Examples: 1. knuckle (metacarpophalangeal) joints of the hand between the distal end of a metacarpal bone and the proximal phalanx bone, 2. radiocarpal joint of the wrist, between shallow depression at the distal end of the radius bone and the rounded scaphoid, lunate, and triquetrum carpal bones (articulation area has a more oval [elliptical] shape). Synovial Joints Types: Condyloid Joint 4. Synovial Joints Types: Saddle Joint

= both articulating surfaces for bones have a saddle shape, which is concave in one direction and convex in the other, allowing 2 bones to fit together like a rider sitting on a saddle

 functionally classified as biaxial joints.  Example: 1. first carpometacarpal joint, between the trapezium (a carpal bone) and the first metacarpal bone at the base of the thumb (providing thumb ability to move away from the palm of the hand along two planes, thus, the thumb can move within the same plane as the palm of the hand, or it can jut out anteriorly, perpendicular to the palm: this movement of first carpometacarpal joint is what gives humans their distinctive “opposable” thumbs 2. sternoclavicular joint Synovial Joints Types: Saddle Joint 5. Synovial Joints Types: Plane Joint

= (gliding joint) articulating surfaces of bones are flat or slightly curved and of approximately same size, allowing bones to slide against each other, with motion usually small and tightly constrained by surrounding ligaments.  based only on their shape, can allow multiple movements, including rotation, thus being functionally classified as multiaxial joint (however, not all movements available to every plane joint due to limitations placed on it by ligaments or neighboring bones, thus, depending upon specific joint, a plane joint may exhibit only a single type of movement or several movements).  examples: 1. between the carpal bones (intercarpal joints) of the wrist or tarsal bones (intertarsal joints) of the foot, 2. between clavicle and acromion of the scapula (acromioclavicular joint), 3. between the sup and inf articular processes of adjacent vertebrae (zygapophysial joints). Synovial Joints Types: Plane Joint 6. Synovial Joints Types: Ball-and-Socket Joint

= joint with greatest range of motion, because rounded head of one bone (the ball) fits into the concave articulation (the socket) of the adjacent bone

 classified functionally as multiaxial joints  Only examples: 1. hip (femur head articulates with the acetabulum of hip bone) 2. glenohumeral (shoulder) joint (humerus head articulates with glenoid cavity of scapula).  femur + humerus able to move in both A-P and medial- lateral directions and also rotate around their long axis: shallow socket of glenoid cavity allows shoulder joint an extensive range of motion, but deep socket of acetabulum (+strong supporting ligaments of hip joint) serve to constrain movements of the femur, reflecting the need for stability and weight-bearing ability at the hip. Synovial Joints Types: Ball-and-Socket Joint Types of Body Movements many types of movement that can occur at synovial joints generally paired, with one being the opposite of the other. always described in relation to anatomical position of the body [=upright stance, with upper limbs to the side of body and palms facing forward] Types of Body Movements Types of Body Movements Types of Body Movements Types of Body Movements Types of Body Movements

[email protected] [email protected] MUSCLES 4.c Muscular System Muscle Tissue: histology

 3 muscle types: 1.skeletal muscle, 2. cardiac muscle, 3. smooth muscle  All muscles show similarities and differences  All muscles composed of elongated cells called fibers  Muscle cytoplasm is sarcoplasm, and muscle cell membrane is sarcolemma  Muscle fibers contain myofibrils made of contractile proteins: actin & myosin Muscle Tissue: histology 1. Skeletal Muscle  Fibers are multinucleated cells with peripheral nuclei: multiple nuclei due to fusion of mesenchyme myoblasts during embryonic development

Each muscle fiber is composed of myofibrils and myofilaments 1. Skeletal Muscle  Actin and myosin filaments form distinct cross-striation patterns  Light I bands contain thin actin, and dark A bands contain thick myosin filaments  Dense Z line bisects I bands; between Z lines is the contractile unit, the sarcomere 1. Skeletal Muscle  Accessory proteins align and stabilize actin and myosin filaments  Titin protein anchors myosin filaments, and a-actinin binds actin filaments to Z lines  Titin centers, positions, and acts like a spring between myosin and Z lines 1. Skeletal Muscle  Muscle is surrounded by connective tissue epimysium  Muscle fascicles are surrounded by connective tissue perimysium  Each muscle fiber is surrounded by connective tissue endomysium 1. Skeletal Muscle  Voluntary muscles are under conscious control  Neuromuscular spindles are specialized stretch receptors in almost all skeletal muscles  Intrafusal fibers and nerve endings are found in spindle capsules  Stretching of muscle produces a stretch reflex and movement to shorten muscle 1. Skeletal Muscle SUMMARY  Actin and myosin filaments form distinct cross-striation patterns  Light I bands contain thin actin, and dark A bands contain thick myosin filaments  Dense Z line bisects I bands; between Z lines is the contractile unit, the sarcomere  Accessory proteins align and stabilize actin and myosin filaments  Titin protein anchors myosin filaments, and a-actinin binds actin filaments to Z lines  Titin centers, positions, and acts like a spring between myosin and Z lines  Muscle is surrounded by connective tissue epimysium  Muscle fascicles are surrounded by connective tissue perimysium  Each muscle fiber is surrounded by connective tissue endomysium  Voluntary muscles are under conscious control  Neuromuscular spindles are specialized stretch receptors in almost all skeletal muscles  Intrafusal fibers and nerve endings are found in spindle capsules  Stretching of muscle produces a stretch reflex and movement to shorten muscle 1. Skeletal Muscle 1. Skeletal Muscle 1. Skeletal Muscle 1. Skeletal Muscle: Transmission Electron Microscopy

 Light bands are I bands and are formed by thin actin filaments  I bands are crossed by dense Z lines  Between Z lines is the smallest contractile unit of muscle, the sarcomere  Dark bands are A bands and are located in the middle of sarcomere 1. Skeletal Muscle: Transmission Electron Microscopy

 A bands are formed by overlapping actin and myosin filaments  M bands in the middle of A bands represent linkage of myosin filaments  H bands on each side of M bands contain only myosin filaments  Sarcoplasmic reticulum and mitochondria surround each sarcomere 1. Skeletal Muscle 1. Skeletal Muscle 1. Skeletal Muscle: functional correlation

 Skeletal muscles are voluntary, are under conscious control, and contract only when stimulated  Motor endplates are the sites of nerve innervations and transmission of stimuli to muscle  Axon terminals of motor endplates contain vesicles with the neurotransmitter acetylcholine 1. Skeletal Muscle: functional correlation

 Action potential releases acetylcholine into synaptic cleft  Acetylcholine combines with its receptors on muscle membrane  Acetylcholinesterase neutralizes acetylcholine and prevents further contraction 1. Skeletal Muscle: functional correlation

 Before arrival of impulse, calcium is stored in sarcoplasmic reticulum  Sarcolemma invaginations into each myofiber form T tubules  Expanded terminal cisternae of sarcoplasmic reticulum and T tubules form triads  Triads are located at A–I junctions in mammalian skeletal muscles  Stimulus for muscle contraction carried by T tubules to every myofiber, myofibril, and sarcoplasmic reticulum membrane 1. Skeletal Muscle: functional correlation

 After stimulation, sarcoplasmic reticulum releases calcium ions into sarcomeres  Calcium activates the binding of actin and myosin, causing muscle contraction and shortening  After the end of stimulus, calcium is actively transported and stored in sarcoplasmic reticulum  When muscle contracts, I and H bands shorten, whereas A bands stay the same  Muscle contraction and shortening draw Z lines closer together and shorten sarcomere 1. Skeletal Muscle 1. Skeletal Muscle 2.Cardiac Muscle

 Located in heart and large vessels attached to heart  Cross-striations of actin and myosin form similar I bands, A bands, and Z lines as in skeletal muscle  Characterized by dense junctional complexes called intercalated disks that contain gap junctions 2.Cardiac Muscle

 Contain one or two central nuclei, fibers are shorter and show branching  T tubules are located at Z lines and are larger than in skeletal muscle  Sarcoplasmic reticulum is less well developed than in skeletal muscles  Mitochondria are larger and more abundant in cardiac fibers 2.Cardiac Muscle

 Gap junctions couple all fibers for rhythmic contraction and form functional syncytium  For contraction, calcium is imported from outside cell and from sarcoplasmic reticulum  Exhibit autorhythmicity and spontaneously generate stimuli  Autonomic nervous system innervates heart and influences heart rate and blood pressure 2. Cardiac Muscle 2. Cardiac Muscle 2. Cardiac Muscle 2. Cardiac Muscle 2. Cardiac Muscle 3. Smooth Muscle

• Found in hollow organs and blood vessels • Zonula adherens binds muscle cells, whereas gap junctions provide functional coupling • Contain actin and myosin filaments without cross-striation patterns • Fibers are fusiform in shape and contain single central nuclei • In intestines, muscles are arranged in concentric layers, and in blood vessels in a circular pattern 3. Smooth Muscle

• Actin and myosin filaments are present, but they do not show regular arrangement or striations • Actin and myosin form lattice network, and they insert into dense bodies in sarcoplasm and cytoplasm • Dense bodies contain a-actinin and other Z disk proteins • Sarcoplasmic reticulum is not well developed for calcium storage 3. Smooth Muscle

• Sarcolemma contains invaginations called caveolae • Caveolae may control influx of calcium into cell after stimulation • Following stimulation, calcium enters sarcoplasm from caveolae and sarcoplasmic reticulum • Calmodulin, a calcium-binding protein, stimulates actin and myosin interaction • Actin and myosin contract muscle by a sliding mechanism similar to skeletal muscle 3. Smooth Muscle

• Connection of dense bodies with adjacent cells transmits force of contraction to all cells • Exhibit spontaneous activity and maintain tonus in hollow organs • Peristaltic contractions propel contents in the organs • Gap junctions couple muscles and allow ionic communication between all fibers • Innervated by postganglionic neurons of sympathetic and parasympathetic divisions • Involuntary muscles regulated by autonomic nervous system, hormones, and stretching 3. Smooth Muscle 3. Smooth Muscle 3. Smooth Muscle 3. Smooth Muscle Muscular System

After this lecture, you will be able to: • Describe the actions and roles of agonists and antagonists • Explain the structure and organization of muscle fascicles and their role in generating force • Explain the criteria used to name skeletal muscles • Identify the skeletal muscles and their actions on the skeleton and soft tissues of the body • Identify the origins and insertions of skeletal muscles and the prime movements  system to name skeletal muscles: in some cases, muscle is named by its shape, and in other cases it is named by its location or attachments to skeleton.  understanding meaning of muscle’s name, often it will help you remember its location and/or what it does, to describe how skeletal muscles are arranged to accomplish movement, and how other muscles may assist, or be arranged on the skeleton to resist or carry out the opposite movement Interactions of Skeletal Muscles in the Body

To move the skeleton, tension created by the contraction of the fibers in most skeletal muscles is transferred to the tendons. = strong bands of dense, regular connective tissue connecting muscles to bones (bone connection  muscle called skeletal muscle).

 To pull on a bone (= to change angle at synovial joint = moving the skeleton), a skeletal muscle must also be attached to a fixed part of the skeleton  moveable end of the muscle that attaches to the bone being pulled is called the muscle’s insertion, and end of the muscle attached to a fixed (stabilized) bone is called the origin. Interactions of Skeletal Muscles in the Body

prime mover, or agonist = principal muscle involved in an action, although a number of muscles may be involved

To lift a cup, a muscle called the biceps brachii is actually the prime mover; however, because it can be assisted by the brachialis, this is called a synergist in this action

synergist can also be a fixator that stabilizes the bone that is the attachment for the prime mover’s origin. Interactions of Skeletal Muscles in the Body

Antagonist = muscle with the opposite action of the prime mover play 2 important roles in muscle function: (1) maintain body or limb position, such as holding the arm out or standing erect (2) control rapid movement

also be reversed for the opposing action Interactions of Skeletal Muscles in the Body

There are also skeletal muscles that do not pull against the skeleton for movements. • muscles that produce facial expressions. • skeletal muscles in the tongue, and the external urinary and anal sphincters that allow for voluntary regulation of urination and defecation, respectively. • diaphragm contracts and relaxes to change volume of pleural cavities but it does not move skeleton to do this. Patterns of Fascicle Organization

Skeletal muscle enclosed in connective tissue scaffolding at 3 levels: 1. each muscle fiber (cell) is covered by endomysium 2. entire muscle is covered by epimysium 3. when a group of muscle fibers is “bundled” as a unit within the whole muscle (= fascicle) by an additional covering of a connective tissue called perimysium Patterns of Fascicle Organization

Fascicle arrangement by perimysia is correlated to the force generated by a muscle; it also affects the range of motion of the muscle.

Based on fascicle arrangement’s patterns, skeletal muscles can be classified in several ways  most common fascicle arrangements Patterns of Fascicle Organization

Parallel muscles = fascicles arranged in the same direction as the long axis of the muscle (majority of skeletal muscles): 1. some parallel muscles are flat sheets that expand at the ends to make broad attachments. 2. other parallel muscles are rotund with tendons at one or both ends. 3. muscles that seem to be plump have a large mass of tissue located in the middle of the muscle, between the insertion and the origin, which is known as the central body (= belly). When a parallel muscle has a central, large belly that is spindle-shaped, meaning it tapers as it extends to its origin and insertion, it sometimes is called fusiform. Patterns of Fascicle Organization Patterns of Fascicle Organization

Circular muscles = also called sphincters (= when they relax  increase the size of the opening, and when they contract  shrink to the point of closure) Convergent muscle = widespread expansion over a sizable area, but then the fascicles come to a single, common attachment point [that could be a tendon, an aponeurosis (=flat, broad tendon), or a raphe (= very slender tendon)]. Pennate muscles (= “feathers”) blend into a tendon that runs through the central region of the muscle for its whole length. Patterns of Fascicle Organization Patterns of Fascicle Organization

Due to this design, the muscle fibers in a pennate muscle can only pull at an angle, and as a result, contracting pennate muscles do not move their tendons very far. However, because a pennate muscle generally can hold more muscle fibers within it, it can produce relatively more tension for its size. Patterns of Fascicle Organization

3 subtypes of pennate muscles:

1. unipennate muscle = fascicles are located on one side of the tendon. 2. bipennate muscle = fascicles on both sides of the tendon. 3. multipennate muscles = muscle fibers wrap around the tendon, sometimes forming individual fascicles Naming Skeletal Muscles

Greek and Latin Naming Skeletal Muscles Naming Skeletal Muscles

naming according to a number of criteria (each describing muscle in some way): • shape, • size compared to other muscles in the area, • location in the body or location of its attachments to the skeleton, • how many origins it has • action.

divided into axial (muscles of the trunk and head) and appendicular (muscles of the arms and legs) categories, reflecting bones Axial Muscles of the Head, Neck, and Back

Muscles That Create Facial Expression origins of the muscles of facial expression = on skull surface (remember, the origin of a muscle does not move)  insertions = fibers intertwined with connective tissue and the dermis of the skin, thus, when contracting, skin moves to create facial expression Axial Muscles of the Head, Neck, and Back

Muscles That Create Facial Expression • orbicularis oris = circular muscle that moves the lips • orbicularis oculi = circular muscle that closes the eye • occipitofrontalis = moves up scalp and eyebrows (frontal belly + occipital belly: muscle on the forehead [frontalis]and one on the back of the head [occipitalis], but no muscle across the top of the head, two bellies connected by a broad tendon called the epicranial aponeurosis, or galea (= “apple”) • buccinator muscle = (majority of the face ) compresses cheek (whistle, blow, and suck + contributes to chew) • corrugator supercilii = prime mover of the eyebrow • several additional small facial muscles Axial Muscles of the Head, Neck, and Back

Muscles That Move the Eyes extrinsic eye muscles = movement of the eyeball, originate outside the eye and insert onto the outer surface of the white of the eye, located inside eye socket and cannot be seen on any part of the visible eyeball Axial Muscles of the Head, Neck, and Back

Muscles That Move the Eyes Axial Muscles of the Head, Neck, and Back

Muscles That Move the Lower Jaw chewing = mastication muscles involved in chewing must be able to exert enough pressure to bite through and then chew food before it is swallowed: masseter muscle = main muscle used for chewing, assisted by temporalis muscle (retracts mandible) medial pterygoid and lateral pterygoid muscles provide assistance in chewing and moving food within the mouth. Axial Muscles of the Head, Neck, and Back

Muscles That Move the Lower Jaw Axial Muscles of the Head, Neck, and Back

Muscles That Move the Tongue mastication, deglutition tongue muscles (swallowing), and speech  intrinsic (insert into the tongue from origins within it, allow the tongue to change its shape such as, curling the tongue in a loop or flattening it) +  extrinsic (insert into the tongue from outside origins, move the whole tongue in different directions), all include the word root glossus (glossus = “tongue”), and the muscle names are derived from where the muscle originates: genioglossus (genio = “chin”) originates on mandible and allows the tongue to move downward and forward; styloglossus originates on styloid bone, and allows upward and backward motion; palatoglossus originates on the soft palate to elevate the back of the tongue; hyoglossus originates on the hyoid bone to move the tongue downward and flatten it. Axial Muscles of the Head, Neck, and Back

Muscles of the Anterior Neck assist in deglutition (swallowing) + speech by controlling the positions of the larynx and hyoid bone (= horseshoe-shaped bone functioning as a solid foundation on which tongue can move), neck muscles categorized according to their position relative to hyoid bone, suprahyoid muscles superior to it, and infrahyoid muscles located inferiorly. Axial Muscles of the Head, Neck, and Back

Muscles of the Anterior Neck • suprahyoid muscles: raise hyoid bone, floor of the mouth, and larynx during deglutition, including digastric muscle (= has anterior and posterior bellies working to elevate hyoid bone and larynx when one swallows; it also depresses the mandible), stylohyoid muscle (= moves hyoid bone posteriorly, elevating the larynx), mylohyoid muscle (lifts it and helps press the tongue to the top of the mouth), geniohyoid (depresses mandible in addition to raising and pulling the hyoid bone anteriorly)

• infrahyoid muscles (strap- like) generally depress hyoid bone and control position of the larynx: omohyoid muscle (has superior and inferior bellies, depresses hyoid bone in conjunction with thyrohyoid (also elevates the larynx’s thyroid cartilage,) and sternothyroid (depresses it to create different tones of voice) Axial Muscles of the Head, Neck, and Back

Muscles That Move the Head Axial Muscles of the Head, Neck, and Back

Muscles That Move the Head Sternocleidomastoid =major muscle that laterally flexes and rotates the head, in addition, both muscles working together are the flexors of the head (divides the neck into anterior and posterior triangles when viewed from the side) Axial Muscles of the Head, Neck, and Back

Muscles of the Posterior Neck and the Back posterior muscles of the neck = primarily concerned with head movements, like extension back muscles = stabilize and move the vertebral column (grouped according to lengths and direction of the fascicles) splenius muscles = originating at the midline, run laterally and superiorly to their insertions: splenius capitis inserts onto head region, and splenius cervicis extends onto the cervical region, extending, laterally flexing and rotating head Axial Muscles of the Head, Neck, and Back

Muscles of the Posterior Neck and the Back erector spinae group = majority of the muscle mass of the back and primary extensor of vertebral column, controlling flexion, lateral flexion, and rotation and maintaining lumbar curve; comprises: . iliocostalis (laterally placed) group: iliocostalis cervicis, associated with the cervical region; iliocostalis thoracis, associated with the thoracic region; and iliocostalis lumborum, associated with the lumbar region. . longissimus (intermediately placed) group: 3 muscles = longissimus capitis, associated with the head region; longissimus cervicis, associated with the cervical region; longissimus thoracis, associated with the thoracic region. . spinalis (medially placed) group: spinalis capitis (head region), the spinalis cervicis (cervical region), and the spinalis thoracis (thoracic region). Axial Muscles of the Head, Neck, and Back

Muscles of the Posterior Neck and the Back transversospinales muscles = from transverse processes to spinous processes of vertebrae, are named for areas of the body with which they are associated: semispinalis muscles include semispinalis capitis, semispinalis cervicis, and semispinalis thoracis. multifidus muscle of lumbar region = extend and laterally flex vertebral column. segmental muscle group = important in stabilization of vertebral column, includes interspinales and intertransversarii muscles (bringing together spinous and transverse processes of each consecutive vertebra) scalene muscles = flex, laterally flex, and rotate the head and also contribute to deep inhalation, including anterior scalene muscle (anterior to the middle scalene), middle scalene muscle (the longest, intermediate between the anterior and posterior scalenes), and posterior scalene muscle (the smallest, posterior to the middle scalene). Axial Muscles of the Abdominal Wall and Thorax muscles of vertebral column, thorax, and abdominal wall extend, flex, and stabilize different parts of the body’s trunk in order to balance body on two feet and walk upright Muscles of the Abdomen 4 pairs of abd muscles, covering ant and lat abd region and meet at ant midline = muscles of antlat abd: • external obliques, • internal obliques, • transversus abdominis • rectus abdominis Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Abdomen Axial Muscles of the Abdominal Wall and Thorax

3 flat muscles in ant-lat wall of abdomen: external oblique = closest Muscles of the Abdomen to the surface, extend inferiorly and medially, internal oblique = perpendicular to it (intermediate), extending superiorly and medially, transversus abdominis = (deep muscle) arranged transversely around the abdomen,  arrangement of 3 bands of muscles in different orientations allows various movements and rotations of trunk and also help to protect internal abdominal organs in an area where there is no bone. Axial Muscles of the Abdominal Wall and Thorax linea alba = white, fibrous band that is made Muscles of the Abdomen of bilateral rectus sheaths that join at the ant midline of the body, enclosing rectus abdominis muscles (a pair of long, linear muscles) originating at pubic crest and symphysis, and extending length of body’s trunk and segmented by three transverse bands of collagen fibers called tendinous intersections. Axial Muscles of the Abdominal Wall and Thorax

Pyramidalis Muscles Axial Muscles of the Abdominal Wall and Thorax

Pyramidalis Muscles

EPIPUBIC BONE in MARSUPIALS Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Abdomen post abd wall is formed by the lumbar vertebrae, parts of the ilia of the hip bones, psoas major and iliacus muscles, and quadratus lumborum muscle = this part of the core plays a key role in stabilizing the rest of the body and mantaining posture. Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Thorax = to facilitate breathing by changing the size of the thoracic cavity Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Thorax: Diaphragm = change in volume of thoracic cavity during breathing is due to alternate contraction and relaxation; separates the thoracic and abdominal cavities, and is dome-shaped at rest (superior surface convex, creating elevated floor of thoracic cavity, inferior surface is concave, creating curved roof of abdominal cavity. Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Thorax: Diaphragm Defecating, urination, and even childbirth involve cooperation between the diaphragm and abdominal muscles (= “Valsalva maneuver”): holding breath by a steady contraction of diaphragm with stabilization of volume and pressure of peritoneal cavity + abdominal muscles contract, pressure cannot push the diaphragm up, so it increases pressure on the intestinal tract (defecation), urinary tract (urination), or reproductive tract (childbirth). Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Thorax: Diaphragm inferior surface of pericardial sac and inferior surfaces of pleural membranes (parietal pleura) fuse onto central tendon of diaphragm: to the sides of the tendon are the skeletal muscle portions of diaphragm, which insert into tendon while having a number of origins including xiphoid process ant., inferior six ribs and their cartilages laterally, and lumbar vertebrae and 12th ribs posteriorly. Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Thorax: Diaphragm diaphragm also includes 3 openings for passage of structures between thorax and abdomen: 1. inferior vena cava through caval opening, 2. esophagus and attached nerves through esophageal hiatus, 3. aorta, thoracic duct, and azygous vein through aortic hiatus of the posterior diaphragm. Axial Muscles of the Abdominal Wall and Thorax

The Intercostal Muscles 3 sets of muscles = intercostal muscles, which span each of the intercostal spaces: principal role to assist in breathing by changing rib cage dimensions 1. 11 pairs of superficial external intercostal muscles aid in inspiration, raising rib cage, which expands it 2. 11 pairs of internal intercostal muscles, just under the externals, used for expiration because they constrict the rib cage 3. innermost intercostal muscles (deepest): act as synergists for action of internal intercostals. Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Pelvic Floor and Perineum pelvic floor = muscular sheet defining inf portion of pelvic cavity: pelvic diaphragm, spanning ant to post from pubis to coccyx, comprises : levator ani [= openings consists of 2 muscles, pubococcygeus and iliococcygeus, considered the most include anal important muscle of pelvic floor supporting pelvic viscera and resisting pressure canal and produced by contraction of abd muscles applied to colon to aid in defecation and to uterus to aid in childbirth, also creates skeletal muscle sphincters at the urethra, and urethra and anus]+ assisted by the ischiococcygeus, which pulls the coccyx vagina in anteriorly women. Axial Muscles of the Abdominal Wall and Thorax

Muscles of the Pelvic Floor and Perineum perineum = diamond-shaped space between pubic symphysis (ant), coccyx (post), and ischial tuberosities (lat): divided transversely into triangles, ant urogenital triangle = external genitals and post anal triangle = anus Muscles of the Pectoral Girdle and Upper Limbs

Generality Muscles of the shoulder and upper limb can be divided into 4 groups: 1. muscles that stabilize and position pectoral girdle, 2. muscles that move arm, 3. muscles that move forearm, 4. muscles that move wrists, hands, and fingers. pectoral girdle, or shoulder girdle = consists of lateral ends of clavicle and scapula, along with proximal end of humerus, and muscles covering these 3 bones to stabilize shoulder joint. The girdle creates a base from which head of humerus, in its ball-and-socket joint with the glenoid fossa of scapula, can move arm in multiple directions. Muscles of the Pectoral Girdle and Upper Limbs

1. Muscles That Position the Pectoral Girdle located either on ant or on post thorax: anterior muscles 1. subclavius, 2. pectoralis minor 3. serratus anterior posterior muscles 1. trapezius 2. rhomboid major 3. rhomboid minor Muscles of the Pectoral Girdle and Upper Limbs

1. Muscles That Position the Pectoral Girdle Muscles of the Pectoral Girdle and Upper Limbs

= axial and scapular 2. Muscles That Move the Humerus muscles:  2 axial muscles 1. pectoralis major = thick and fan-shaped, covering much of sup portion of ant thorax. 2. latissimus dorsi = broad, triangular latissimus dorsi is located on inferior part of back, where it inserts into a thick connective tissue shealth called an aponeurosis. Muscles of the Pectoral Girdle and Upper Limbs

= axial and scapular 2. Muscles That Move the Humerus muscles:  7 muscles originating on scapula 1. deltoid = thick muscle creating rounded lines of shoulder: major abductor of arm (also facilitates flexing and medial rotation, as well as extension and lateral rotation) 2. Subscapularis = originates on ant scapula and medially rotates arm. 3. supraspinatus = (sup to the spine of the scapula) abduct the arm 4. infraspinatus = (inf to the spine of the scapula) laterally rotate the arm 5. teres major = thick and flat is inf to the teres minor and extends the arm, and assists in adduction and medial rotation of it 6. teres minor = laterally rotates and extends the arm 7. coracobrachialis = flexes and adducts the arm. Muscles of the Pectoral Girdle and Upper Limbs

= axial and scapular 2. Muscles That Move the Humerus muscles:  rotator cuff (musculotendinous cuff) = circle of tendons around shoulder joint: tendons of deep subscapularis, supraspinatus, infraspinatus, and teres minor connect scapula to humerus Muscles of the Pectoral Girdle and Upper Limbs

2. Muscles That Move the Humerus Muscles of the Pectoral Girdle and Upper Limbs

2. Muscles That Move the Humerus Muscles of the Pectoral Girdle and Upper Limbs

3. Muscles That Move the Forearm Forearm = 4 main types of action: flexion, extension, pronation, supination  forearm flexors (ant flexor compartment of the arm) = 1. biceps brachii (two-headed muscle crossing shoulder and elbow joints to flex forearm, also taking part in supinating the forearm at radioulnar joints and flexing arm at shoulder joint), 2. brachialis (provides additional power in flexing forearm), 3. brachioradialis (flex forearm quickly or help lift a load slowly).  extensors = triceps brachii and anconeus.  pronators = pronator teres and pronator quadratus  supinator = only one that turns forearm anteriorly Muscles of the Pectoral Girdle and Upper Limbs

3. Muscles That Move the Forearm Muscles of the Pectoral Girdle and Upper Limbs

3. Muscles That Move the Forearm Muscles of the Pectoral Girdle and Upper Limbs

3. Muscles That Move the Forearm Muscles of the Pectoral Girdle and Upper Limbs

4. Muscles That Move the Wrist, Hand, and Fingers Wrist, hand, and finger movements are facilitated by 2 groups of muscles: extrinsic muscles of the hand = forearm is origin intrinsic muscles of the hand = palm is origin Muscles of the Pectoral Girdle and Upper Limbs

4a. Extrinsic muscles  superficial anterior flexor compartment of the forearm = originate on humerus and insert onto different parts of hand: (bulk of forearm), -from lateral to medial- flexor carpi radialis, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis (= flexes hand as well as digits at the knuckles, allowing for rapid finger movements, as in typing or playing a musical instrument (Carpal Tunnel Syndrome).  deep anterior compartment = flexion and bends fingers to make a fist: flexor pollicis longus and flexor digitorum profundus.  superficial posterior extensor compartment of the forearm = originate on the humerus: extensor radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris.  deep posterior extensor compartment of the forearm= originate on radius and ulna: abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and extensor indicis. tendons of forearm muscles attach to wrist and extend into the hand: fibrous bands called retinacula sheath tendons at the wrist  flexor retinaculum extends over hand palmar surface, while extensor retinaculum extends over hand dorsal surface Muscles of the Pectoral Girdle and Upper Limbs

4a. Extrinsic muscles Muscles of the Pectoral Girdle and Upper Limbs

= both originate and insert within hand, allowing to make precise 4b. Intrinsic muscles movements for actions, such as typing or writing, divided into 3 groups: 1.thenar muscles (on radial aspect of the palm, abductor pollicis brevis, opponens pollicis, flexor pollicis brevis, and the adductor pollicis - form thenar eminence, rounded contour of thumb base, all act on thumb), 2. hypothenar muscles (on medial aspect, abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi - form hypothenar eminence, rounded contour of little finger, all act on little finger), 3.intermediate muscles (midpalmar, act on all fingers, lumbrical, palmar interossei, and dorsal interossei). Muscles of the Pectoral Girdle and Upper Limbs

4b. Intrinsic muscles Appendicular Muscles of Pelvic Girdle and Lower Limbs

Pelvic girdle = less range of motion because designed to stabilize and support body. Muscles of the Thigh Gluteal Region Muscles That Move the Femur Most muscles that insert on femur and move it, originate on pelvic girdle.  psoas major and iliacus = iliopsoas group.  gluteal group = some of the largest and most powerful muscles in the body: 1. gluteus maximus (largest); 2. gluteus medius (deep to gluteus maximus); 3. gluteus minimus (deep to the gluteus medius, smallest of the trio)  tensor fascia lata = thick, squarish muscle in superior aspect of lateral thigh (acts as a synergist of gluteus medius and iliopsoas in flexing and abducting the thigh + stabilize lateral aspect of the knee)  piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femori = deep to gluteus maximus, laterally rotate femur at the hip.  adductor longus, adductor brevis, and adductor magnus = medially and laterally rotate thigh depending on the placement of the foot (adductor longus flexes thigh, whereas adductor magnus extends it).  pectineus adducts and flexes femur at hip as well (located in femoral triangle, also includes the femoral nerve, the femoral artery, the femoral vein, and the deep inguinal lymph nodes Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles of the Thigh

Gluteal Region Muscles That Move the Femur Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles of the Thigh

Gluteal Region Muscles That Move the Femur Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles of the Thigh Thigh Muscles That Move the Femur, Tibia, and Fibula Deep fascia in thigh separates into: 1.medial (responsible for adducting the femur at the hip) = 1.gracilis (strap-like) along with adductor longus, adductor brevis, adductor magnus, and pectineus, adducts thigh in addition to flexing leg at knee. 2.anterior (flex thigh and extend leg) = 1. quadriceps femoris group (= 4 muscles extending and stabilizing knee: rectus femoris, vastus lateralis, vastus medialis, vastus intermedius  patellar tendon common to all four inserting into patella and continuing below it as patellar ligament, attaches to tibial tuberosity 2. sartorius (band-like muscle extending from ant. Sup. iliac spine to medial side of proximal tibia  flexes leg at knee and flexes, abducts, and laterally rotates leg at hip = to sit cross-legged) 3.posterior compartments (flex leg and extend thigh) = (hamstring group flexing knee) 1.biceps femoris, 2.semitendinosus, 3.semimembranosus (tendons form popliteal fossa = diamond-shaped space at back of knee). Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles of the Thigh

Thigh Muscles That Move the Femur, Tibia, and Fibula Appendicular Muscles of Pelvic Girdle and Lower Limbs Muscles That Move the Feet and Toes deep fascia separate muscles of the leg into 3 compartments: 1. Ant = 1. tibialis anterior (long and thick muscle on lateral surface of tibia), 2. extensor hallucis longus, 3. extensor digitorum longus (all contribute to raising front of foot), 4. fibularis tertius (associated with extensor digitorum longus, but not present in all people) [thick bands of connective tissue = superior extensor retinaculum (transverse ligament of the ankle) and inferior extensor retinaculum  hold tendons of these muscles in place during dorsiflexion] 2. Lateral = 1. fibularis longus (peroneus longus) and 2. fibularis brevis (p. brevis) 3. Post = • superficial = [all insert onto strong calcaneal tendon (Achilles tendon) inserting into calcaneal bone] muscles large and strong keeping humans upright = 1. gastrocnemius (most superficial and visible muscle of the calf) 2. soleus (deep to gastrocnemius, wide, flat) 3. plantaris (running obliquely between two) 4. tibialis posterior • deep = 1. popliteus, 2.flexor digitorum longus, 3. flexor hallucis longus, 4. tibialis posterior Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles That Move the Feet and Toes Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles That Move the Feet and Toes Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles That Move the Feet and Toes

foot also has intrinsic muscles = originate and insert within it, primarily providing support for foot and its arch and contributing to movements of toes, 2 groups: dorsal group = 1. extensor digitorum brevis plantar group = 4 layers, starting with the most superficial.

[principal support for longitudinal arch of foot = deep fascia called plantar aponeurosis, running from calcaneus bone to toes]

Appendicular Muscles of Pelvic Girdle and Lower Limbs

Muscles That Move the Feet and Toes Appendicular Muscles of Pelvic Girdle and Lower Limbs Muscles That Move the Feet and Toes

intrinsic

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