Skeletal System Gross Anatomy 7.1 Skeletal System Overview

Chapter 07

Lecture Outline

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• Provides framework • Provides levers upon which muscles act to move the body • Protection of organs • Mineral storage • Hemopoiesis • Energy storage • Components – Bones – Cartilage – Ligaments – Tendons

7-3 Skeletal System Overview

• Terms • Projections – Body: main part – Process: prominent – Head: enlarged end projection – Neck: constriction – Tubercle: small rounded between head and body bump – Margin or border: edge – Tuberosity: knob – Angle: bend – Trochanter: tuberosities – Ramus: branch off body on proximal femur – Condyle: smooth rounded – Epicondyle: near or articular surface above condyle – Facet: small flattened articular surface 7-4 Skeletal System Overview

• Ridges – Line or linea: low ridge • Depressions – Crest or crista: – Fossa: general term prominent ridge for a depression – Spine: very high ridge – Notch: depression in • Openings bone margin – Foramen: hole – Fovea: little pit – Canal or meatus: tunnel – Groove or sulcus: – Fissure: cleft deeper, narrow – Sinus or labyrinth: depression cavity

TABLE 7.2 Anatomical Terms for Bone Features

Term Description Body Main part Head Enlarged, often rounded end Neck Constriction between head and body Margin, border Edge Angle Bend Ramus Branch off the body beyond the angle Condyle Smooth, rounded articular surface Facet Small, flattened aticular surface Ridges Line, linea Low ridge Crest, crista Prominent ridge Spine Very high ridge Projections Process Prominent projection Tubercle Small, rounded bump Tuberosity, tuber Knob; larger than a tubercle Trochanter Tuberosity on the proximal femur Epicondyle Upon a condyle Lingula Flat, tongue-shaped process Hamulus Hook-shaped process Cornu Horn-shaped process Openings Foramen Hole Canal, meatus Tunnel Fissure Cleft Sinus, labyrinth Cavity Depressions Fossa General term for a depression Notch Depression in the margin of a bone Fovea Little pit 7-6 Groove,ulcus Deep, narrow depression The Complete Skeleton Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Axial Skeleton Appendicular Skeleton Axial Skeleton

Skull Skull

Mandible Mandible Hyoid bone

Clavicle

Scapula

Sternum

Ribs Humerus Ribs

Vertebral column Vertebral column Ulna Radius Sacrum Sacrum

Carpal bones Metacarpal bones

Phalanges Coxal Coccyx bone Femur

Patella

Tibia

Fibula

Tarsal bones Metatarsal bones Phalanges 7-7

Bones Number Bones Number

AxialSkeleton Appendicular Skeleton Skull (Cranium) Pectoral Girdle Braincase (neurocranium) Scapula 2 Paired (left and right) Parietal 2 Clavicle 2 Temporal 2 Upper Limb Unpaired (single) Frontal 1 Humerus 2 Sphenoid 1 Ulna 2 Occipital 1 Radius 2 Ethmoid 1 Carpal bones 16 Face (viscerocranium) Metacarpal bones 10 Paired Maxilla 2 Phalanges 28 Zygomatic 2 Total girdle and upper limb bones 64 Palatine 2 Pelvic Girdle Lacrimal 2 Coxal bone 2 Nasal 2 Lower Limb Inferior nasal concha 2 Femur 2 Unpaired Mandible 1 Tibia 2 Vomer 1 Fibula 2 Total skull bones 22 Patella 2 Bones Associated with the Skull Tarsal bones 14 Auditory ossicles Metatarsal bones 10 Malleus 2 Phalanges 28 Incus 2 Total girdle and lower limb bones 62 Stapes 2 Total appendicular skeleton bones 126 Hyoid 1 Total associated bones 7 Total axial skeleton bones 80 Total appendicular skeleton bones 126 Vertebral Column Total bones 206 Cervical vertebrae 7 Thoracic vertebrae 12 Lumbar vertebrae 5 Sacrum 1 Coccyx 1 Total vertebral column bones 26 Rib Cage (Thoracic Cage) Ribs 24 Sternum 1 Total rib cage bones 25 7-8 Total axial skeleton bones 80 7.2 Axial Skeleton • Axial skeleton – Skull – Hyoid bone – Vertebral column – Thoracic (rib) cage

7-9 Superior View of the Skull

Parietal bones – Provides foundation Coronal suture for structures that take Inferior temporal line air, food, and water Superior temporal line into body Sagittal suture

Parietal eminence • Superior view of skull – Parietal bones

Zygomatic arch Occipital bone – Frontal bone

Superior view – Sagittal suture – Coronal suture

7-10 7-11 Posterior View of Skull

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Parietal and occipital Sagittal suture bones are major structures Parietal bones • Lambdoid suture: between parietals and

Lambdoid suture occipital Occipital bone External occipital protuberance • Sutural bones may be present: variable Superior Temporal bone nuchal line Occipitomastoid Inferior • External occipital suture nuchal line Mastoid process protuberance Occipital condyle Zygom aticarch – Ligamentum nuchae: Helps keep head erect • Nuchal lines: Neck muscle attachment points Posterior view 7-12 Lateral View of Skull

Coronal suture

• Squamous suture: joins the parietal Superior temporal line Frontal bone and temporal bone Inferior temporal line Parietal bone

Supraorbital foramen Squamous suture • Features of the temporal bone Supraorbital margin Temporal bone Sphenoid bone (greater wing) Nasal bone Occipital bone – External auditory meatus Lacrimal bone Nasolacrimal canal Lambdoid suture Infraorbital foramen – Mastoid process Mandibular condyle Zygomatic bone External auditory canal Coronoid process Occipitomastoid suture of mandible – Temporal lines Mastoid process Maxilla Styloid process Alveolar processes – Zygomatic process of the zygomatic Zygomatic process Zygomatic arch of temporal bone Temporal process of zygomatic bone arch Mental foramen Mandibular ramus Angle of mandible Mandible Body of mandible Mental protuberance • Greater wing of the sphenoid bone Lateral view anterior to the temporal bone • Zygomatic bones with its temporal

process of the zygomatic arch • Maxilla

• Mandible. Articulates with the temporal bone. Body, ramus, condyle, and coronoid process 7-13 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Frontal bone

Supraorbital margin

Zygomatic arch

Nasal bone

Zygomatic bone

Maxilla

Mastoid process

Mental protuberance Mandible Angle of mandible

Frontal bone

Parietal bone Coronal suture • Major structures are frontal Supraorbital foramen Glabella Optic canal bone, zygomatic bones, Supraorbital margin Orbital plate of frontal bone

Sphenoid bone (greater wing) Temporal bone maxillae, and mandible Superior orbital fissure Nasal bone Infraorbital margin Lacrimal bone • Maxilla and mandible bear Zygomatic bone Infraorbital foramen

Perpendicular plate Middle nasal concha Nasal of ethmoid bone teeth septum Inferior nasal concha Vomer Nasal cavity Anterior nasal spine • Orbits. Cone-shaped fossae

Maxilla Oblique line of mandible

Mandible with their apices oriented Alveolar processes Mandibular symphysis Body of mandible

Mental foramen posteriorly Mental protuberance Anterior view – Nasolacrimal canal – Optic foramen

Glabella Frontal bone

Supraorbital margin Zygomatic bone

Maxilla Mandible Mental protuberance

Frontal bone

Optic canal Superior orbital fissure Posterior and anterior ethmoidal for amina

Sphenoid Lesser wing Ethmoid bone bone Greater wing Lacrimal bone Palatine bone Opening to nasolacrimal canal Zygomatic bone Maxilla

Inferior orbital fissure Infraorbital foramen Infraorbital groove

Anterior view

Frontal bone Crista galli Frontal sinus Cribriform plate • Nasal cavity. Pear-shaped, Olfactory foramina Nasal bone Sphenoidal sinus open anteriorly Perpendicular plate Nasal of ethmoid bone Sphenoid bone septum Septal cartilage • Nasal septum divides nasal Vomer Greater alar cartilage cavity into right and left Anterior Horizontal plate nasal spine of palatine bone Hard palate Palatine process halves of maxilla Central incisor Incisive canal – Bony part is vomer and (a) Medial view perpendicular plate of the Frontal bone Lacrimal bone Olfactory recess ethmoid Frontal sinus Superior nasal concha Part of Middle nasal concha ethmoid bone – Hyaline cartilage anterior part Nasal bone

Sphenoidal sinus Maxilla bone • Nasal conchae: form lateral Sphenoid bone Lateral nasal cartilage Inferior nasal concha walls Greater alar cartilage Vertical plate Palatine bone Horizontal plate

Medial pterygoid plate – Inferior: separate bones

Palatine process of maxilla Lateral incisor – Middle and superior:

(b) Medial view projections of the ethmoid – Increase surface of nasal cavity

7-18 7-19 Paranasal Sinuses • Associated with the bones of the nasal cavity • Functions – Decrease skull weight – Resonating chambers • Named for bones in which they are found

Ethmoidal labyrinth (sinuses) Maxillary sinus

(b)

Frontal sinus

Ethmoidal labyrinth (sinuses)

Sphenoidal sinus

(a) c-d: © Jupiter Media/Alamy 7-20 Interior of the Cranial Cavity

• Cranial cavity: occupied by the brain • Floor divided into anterior, middle, and posterior fossae • Crista galli: prominent ridge in center of anterior fossa. Point of attachment for the dura mater (one of the meninges) • Olfactory fossae lateral to crista galli. Olfactory bulb within – Cribriform plate of the ethmoid forms floor of olfactory fossae – Olfactory nerves pass through the foramina of the cribriform plate • Sella turcica: part of sphenoid bone that houses the pituitary gland • Foramen magnum: opening where brain attaches to spinal cord

7-21 Interior of the Cranial Cavity

Crista galli Olfactory foramina Ethmoid bone Anterior cranial fossa Cribriform plate Frontal bone

Lesser wing Sphenoid Optic canal bone Greater wing Sella turcica Foramen rotundum Foramen ovale Middle cranial fossa Foramen spinosum Carotid canal Squamous portion (foramen lacerum is inferior) Temporal Petrous portion bone

Hypoglossal canal Internal auditory canal Foramen magnum Jugular foramen Parietal bone Posterior cranial fossa

Occipital bone

Superior view 7-22 Inferior View of Skull • Foramina – Foramen magnum: spinal cord exits and vertebral arteries enter – Carotid canals: internal carotid arteries – Foramen lacerum: internal carotid – Jugular foramen: internal jugular veins • Specialized surfaces – Occipital condyles: articulation between skull and vertebral column – Styloid processes: attachment site for muscles that move the tongue – Mandibular fossa: site of articulation with mandibular condyles – Medial and later pterygoid plates: parts of sphenoid bone that surround posterior opening of nasal cavities – Vomer: posterior portion of nasal septum – Hard palate: floor of the nasal cavity. With the soft palate, separates nasal from oral cavities

7-23 Inferior View of Skull

Incisive fossa Maxilla

Palatine process of maxillary bone Zygomatic bone Hard Horizontal plate of palatine bone palate

Anterior palatine foramen Pterygoid hamulus Posterior palatine foramen Inferior orbital fissure Temporal process of zygomatic bone Lateral pterygoid plate Zygomatic arch Sphenoid Zygomatic process bone Greater wing of temporal bone Medial pterygoid plate Vomer Foramen ovale Foramen lacerum Foramen spinosum Styloid process Mandibular fossa Carotid canal (posteroinferior opening) External auditory canal Stylomastoid foramen Jugular foramen Mastoid process

Temporal bone Occipital condyle Foramen magnum Occipital bone

Inferior nuchal line

Superior nuchal line External occipital protuberance

7-24 Inferior view 7-25 Bones of the Skull • Twenty-two bones plus six auditory ossicles that function in hearing • Of the twenty-two, two portions- – Braincase (Neurocranium) • Surrounds and protects brain • Parietals, temporals, frontal, occipital, sphenoid, ethmoid – Facial bones (Viscerocranium) • Protect major sensory organs- eyes, nose, and tongue • Provide attachment sites for muscles of mastication, facial expression, and eye movement • Maxilla and mandible have alveolar processes and sockets for tooth attachment • Maxillae, zygomatics, palatines, lacrimals, nasals, inferior nasal conchae, mandible, vomer. Note: frontal and ethmoid contribute to the face and mandible is not part of the skull

TABLE 7.7 Skull Bones (a) Parietal Bone (Right)—Lateral View

Landmark Description Parietal eminence The widest part of the head is from one parietal eminence to the other.

Superior and inferior Attachment point for temporallines temporalis muscle Special Feature Forms lateral wall of skull

Parietal eminence

Superior tem poralline Inferior temporal line

TABLE 7.7 Skull Bones

(b) Temporal Bone (Right)—Lateral and Medial Views

Landmark Description Carotid canal (shownin Canal through which the internal carotid figures 7.11 and 7.12 ) artery enters the cranial cavity

External auditory canal External canal of the ear; carries sound to the ear

Internal auditory canal Opening through which the facial (cranial (shown in figure 7.11 ) nerve VII) and vestibulocochlear (cranial nerve VIII) nerves enter the petrous portion Squamous of the temporal bone portion Zygomatic Forms one side of jugular Foramen through which the internal jugular process for a men (shown in figures vein exits the cranial cavity 7.11 and 7.12 ) Mandibular fossa Mandibular fossa Articulation point between the mandible Mastoid External auditory and skull process canal Styloid process Mastoid process Attachment point for muscles moving the head and for a hyoid muscle Lateral view Middle cranial fossa Depression in the floor of the cranial cavity (shown in figure 7.11) formed by the temporall obesof the brain

Petrous portion Thick portion of the temporal bone (shown in figure 7.11) Squamous portion Flat, lateral portion of the temporal bone (shown in figure 7.11 )

Styloid process Attachment for muscles of the tongue, throat, and hyoid bone Squamous portion Stylomastoid foramen Foramen through which the facial nerve (shown infigure 7.12 ) (cranial nerve VII ) exits the skull Zygomatic process Petrous portion Helps form the bony bridge extending from the cheek to just anterior to the ear; attachment for a muscle that moves the Internal auditory mandible Mastoid canal process Special Features Styloid process Contains the middle and inner ear and the mastoid air cells Place where the mandible articulates with the rest of the skull Medial view 7-28 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

TABLE 7.7 Skull Bones—Continued

Landmark Description Glabella Area between the supraorbital margins Nasal spine Superior part of the nasal bridge Orbital plate Roof of the orbit Supraorbital foramenar Opening through which nerves and vessels exit the skull to the skin of the forehead

Supraorbital margin Ridge forming the anterior superior border of the orbit

Zygomatic process Connects to the zygomatic bone; helps form the lateral margin of the orbit

Special Features Forms the forehead and roof of the orbit Contains the frontal sinus Glabella Supraorbital Supraorbital foramen margin Orbital plate Zygomatic process Nasal spine

TABLE 7.7 Skull Bones—Continued (d) Sphenoid Bone—Superior and Posterior Views

Landmark Description Body Thickest part of the bone; articulates with the occipital bone Foramen ovale Opening through which a branch of the trigeminal nerve (cranial nerve V) exits the cranial cavity Foramen rotundum Opening through which a branch of the trigeminal nerve (cranial nerve V) exits Optic canal the cranial cavity Foramen spinosum Opening through which a major artery to Lesser Superior the meninges (membranes around the wing orbital brain) enters the cranial cavity fissure Greater Greater wing Forms the fl oor of the middle cranial wing Sella fossa; several foramina pass through turcica this wing Foramen rotundum Lateral pterygoid plate Attachment point for muscles of Foramen ovale Groove of mastication (chewing) Foramen spinosum carotid Lesser wing Superior border of the superior orbital Superior view canal fissure Medial pterygoid plate Posterolateral walls of the nasal cavity

Optic canal Opening through which the optic nerve (cranial nerve II) passes from the orbit to the cranial cavity Lesser Superior Pterygoid canal Opening through which nerves and wing orbital vessels exit the cranial cavity Greater fissure wing Body Pterygoid hamulus Process around which the tendon passes from a muscle to the soft palate Sella turcica Fossa containing the pituitary gland Foramen rotundum Superior orbital Opening through which nerves and Pterygoid canal Lateral fissure vessels enter the orbit from the cranial pterygoid cavity plate Pterygoid hamulus Medial Special Feature pterygoid Contains the sphenoidal sinus Posterior view plate 7-30 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TABLE 7.7 Skull Bones—Continued (e) Occipital Bone—Inferior View

Landmark Description Condyle Articulation point between the skull and first vertebra External occipital Attachment point for a strong ligament protuberance (nuchal ligament) in the back of the neck

Foramen magnum Opening around the point where the brain and spinal cord connect Anterior Hypoglossal canal Opening through which the (shown in figure 7.11) hypoglossal nerve (cranial nerve XII) passes Inferior nuchal line Attachment point for neck muscles Posterior cranial fossa Condyle Depression in the posterior of the (shown in figure 7.11) cranial cavity formed by the cerebellum Foramen magnum Superior nuchal line Attachment point for neck muscles Special Feature

Inferior Forms the base of the skull nuchalline

Superior nuchalline

External occipital protuberance Posterior

Landmark Description Frontal process Connection to the frontal bone; helps form the lateral margin of the orbit

Infraorbital margin Ridge forming the inferior border of the orbit

Temporal process Helps form the bony bridge from the cheek to just anterior to the Frontal ear process Zygomaticofacial Opening through which a foramen nerve and vessels exit the orbit to the face

Zygomaticofacial Special Features foramen Temporal Forms the prominence of the cheek process Infraorbital Forms the anterolateral wall of the orbit margin

Maxillary process

TABLE 7.7 Skull Bones—Continued (g) Ethmoid Bone—Superior, Lateral, and Anterior Views

Land mark Description Cribriformplate Contains numerous olfactory foramina through which branches of the olfactory nerve (cranial nerve I) enter the cranial cavity from the nasal cavity Cristagalli Attachment for meninges (membranes around brain) Anterior Ethmoidalforamina Openings through which nerves and Perpendicular (shown in figure7.8) vessels pass from the orbit to the nasal plate cavity Middle nasal concha Ridge extending into the nasal cavity; Ethmoidal labyrinth increases surface area, helps warm and Crista galli (sinuses) moisten air in the cavity Orbital plate Forms the medial wall of the orbit Cribriform Perpendicular plate Forms the superior portion of the nasal plate septum Superior nasal concha Ridge extending into the nasal cavity; Orbital plate increases surface area, helps warm and moisten air in the cavity Special Features Forms part of the nasal septum and part of the lateral walls and roof of the nasal cavity Posterior

Contains the ethmoidal labyrinth, or ethmoidal sinuses; the labyrinth Superior view is divided into anterior, middle, and posterior ethmoidal cells

Crista galli

Ethmoidal labyrinth (sinuses) Orbital plate

Posterior Anterior

Middle nasal Perpendicular concha plate

Lateral view

Crista galli

Orbital plate Ethmoidal labyrinth Superior (sinuses) nasal concha Middle Perpendicular nasal concha plate 7-33 Anterior view Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TABLE 7.7 Skull Bones—Continued (h) Maxilla (Right)—Medial and Lateral Views

Landmark Description Alveolar process Ridge containing the teeth Anterior nasal spine Forms part of the nasal septum Frontal process Forms the sides of the nasal bridge Incisive canal Opening through which a nerve exits the nasal cavity to the roof of the oral cavity Infraorbital foramen Opening through which a nerve and vessels exit the orbit to the face Frontal process Orbital surface Forms the fl oor of the orbit Palatine process Forms the anterior two-thirds of the hard palate Maxillary sinus Maxillary Tuberosity Lump posterior to the last maxillary molar tooth Zygomatic process Connection to the zygomatic bone; helps form the interior margin of the orbit Special Features Palatine process Contains the maxillary sinus and maxillary teeth Forms part of nasolacrimal canal Incisive canal Alveolar process

Molars Premolars Canine Incisors

Medial view

Frontal Notch for process lacrimal bone

Orbital surface Infraorbital foramen

Zygomatic Anterior process nasal spine Tuberosity Alveolar process

Incisors Canine Premolars Molars 7-34 Lateral view Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TABLE 7.7 Skull Bones—Continued (i) Palatine Bone (Right)—Medial and Anterior Views

Landmark Description Horizontal plate Forms the posterior one-third of the hard palate Vertical plate Forms part of the lateral nasal wall Special Feature Helps form part of the hard palate and a small part of the wall of the orbit

Vertical plate Vertical plate

Horizontal plate Horizontal plate

Medial view Anterior view

Special Features Forms a small portion of the orbital wall Forms part of the nasolacrimal canal

Lacrimal bone Nasolacrimal canal

7-36 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TABLE 7.7 Skull Bones—Continued (k) Nasal Bone (Right)—Anterolateral View Special Feature Forms the bridge of the nose

Nasal bone

Landmark Description Alveolar process Ridge containing the teeth Angle Corner between the body and ramus Body Major, horizontal portion of the Coronoid bone process Condylar process Extension containing the Mandibular mandibular condyle notch Molars Coronoid process Attachment for a muscle of Mandibular mastication Premolars condyle (head) Canine Condylar Mandibular condyle Helps form the temporo- mandibular joint (the point Incisors process of articulation between the Ramus mandible and the rest of the skull) Mandibular foramen Mandibular foramen Opening through which nerves Lingula and vessels to the mandibular teeth enter the bone Alveolar process Mandibular notch Depression between the condylar process and the coronoid process Mylohyoid line Angle Mental foramen Opening through which a nerve Body and vessels exit the mandible to the skin of the chin Medial view Mylohyoid line Attachment point of the mylohyoid muscle Mandibular Coronoid Oblique line Ridge from the anterior edge of notch process the ramus onto the body of the Mandibular Molars mandible condyle Condylar Premolars Ramus Major, nearly vertical portion of process Canine the bone Special Features Incisors Oblique line The only bone in the skull that is freely movable relative to the rest of the skull bones Ramus Alveolar Holds the lower teeth process Body Mental Angle foramen 7-38 Lateral view Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TABLE 7.7 Skull Bones—Continued (m) Vomer—Anterior and Lateral Views

Landmark Description Alae Attachment points between the vomer and sphenoid Vertical plate Forms part of the nasal septum Alae Special Feature Forms most of the posterior and inferior portions of the nasal septum Alae

Vertical Vertical plate plate

Anterior view Lateral view

7-39 Hyoid Bone

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TABLE 7.8 Hyoid Bone—Anterior and Lateral Views Landmark Description Body Major portion of the bone Greater cornu Attachment point for muscles and ligaments Lesser cornu Attachment point for muscles and ligaments Special Features One of the few bones of the body that does not articulate with another bone Attached to the skull by muscles and ligaments Greater cornu

Lesser cornu Body

Anterior view

Lesser cornu Greater cornu

Body

Lateral view

7-40 Vertebral Column

• Functions • Twenty-six bones in adult; 33-34 – Supports weight of in embryo head and trunk – 5 fuse to form sacrum – 4 or 5 coccygeal fuse to form – Protects the spinal cord the coccyx – Allows spinal nerves to • Regions exit the spinal cord – Cervical (7 vertebrae) – Provides site for – Thoracic (12 vertebrae) muscle attachment – Lumbar (5 vertebrae) – Permits movement of – Sacral bone (1) head and trunk – Coccygeal bone (1)

First cervical vertebra (atlas) Vertebral Column Second cervical vertebra Cervical (axis) region (convex • Four major curvatures in adults anteriorly)

Seventh cervical vertebra – Cervical: anterior First thoracic vertebra – Thoracic: posterior – Lumbar: anterior Thoracic region (concave – Sacral and coccygeal: posterior anteriorly)

Intervertebral foramina • At birth, column is C shaped

Body – When head is raised, cervical curve Intervertebral disk appears Twelfth thoracic vertebra – When sitting and walking begin, First lumbar vertebra lumbar curve develops

Lumbar region • Abnormal curvatures (convex Transverse process anteriorly) Spinous process – Lordosis. Exaggeration of lumbar

Fifth lumbar vertebra – Kyphosis. Exaggeration of thoracic Sacral promontory – Scoliosis. Lateral, often accompanied by kyphosis Sacral and Sacrum coccygeal regions (concave anteriorly) Coccyx 7-42

L a te ral view General Features of the Vertebrae

TABLE 7.9 General Structure of a Vertebra

Feature Description

Body Disk-shaped; usually the largest part with fl at surfaces directed superiorly and inferiorly; forms the anterior wall of the vertebral foramen; intervertebral disks are located between the bodies

Vertebral foramen Hole in each vertebra through which the spinal cord passes; adjacent vertebral foramina form the vertebral canal

Vertebral arch Forms the lateral and posterior walls of the vertebral foramen; possesses several processes and articular surfaces

Pedicle Foot of the arch with one on each side; forms the lateral walls of the vertebral foramen

Lamina Posterior part of the arch; forms the posterior wall of the vertebral foramen

Transverse process Process projecting laterally from the junction of the lamina and pedicle; a site of muscle attachment

Spinous process Process projecting posteriorly at the point where the two laminae join; a site of muscle attachment; strengthens the vertebral column and allows for movement

Articular processes Superior and inferior projections containing articular facets where vertebrae articulate with each other; strengthen the vertebral column and allow for movement

Intervertebral notches Form intervertebral foramina between two adjacent vertebrae through which spinal nerves exit the vertebral canal

TABLE 7.9 General Structure of a Vertebra

Body (cut) Spinous Transverse process Part of process vertebral Lamina canal

Superior Vertebral Intervertebral articular arch disk facet Superior Pedicle articular process

Vertebral Vertebral Spinous foramen foramina process Body (cut) Lateral view, ( a ) Superior view ( b ) Sagittal section

Anterior Posterior Anterior Posterior Superior articular process

Transverse process Inferior intervertebral notch of superior Pedicle vertebra Intervertebral Inferior articular Space for foramen process of Superior intervertebral intervertebral superior vertebra notch of inferior disk vertebra Superior articular process of inferior vertebra

Spinous processes Body 7-44 ( c ) ( d ) Spina Bifida • Lamina of vertebrae: can be removed (laminectomy) when they inhibit a surgery such as a disc removal. • Spina bifida: failure of the laminae to form or to fuse together during development. Can affect the spinal cord. Most often occurs in lumbar region.

Dura mater Skin of back

Enlarged fluid-filled space

Back muscles Spinal cord

Cauda equina Incomplete Body of first vertebral arch lumbar vertebra

Superior view 7-45 Intervertebral Disks

Vertebral body • Functions Annulus Intervertebral fibrosus – Provide support disk Nucleus pulposus Intervertebral – Prevent vertebrae rubbing foramen against each other

(a) Lateral view • Consist of – Annulus fibrosus: external – Nucleus pulposus: internal and Annulus fibrosus gelatinous

Nucleus • Becomes compressed with pulposus age and height decreases • With age, more susceptible to herniation (b) Superior view 7-46 Herniated or Ruptured Disk Part of the fibrosus has been removed to expose the pulposus. Breakage or ballooning of the annulus fibrosus with a partial or complete release of the nucleus pulposus. May push against spinal nerves impairing function and causing pain.

Spinous process

Transverse process Compressed Spinal cord spinal nerve root in in vertebral intervertebral foramen canal Herniated portion of disk

Nucleus pulposus Intervertebral Annulus fibrosus disk

Superior articular Superior articular facet Superior process Facets for rib Transverse articular Transverse articulation process process process Transverse Body Body Body process Spinous Transverse Inferior Spinous process foramen articular process Spinous Inferior facet process articular facet

Body Absent in C1, small in others Medium-sized with articular facets for ribs Large

Transverse process Transverse foramen Articular facets for ribs, except T11 and T12 Square

Spinous process Absent in C1, bifid in others, except C7 Long, angled inferiorly Square

Articular facets Face superior/inferior Face obliquely Face medial/lateral

7-48 Cervical Vertebrae • Superior seven vertebrae • Have very small bodies, tend to have bifid spinous processes, and have transverse foramina • Atlas: first cervical vertebra – Articulates with skull and allows “yes” movement – No body and no spinous process • Axis: second cervical vertebra – Dens or odontoid process extends superiorly into the vertebral foramen of the atlas – Allows rotation of the atlas on the axis, the “no” movement • Vertebral prominence: most prominent spinous process in area. Usually 7th cervical • Superior articular facets face superiorly; inferior facets face inferiorly

Posterior arch Transverse Superior articular facet process Vertebral foramen Posterior arch Superior articular facet (articulates Anterior arch with occipital condyle) Facet for dens Transverse Anterior arch Transverse foramen process (a) Atlas (first cervical vertebra), superior view (b) Atlas, lateral view

Spinous process (bifid) Dens Spinous process Transverse Posterior arch Superior process articular Vertebral foramen facet Transverse Superior foramen Body articular Body Transverse Dens facet foramen

Dens of axis Spinous process Anterior (bifid) arch Lamina Atlas Transverse Pedicle ligament Transverse Vertebral foramen foramen Superior articular Posterior arch Transverse facet process Body Axis

(e) Atlas and axis articulated, superior view (f) Fifth cervical vertebra, superior view

Superior articular process C1 Dens Transverse process C2 Spinous process Vertebral C3 Bifid tip Spinous body of spinous C4 processes process Body Inferior articular C5 Transverse process process Transverse foramen C6 Inferior articular Transverse facet C7 foramen 7-50 (g) Fifth cervical vertebra, lateral view (h) Anterolateral view (h) © Trent Stephens Thoracic Vertebrae

Lamina Spinous process Vertebral foramen Transverse • Long, thin spinous processes process Articular facet for tubercle of rib Superior articular Superior articular directed inferiorly process facet Pedicle Superior articular facet for rib head Body • Long transverse processes

(a) Superior view • Articular facets on transverse

Superior articular process processes for ribs (first 10 Superior articular facet Superior intervertebral notch Pedicle thoracic vertebrae) Superior articular Transverse process Posterior facet for rib head Articular facet for tube rcle of rib Anterior Body Lamina • Facets on body for Articular Inferior articular process T1 Inferior articular facet for facet for rib head rib head articulation with ribs Spinous process T2 Inferior intervertebral Articular notch T3 facet for tubercle of rib • Most ribs have heads that (b) Lateral view Transverse Body T4 process Spinous articulate with two sequential Space for T5 process intervertebral disk T6 vertebrae Intervertebral foramen T7

7-51 Lumbar Vertebrae

Spinous process

Lamina

Transverse Superior articular • Large thick bodies process facet Pedicle Vertebral foramen

• Heavy rectangular transverse Body and spinous processes (a) Superior view • Superior articular facets face Superior articular process

medially; inferior articular Vertebral Transverse body process facets face laterally Spinous process Pedicle

Inferior articular Inferior articular – Adds strength process facet – Limits rotation (b) Lateral view

L1 Intervertebral foramen

Body Spinous L2 process

Transverse L3 process Space for intervertebral disk L4

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Sacrum Ala Sacr al – Alae: superior lateral parts of promontory Anterior fused transverse processes sacral for amina – Auricular surface: articulates with pelvic bone Transverse lines – Median sacral crest: partially fused spinous processes – Sacral hiatus: site of Coccyx anesthesia injection

(a) Anterior view Superior articular facet – Sacral foramina: Ala (articulates with fifth Sacral canal intervertebral foramina lumbar vertebra) Auricular – Sacral promontory: anterior surface Median sacral (articulates crest edge of body of first vertebra. with coxal bone) Marks separation of abdominal Posterior sacral and pelvic cavities foramina Sacral hiatus • Coccyx: tailbone

Coccyx 7-53 (b) Posterior view Rib Cage • Functions

Seventh cervical vertebra – Forms semi-rigid chamber for Clavicle First thoracic vertebra Jugular notch 1 respiration

Sternal 2 angle • Parts 3 True ribs Costal 4 – Thoracic vertebrae cartilage Manubrium 5 Body Sternum – Ribs (12 pair) 6 Xiphoid process 7 • True or Vertebrosternal: 8 11 T12 False ribs superior seven. Attach 9 (8–12) 12 L1 Floating ribs 10 directly to sternum via Head of rib set against the inferior (a) Anterior view articular facet costal cartilages of the superior vertebra

Head of rib set • False: inferior five Head against the Articular facet for superior articular Neck transverse process facet of the inferior – Vertebrochondral (3) Tubercle of vertebra vertebra Angle Tubercle of rib joined by common Sternal end set against the Body articular facet (b) Inferior view on the transverse cartilage to sternum process of the inferior vertebra

Angle of rib – Floating or vertebral (2) do not attach to Body of rib (c) Lateral view sternum (c) © Trent Stephens 7-54 Sternum • Manubrium – Articulates with first rib and clavicle – Jugular notch superiorly – Sternal angle: point where manubrium joins body. Second rib articulates here • Body: third through seventh ribs articulate – Also called gladiolus • Xiphoid process: inferior tip

Seventh cervical vertebra Clavicle First thoracic vertebra Jugular notch 1

Sternal 2 angle 3 True ribs Costal 4 cartilage Manubrium 5 Body Sternum 6 Xiphoid process 7

8 11 T12 False ribs 9 (8–12) 12 L1 Floating ribs 10 7-55

(a) Anterior view 7.3 Appendicular Skeleton

• Girdles Clavicle Pectoral girdle Sacrum Coxal bone Pelvic girdle – Pectoral or shoulder Scapula – Pelvic

Humerus • Upper Limbs Femur – Arm

– Forearm Patella

– Wrist Ulna Upper limb Tibia Lower limb – Hand Radius

Fibula • Lower Limbs Carpal bones

Metacarpal bones – Thigh Tarsal bones Metatarsal Phalanges bones – Leg Phalanges Anterior view Anterior view – Foot

7-56 Pectoral Girdle

Acromion process Acromion process • Scapula (2) Coracoid process Superior angle Coracoid process Superior border Supraglenoid tubercle Scapular notch Glenoid cavity – Acromion process Supraspinous Glenoid cavity fossa

Infraglenoid Scapular spine Infraglenoid tubercle • Forms protective cover tubercle Subscapular fossa Lateral (axillary) border • Attachment for clavicle Infraspinous fossa Medial (vertebral) • Attachment for muscles border

Lateral (axillary) border – Scapular spine: divides View in (d) posterior surface into supra- and infraspinous fossae Inferior angle – Coracoid process: attachment (a) Anterior view (b) Posterior view for muscles Body of clavicle – Glenoid cavity: articulates with Spine of scapula Posterior Supraspinous fossa of scapula humerus Superior border of scapula

Sternal (medial) Acromion process • Clavicle (2): articulates with end of scapula Acromial end Acromial (lateral) of clavicle end Coracoid process acromion and with of scapula

Body of clavicle Anterior

Head Greater tubercle • Head Lesser Anatomical tubercle neck Surgical • Neck: anatomic and neck Intertubercular groove surgical • Tubercles: greater and Deltoid tuberosity lesser • Intertubercular groove Radial groove • Deltoid tuberosity • Capitulum: rounded, articulates with radius Lateral supracondylar ridge Medial supracondylar • Trochlea: spool-shaped, Olecranon ridge Radial fossa Coronoid fossa fossa articulates with ulna Lateral Lateral epicondyle Medial epicondyle epicondyle Capitulum • Epicondyles

Trochlea Trochlea (a) Anterior view (b) Posterior view 7-58 Forearm: Radius

Olecranon process Radial notch of ulna

Head of radius Trochlear View notch in (a) Coronoid process • Medial: thumb side (a) Proximal view

Olecranon process • Proximal end Trochlear notch

Radial notch of ulna Coronoid process Radial notch of ulna Head – Head rotates in radial Ulnar tuberosity Neck notch of ulna. Radial tuberosity – Radial tuberosity: site of biceps brachii insertion Interosseous ridges Ulna • Distal end Radius – Articulates with carpals and ulna – Styloid process

Head Styloid process Styloid process Ulnar notch of radius (b) Anterior view (c) Medial view of ulna 7-59 Forearm: Ulna

Olecranon process Radial notch of ulna • Lateral: little finger side Head of radius Trochlear View notch in (a) Coronoid process • Proximal end (a) Proximal view Olecranon process – Trochlear notch: fits over Trochlear notch Radial notch of ulna Coronoid process Radial notch of ulna trochlea of humerus Head Ulnar tuberosity Neck

– Olecranon process: point Radial tuberosity of elbow – Coronoid process Interosseous ridges Ulna • Distal end

– Head articulates with Radius radius and with carpals – Styloid process

Heads of metacarpal bones (knuckles)

Head of ulna Acromion process

Medial border Lateral epicondyle of scapula

Olecranon Olecranon process process

Medial epicondyle

7-61 Wrist and Hand

• Wrist: eight carpal bones – In order from lateral to medial for proximal row and medial to lateral for distal row: So Long Top Part, Here Comes The Thumb – Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium – As a unit are convex posteriorly and concave anteriorly – Carpal tunnel: on anterior surface. Ligament from tubercle of trapezium to hook of hamate • Hand: five metacarpals (palm of hand); five digits with their phalanges

7-62 Wrist and Hand

Radius Ulna Carpal bones (distal row)

Carpal Scaphoid bone Scaphoid bone Carpal bones Lunate bone Hamate bone Lunate bone Capitate bone bones (proximal Triquetrum bone Triquetrum bone (proximal Trapezoid bone row) Pisiform bone Pisiform bone row) Trapezium bone

1 1 Metacarpal bones 5 2 4 3 2 5 3 4

Proximal phalanx of thumb

Distal phalanx of thumb

Digits Proximal phalanx of finger

Middle phalanx of finger

Distal phalanx of finger

(a) Posterior view (b) Anterior view 7-63 Pelvic Girdle

• Coxal bones and sacrum form ring

Sacroiliac joint • Coxal bones: Right and

Ilium Left Anterior superior iliac spine – Ilium

Coxal bone Pubis – Ischium Acetabulum Symphysis pubis – Pubis Obturator Ischium foramen • Acetabulum: articulates Subpubic angle Anterosuperior view with head of femur • Obturator foramen • Sacrum

Sacrum Coxal bone Pelvic girdle

Femur

Patella

Tibia Lower limb

Fibula

Tarsal bones Metatarsal bones Phalanges Anterior view 7-65 Coxal Bones • Formed as fusion of embryonic ilium, ischium, pubis. All three contribute to acetabulum • Ilium: iliac crest, anterior and posterior superior iliac spines, greater sciatic notch, auricular surface, sacroiliac joint, iliac fossa • Ischium: ischial tuberosity • Pubis: pubic crest, symphysis pubis (pubic symphysis) • Pelvic brim – False (greater pelvis) pelvis superior to brim – True pelvis inferior to brim • Pelvic inlet • Pelvic outlet

Ilium

Cartilage in Acetabulum young pelvis Pubis

Ischium Obturator foramen

(a) Lateral view

Tubercle of iliac crest Iliac crest Auricular surface Ilium (articulates Iliac fossa with sacrum) Anterior superior iliac spine Posterior superior Posterior Anterior inferior iliac spine superior iliac spine Iliac spine Posterior inferior Lunate Arcuate iliac spine surface Linea line Posterior inferior Greater sciatic terminalis Pectineal iliac spine notch Acetabulum line Ischium Greater sciatic Superior pubic ramus notch Ischial spine Pubis Ischial spine Pubic tubercle Lesser sciatic Pubic crest notch Lesser sciatic Inferior pubic ramus notch Ischial ramus Acetabular notch

Ischial tuberosity Obturator foramen 7-67 Ischial ramus (b) Lateral view (c) Medial view Comparison of the Male and Female Pelvis

Sacral promontory Pelvic Ischial Inlet spine (red Pelvic Pelvic dashed brim outlet (blue line) Coccyx Symphysis dashed line) pubis Symphysis pubis Subpubic angle

Male Female (a) Anterosuperior view (b) Anterosuperior view

Sacral promontory Pelvic brim Pelvic inlet

Coccyx

Pelvic outlet 7-68 (c) Medial view 7-69 Thigh

• Femur – Head: articulates with acetabulum – Neck – Trochanters: attachment for muscles that fasten lower extremity to hip • Greater and lesser – Distal condyles: articulate with tibia • Medial and lateral – Epicondyles: ligament attachment • Medial and lateral • Patella or kneecap: sesamoid – In tendon of quadriceps femoris – Changes force relationship between femur and tibia

7-70 Thigh

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Head Head Fovea Greater trochanter Greater trochanter capitis Neck Neck Intertrochanteric line Intertrochanteric crest Lesser trochanter Pectineal line Gluteal tuberosity

Linea aspera

Body (shaft) of femur

Adductor tubercle Medial epicondyle

Lateral epicondyle

Lateral epicondyle Intercondylar fossa Medial Lateral condyle condyle Patellar groove 7-71 (a) Anterior view (b) Posterior view Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Anterior surface

(a) Anterior view

Posterior surface

Medial Lateral facet facet

Intercondylar Leg eminence Lateral • Tibia Medial condyle condyle Apex – Larger and supports most of Head Tibial weight tuberosity Proximal – Tibial tuberosity: attachment articulation of tibia and fibula of quadriceps femoris – Anterior crest: shin – Condyles: medial and lateral; articulate with condyles of Anterior crest femur – Intercondylar eminence Fibula Tibia – Medial malleolus: medial side of ankle • Fibula – Articulates with tibia not Distal articulation femur of tibia and – Lateral malleolus: lateral fibula Lateral Medial wall of ankle malleolus malleolus 7-73 Anterior view Foot: Tarsals, Metatarsals, Phalanges

Talus

Cuboid Tarsal – Proximal row: No Thanks bones Navicular Cow = Navicular, Talus, Medial cuneiform Intermediate cuneiform Metatarsal bones Calcaneus 5 Lateral cuneiform 4 3 2 1 – Distal row: MILC = Proximal phalanx Digits Middle phalanx Distal phalanx Medial, Intermediate and Proximal phalanx of great toe

Distal phalanx Lateral Cuneiforms of great toe (a) Superior view • Metatarsals (5): foot

Talus Fibula Navicular Tibia Intermediate cuneiform • Phalanges: toes Medial cuneiform

Medial longitudinal arch Talus

Lateral Transverse Calcaneus longitudinal arch Cuboid arch

Phalanges Metatarsal bones Tarsal bones (b) Medial inferior view 7-74 Arches of the Foot • Function – Distribute weight of body between heel and ball of foot: weight transferred from the tibia and fibula to the talus. From there, the weight is distributed first to the calcaneus then through the arch system along the lateral side of the foot to the ball (head of the metatarsals). Footprint in wet sand: only heel, lateral margin, ball, and toes of foot imprinted. • Three major arches – Transverse arch – Longitudinal arches: Medial and lateral

7-75