The Skeletal System

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC © BraunS/E+/Getty Images NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION CHAPTER 2 © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION The Skeletal System

After completing this chapter, the student will be able to: 1. describe general anatomy of a bone; 2. recall the types of© bone Jones classified & Bartlett by shape; Learning, LLC © Jones & Bartlett Learning, LLC 3. employ terminologyNOT related FOR to anatomicalSALE OR features DISTRIBUTION of bones; NOT FOR SALE OR DISTRIBUTION 4. realize the functional and structural classifications of joints; and 5. recognize the types of synovial joints.

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOThe skeletal FOR systemSALE ORis comprised DISTRIBUTION of several The bonesNOT are arrangedFOR SALE as a relatively OR DISTRIBUTION solid frame- organs called bones (FIGURE 2.1). The main func- work which supports all the other organs directly or tions of the skeletal system and its bones are: indirectly. It is like the steel beams in a commercial T building. The walls directly attach to the beams. This 1. support (framework), © Jones & Bartlett2. prot ection,Learning, and LLC © Jonesmakes a &solid Bartlett surface Learning,for pictures to LLC hang from and be supported by the walls. The bones are arranged in a NOT FOR SALE3. blood OR DISTRIBUTIONcell formation. NOT FOR SALE OR DISTRIBUTION way so that everything else has a stable platform. Many Most, if not all resources include movement as of the bones are also arranged to protect other organs. a function of the skeletal system. This text takes the For instance, the bones of the rib cage surround and position that the skeletal system is not responsible for protect the heart and the lungs. Bones also play a key movement. As we learned© Jonesin Chapter & Bartlett1, there are Learning, four role LLC in the development of blood© Jones cells. & Bartlett Learning, LLC main types of tissues. OnlyNOT muscularFOR SALE tissue OR has DISTRIBUTION the NOT FOR SALE OR DISTRIBUTION unique characteristic of contractility. That is, whatever a muscle is attached to, it applies force to that object ▸▸ Anatomy and if the force is great enough, moves it. Bone tissue is a sub-type of connective tissue and no form The organs of the skeletal system are the bones, such as of connective© Jones tissue & Bartlettmoves anything. Learning, The LLCnumerous the femur. And,© Jones as you have & Bartlett already learned, Learning, an organ LLC bones NOTdo intersect FOR eachSALE other OR at DISTRIBUTION joints and if not for is a compositionNOT of tissuesFOR SALEand a tissue OR isDISTRIBUTION composed of the arrangement, body movement would be extremely cells and matrix (extracellular material). The different restricted. However, that does not make it a function. tissues that comprise a bone organ are marrow, carti- For instance, under “normal” conditions, the muscles lage, vascular, nervous, and osseous tissue (FIGURE 2.2). © Jonesdo & not Bartlett act unless Learning, the nervous LLC system “tells” it to do so. © JonesAnd, different & Bartlett types Learning, of cells comprise LLC these tissues. NOT FORBut, SALE movement OR isDISTRIBUTION not normally listed as a main func- NOTOsseous FOR meansSALE bone. OR DISTRIBUTIONSo, osseous tissue is a tissue tion of the nervous system. that is composed of bone cells. This can be confusing.

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Support Protection The skeleton provides The skeleton protects a structure for the body. vital organs.

© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Blood Cells Haematopoiesis, a fancy name for the development of blood cells, which occurs in the bone marrow. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

FIGURE 2.1 The Skeletal System.

Bone Marrow

Bone Cell © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning,(osteocyte) LLC NOT FOR SALE OR DISTRIBUTION Cartilage NOT FOR SALE OR DISTRIBUTION FIGURE 2.2 The Tissues of a Bone.

© JonesSo, this & Bartlett text will Learning, establish some LLC distinctions to lessen © Jones & Bartlett Learning, LLC that. The wordbone will refer to an entire organ. The NOT FOR SALE OR DISTRIBUTION NOT FORterm SALE bone tissue OR DISTRIBUTION (tissue of a bone) will refer to any or all of the different tissues of a bone organ. Osseous tissue will refer only to the specific tissue of a bone Spongy Bone that is comprised of bone cells. Bone cells, also known Filled with as osteocytes, are the cells© Jonesof osseous & tissue.Bartlett Learning, LLC © JonesRed Marrow & Bartlett Learning, LLC Osseous tissue is a NOTcomposite FOR of SALE about two-thirds OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION inorganic matter and one-third organic matter. The inorganic portion is about 85% calcium phosphate, Compact Bone 10% calcium carbonate, and varying amounts of other minerals.© JonesThese &minerals Bartlett calcify Learning, (harden) LLCthe bone. © Jones & Bartlett Learning, LLC However, bones are not completely stiff and do have Yellow Marrow NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION flexibility. The organic matter is bone cellsosseo ( us cells) mixed with collagen and various protein- carbohydrate complexes. Osseous tissue matures into either compact © Jonesosseous & Bartlett tissue orLearning, spongy osseous LLC tissue (FIGURE 2.3). © Jones & Bartlett Learning, LLC NOT FORCompact SALE osseous OR DISTRIBUTION tissue is dense layers of bone cells NOT FOR SALE OR DISTRIBUTION and collagen. There are no spaces between the layers FIGURE 2.4 Bone Marrow. of compact osseous tissue; however, there are passageways to allow for vascular and nerve supply. Spongy osseous tissue cells. In children, almost all of the bone marrow is red. has the© same Jones composition & Bartlett as compact Learning, LLC © Jones & Bartlett Learning, LLC osseous tissue, but its appearance is different. Spongy In adults, red bone marrow is restricted to the axial NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION osseous tissue develops slivers of tissue that leaves skeleton and the proximal ends of the bones of the spaces somewhat like a honeycomb or lattice-work. appendicular skeleton. The rest of it converts into yel- Yellow bone marrow Also, spongy bone is always encased by a thickness of low bone marrow. is fatty tissue compact bone. and no longer is involved in producing blood cells, but Bone© Jones marrow & isBartlett a soft tissue Learning, that occupies LLC the can revert back© Jonesinto red &bone Bartlett marrow Learning, if some severe LLC spaces NOTof spongy FOR osseous SALE tissue OR andDISTRIBUTION the passageways condition createsNOT a muchFOR greater SALE than OR normal DISTRIBUTION need for of compact osseous tissue (FIGURE 2.4). Bone marrow production. begins as red bone marrow. Red bone marrow plays Bones, like any other organ, need a blood sup- a significant role in producing red and white blood ply and nerve supply. Vascular tissue (blood vessels) includes arteries and veins. Arteries deliver everything © Jones & Bartlett Learning, LLC © Jonesthe cells &of Bartletta bone need. Learning, Veins remove LLC any waste pro- NOT FOR SALE OR DISTRIBUTION NOTduced FOR as wellSALE as take OR away DISTRIBUTION and deliver any cell products produced. For instance, bones play a role in the formation of blood cells which are needed throughout the body and not just in bones. A system of communi- cation is also needed. Nerves pass into bones for this © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC purpose. Examples include, through the nerves of the Compact NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Tissue nervous system, bones can communicate about sensa- tions and the nervous system can communicate to the Spongy bones about producing more or less blood cells. Tissue © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION PAUSE TONOT CHECK FOR FOR SALE UNDERSTANDING OR DISTRIBUTION

1. What are the three main functions of the skeletal system? © Jones & Bartlett Learning, LLC © Jones2. Distinguish & Bartlett between Learning, bone, bone LLC tissue, osseous tissue, and bone cell. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 3. Which part of a bone is involved in blood formation? FIGURE 2.3 Compact and Spongy Osseous Tissue.

© Jones & Bartlett▸▸ Types Learning, of Bones LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION There are four main types of bones (FIGURE 2.5). They are long, short, flat, and irregular. Bones are three- dimensional objects which have height, width, and Sesamoid Bones depth. Most of the bone types are classified accord- ing to the relationships© Jones of these & Bartlett dimensions. Learning, LLC © Jones & Bartlett Learning, LLC Long bonesNOT include FOR the SALE longest OR ones DISTRIBUTION in the NOT FOR SALE OR DISTRIBUTION body, but this is not the reason they are titled this. Rather, it is because their length in relation to their width is much greater. For instance, the femur (thigh© Jones bone) & is Bartlett much longer Learning, than a phalange LLC (digit), © Jones & Bartlett Learning, LLC butNOT both FOR are SALElong bones OR DISTRIBUTIONbecause of the difference NOT FOR SALE OR DISTRIBUTION in their respective lengths and widths. Further- more, the depth and width are relatively similar; Sutures like a cylinder. Short bones, such as the bones in the wrist, are cube-like. Their length, width, and Sutural © Jones & Bartlettdepth are Learning, not necessarily LLC the same, but similar ©(or Jones & Bartlett Learning, LLC Bone NOT FOR SALEclose) OR in length.DISTRIBUTION Flat bones, such as the scapulaNOT FOR SALE OR DISTRIBUTION (shoulder blade), are called this because of its lack of depth in relation to the height and width. The rest of the bones are grouped as irregular bones because there is not a uniform relationship between © Jones & Bartlett Learning, LLCFIGURE 2.6 Example of a Sesamoid© Jones Bone & (top) Bartlett and a SuturalLearning, LLC its dimensions. An example is a vertebra which has a NOT FOR SALE OR DISTRIBUTIONBone (bottom). NOT FOR SALE OR DISTRIBUTION very unusual shape. In addition to the traditional list of bone types are sesamoid and sutural bones (FIGURE 2.6). ▸▸ Long Bone Anatomy Sesamoid bones develop within tendons because of© stress.Jones One & Bartlettexample Learning,that develops LLC in all people Long bones© Jones have several & Bartlett parts that Learning, are important LLC to real- andNOT is theFOR largest SALE sesamoid OR DISTRIBUTION bone is the patella (knee- ize (FIGURENOT 2.7 FOR). The SALE diaphysis OR (shaft) DISTRIBUTION is the cylindrical cap). Most of the others, if they develop, are in the middle region and is composed of compact bone. It has hands and feet. A sutural bone is an extra bone in a hollowed out center called the medullary cavity, the cranium. also known as the marrow cavity because it is filled

Medullary Cavity © Jones & Bartlett Learning, LLC © JonesEndosteum & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FORCompact SALE Bone OR DISTRIBUTION Periosteum

Diaphysis

Distal © Jones & Bartlett Learning, LLC © Jones & BartlettEpiphysis Learning, LLC NOT FOR SALELong ORBone DISTRIBUTIONShort Bone Flat Bone Irregular BoneNOT FOR SALE OR DISTRIBUTION FIGURE 2.5 The Types of Bones. FIGURE 2.7 Lone Bone Anatomy.

© Joneswith & Bartlettbone marrow. Learning, This cavity LLC is lined with a connec- © Jones & Bartlett Learning, LLC tive tissue called the endosteum. The epiphyses TABLE 2.2 Depression Terms NOT FOR SALE OR DISTRIBUTION NOT FOR(singu SALElar – epiphysis OR DISTRIBUTION) are the expanded ends of the bone and they contain spongy bone inside their outer layer of Term Definition compact bone. The very end of each epiphysis is covered by hyaline cartilage that protects it. This tissue is also Alveolus pit or socket Fossa shallow, broad, or elongated basin referred to as articular ©cartilage Jones because& Bartlett it is part Learning, of LLC © Jones & Bartlett Learning, LLC Sulcus groove for a tendon, nerve, or blood a joint (articulation). TheNOT rest FORof the SALEouter layer OR of DISTRIBUTIONbone vessel NOT FOR SALE OR DISTRIBUTION is covered by a collagen tissue called periosteum.

PAUSE TO CHECK FOR UNDERSTANDING © Jones & Bartlett Learning, LLC TABLE 2.3 ©Articulation Jones &Terms Bartlett Learning, LLC 1. ListNOT and describe FOR SALE the four ORtypes DISTRIBUTION of bones. NOT FOR SALE OR DISTRIBUTION Term Definition 2. What is the difference between epiphysis and diaphysis? Condyle round knob 3. Which connective tissue wraps around a long bone? Facet smooth, slightly concave or convex © Jones 4.& BartlettWhich connective Learning, tissue covLLCers the ends of long © Jones & Bartlettsurface Learning, LLC NOT FOR SALEbones? OR DISTRIBUTION NOTHead FOR SALE ORproximal, DISTRIBUTION expanded end of some bones

▸▸ Anatomical Features of Bones © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Whether long, short, flat, or irregular, bones have TABLE 2.4 Passageway Terms features, sometimes calledNOT landmarks. FOR SALE The OR features DISTRIBUTION NOT FOR SALE OR DISTRIBUTION are important because they are sites that other tissue Term Definition either connects to bone or passes through it. The anatomical features of bones have been divided into four Canal tubular, tunnel-like passage main categories:© Jones articulations, & Bartlett projectionsLearning, (sometimes LLC Fissure © Jonesslit & Bartlett Learning, LLC Foramen opening into a canal called extensions), depressions, and passageways. NOT FOR SALE OR DISTRIBUTION Sinus NOTair FOR filled SALEspace OR DISTRIBUTION Projections are convex “bumps” that extend from the main surface of a bone. Depressions are concavi- ties that dip inwardly from the main surface of a bone. Articulations are features of bones related to the struc- PAUSE TO CHECK FOR UNDERSTANDING © Jonesture & Bartlettof a joint. Learning,They can be LLC either concave or convex. © Jones & Bartlett Learning, LLC NOT FORPassageways SALE OR are DISTRIBUTION tunnel-like features that extend into NOT1. FOR List and SALE define OR the DISTRIBUTIONfour categories of bone eatures.f the inner parts of bone or all the way through to the 2. Which category does the feature called head TABLES 2.1–2.4 other side. list and briefly define the sev- belong to? eral terms associated with each category. 3. Which category does the feature called foramen © Jones & Bartlett Learning, LLCbelong to? © Jones & Bartlett Learning, LLC TABLE 2.1 Projection NOTTerms FOR SALE OR DISTRIBUTION4. Which category does the featurNOTe called FOR epicondyle SALE OR DISTRIBUTION belong to? Term Definition 5. Which category does the feature called fossa belong to? Crest© Jones &narrow Bartlett edge Learning, LLC © Jones & Bartlett Learning, LLC EpicondyleNOT FORexpanded SALE regionOR DISTRIBUTION superior to a condyle NOT FOR SALE OR DISTRIBUTION Line slightly raised, elongated ridge Process bony prominence ▸▸ The Skeleton Protuberance bony outgrowth The skeleton is the organization of all the bones Spine sharp, slender narrow process (FIGURE 2.8). The average adult skeleton contains © Jones Trochanter& Bartlett Learning,massive process LLC (only found on femur) © Jones & Bartlett Learning, LLC 206 bones. Like the body regions, the skeleton is divided NOT FORTubercle SALE OR DISTRIBUTIONsmall, rounded process NOT FOR SALE OR DISTRIBUTION Tuberosity rougher than tubercle process into axial and appendicular regions. The axial region includes bones of the skull, the vertebral column, and

FIGURE 2.9 The Joints of the Knee. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FORjoint. SALE Chapter OR 9, DISTRIBUTIONThe Ankle, will describe this in more detail. Interestingly, many body regions that have been called joints are actually a compilation of more than one joint. © Jones & Bartlett Learning, LLC An example is the knee© Jones which is& actuallyBartlett a region Learning, LLC NOT FOR SALE OR DISTRIBUTIONformed by three joints (NOTFIGURE FOR 2.9). They SALE are ORthe articDISTRIBUTION- ulations between 1) the femur and tibia, 2) the patella and femur, and 3) the tibia and fibula.

FIGURE 2.8 The Skeleton. © Jones & Bartlett Learning, LLC Classifications© Jones & of Bartlett Joints Learning, LLC theNOT thoracic FOR cage.SALE The OR appendicular DISTRIBUTION region contains Joints canNOT be classified FOR SALE as either ORfunctionally DISTRIBUTION by their abil- bones in the upper and lower extremities. Chapters 5–7 ity to move or structurally by how the tissues that stabi- synarthroses will be more specifically examine the bones. lize them. Functional classes include 1) which are non-movable, 2) amphiarthroses which are slightly movable, or 3) diarthroses which are freely © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ▸▸ Joints movable. NOT FOR SALE OR DISTRIBUTION NOT FOR SALEThe structural OR DISTRIBUTION joint classifications are bony, The bones of the skeleton are arranged about joints, fibrous, cartilaginous, or synovial (FIGURE 2.10). Bony also known as articulations. A joint is the intersec- joints (synarthrodial) are where two bones have actu- tion between two bones. There is one exception to this ally fused together and appear more like one bone. rule. In the ankle,© three Jones bones & articulateBartlett toLearning, form one LLCFor example, an infant has© Jones two frontal & Bartlett bones, but Learning, this LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Suture Joint

Sternum Bone © Jones & Bartlett Learning,Clavicle LLC Cartilage © Jones & Bartlett Learning, LLC NOT FOR SALE ORFronta DISTRIBUTIONl NOT FOR SALE OR DISTRIBUTION Bone

Fibers Bone © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE ORBony DISTRIBUTION Joint Cartilaginous JointNOT FOR SALEFibrous OR Joint DISTRIBUTION Synovial Joint FIGURE 2.10 Categories of Joints.

articular © Jonesjoint & Bartlettcloses during Learning, maturity LLCand only one bone is left. © Jonesbones articulate, & Bartlett this Learning,cartilage is also LLC called In a fibrous joint, such as the suture joints between cartilage. NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION cranial bones, the bones are connected by thick, Some synovial joints have extra pieces of relatively tough collagen fibers. These types of joints restrict tough, dense cartilage called fibrocartilage to fur- movement to almost nothing (amphiarthrodial). ther protect and absorb forces placed upon it. It also Cartilaginous joints are so called because the two improves the fit and stability of the adjoining bone bones of these joints are© joinedJones by & some Bartlett type of Learning, car- and LLC provides a smooth surface© Jonesfor a bone & Bartlett to rotate Learning, LLC tilage. The cartilage of NOTthese jointFOR types SALE is not OR as DISTRIBUTIONthick across another. FibrocartilageNOT is referred FOR to SALE by differ OR- DISTRIBUTION and strong as the collagen fibers in fibrous joints. ent names depending on the joint such as the meniscus So, movement is more than fibrous joints, but still in the knee. quite restricted (amphiarthrodial). The articulation between© the Jones clavicle & andBartlett the sternum Learning, is an example LLC of Classification© Jones of Synovial & Bartlett Joints Learning, LLC a cartilaginous joint. Synovial joints, like the elbow NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION or knee, allow for great movement (diarthrodial) and There are six classes of joints. They are the ball and socket, because of this require many accessory tissues to sta- hinge, pivot, saddle, condylar (also called ellipsoid), plane bilize them. (also called gliding) joints. Illus trations and examples of each joint classification are in FIGURES 2.12–2.14. With © JonesSynovial & Bartlett Joint Learning, Anatomy LLC © Joneseach class & ofBartlett joints, oneLearning, bone end LLC is convex and the NOT FOR SALE OR DISTRIBUTION NOTother FOR is concave. SALE OR DISTRIBUTION The anatomy of a synovial joint is more complex than Ball and socket joints are joints with one bone the other types of joints (FIGURE 2.11). At the articu- having a spherical head (ball) that articulates with a lation between the bones of a synovial joint is a small relatively deep depression (socket) on the other bone. space called the joint cavity. This cavity is enclosed Hinge joints are similar in appearance to condylar by a joint capsule. The© innerJones liner & ofBartlett this membrane Learning, joints, LLC but have more rounded© endsJones rather & Bartlettthan oval Learning, LLC is the synovial membraneNOT. TheFOR synovial SALE ORmembrane DISTRIBUTION ends that articulate with each NOTother. FOR SALE OR DISTRIBUTION secretes synovial fluid, a slippery lubricant that nour- Pivot joints are so called for the convex end of ishes structures within the joint cavity, rinses waste one bone rotating about its long axis within the con- products from them, and reduces friction which can cave groove of the other bone. The radioulnar joints wear out© theJones joint. & Bartlett Learning, LLC of the elbows© and Jones the atlantoaxial & Bartlett joint Learning, (articulation LLC SynovialNOT FORjoints SALEalso have OR ligaments DISTRIBUTION which are between the NOTfirst twoFOR vertebrae) SALE ORof the DISTRIBUTION neck are the tough, bungy cord-like connective tissue. Ligaments only pivot joints in the body. Saddle joints have span from one bone to another and are the primary such sharp curvatures to their bone ends that they stabilizers as one bone articulates (moves) across the resemble a saddle. other. The ends of all bones are covered by hyaline car- Condyloid joints have corresponding ends that © Jonestilage & Bartlett to protect Learning, and since theseLLC ends are where two © Jonesare more & oval Bartlett rather than Learning, round. With LLC plane joints, the NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Bone

Joint Cartilage

Femur

NOT FOR SALE OR DISTRIBUTION Ulna NOT FOR SALE OR DISTRIBUTION

Hip Elbow FIGURE 2.12 Examples of a Ball and Socket Joint (left) and a Hinge Joint (right). © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION Humerus Radius Ulna

Wrist Bone

Hand Bone © Jones & Bartlett Learning, LLC © JonesLeading to& Bartlett Learning, LLC NOT FOR SALE ORRadius DISTRIBUTION NOT FORThumb SALE OR DISTRIBUTION Ulna

Elbow Thumb

FIGURE 2.13 Examples© Jonesof a Pivot & Joint Bartlett (left) and Learning, a Saddle Joint LLC (right). © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

NOTHand FOR Bone SALE OR DISTRIBUTION NOT FORFoot SALE OR DISTRIBUTION Bone Foot Bone

Finger Bone © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION

Hand Foot FIGURE 2.14 Examples© Jonesof a Condyloid & Bartlett Joint (left) Learning, and a Plane JointLLC (right). © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION bone ends are much flatter and the movement is more of a gliding (or sliding) motion rather than a rotation. PAUSE TO CHECK FOR UNDERSTANDING Synovial joints are also described in terms of their © Jones & Bartlett Learning, LLC 1. What© Jones are the four & Bartletttypes of structural Learning, joints andLLC how ability to move about one or more of the axes of rota- much movement does each one allow? tion.NOT Multi-axial FOR SALE, also OR called DISTRIBUTION tri-axial, joints can move NOT FOR SALE OR DISTRIBUTION 2. List the main structures of a synovial joint and what through all three planes. The only multi-axial joints they do (i.e., a ligament …). are classified as ball and socket. Bi-axial joints are lim- 3. List and briefly describe the six categories of ited to two planes and include condylar, saddle, and synovial joints. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC plane joints. Mon-axial joints only move in one body 4. Distinguish between mon-, bi-, and tri-axial. NOT FOR SALEplane. OR Mon-axial DISTRIBUTION includes hinge and pivot joints. NOT FOR SALE OR DISTRIBUTION