2 Joints A. Articulations: functional junctions btwn bones B. enable a wide variety of body movementsC. classified according to the degree of movementimmovableslightly movablefreely movableD. can also be classified by type of tissueFibrous JointsCartilaginous JointsSynovial Joints
4 E. Fibrous Joints held close together by dense connective tissue are immovable (sutures of skull) or slightly movable (joint btwn distal tibia & fibula)
5 F. Cartilaginous Joints 1. Hyaline cartilage or disks of fibrocartilageunite the bones2. Intervertebral disks btwn vertebrae help absorb shock & are slightly movable3. ex: symphysis pubis, first rib w/ the sternum
6 G. Synovial Joints1. Most joints of the skeleton, are complex2. Articular ends are covered w/ hyaline cartilage3. A joint capsule consists of an outer layer of dense connective tissue that joins the periosteum & an inner layer made up of synovial membranea. Synovial fluid lubricates4. Some contain shock-absorbing pads fibrocartilage called menisci5. Some have fluid-filled sacs called bursae
8 6. Based on the shapes of their parts & movements they permit, synovial joints can be classified as: a. Ball & Socket consists of a bone w/ a globular head articulating w/ the cup-shaped cavity of another bone; a very wide range of motion. ex. the hipb. Condyloid consists of an ovoid condyle fitting into an elliptical cavity, permitting a variety of motions; ex. the joint btwn a metacarpal & a phalangec. Gliding occur where articulating surfaces are nearly flat or slightly curved, allowing a back-&-forth motion; ex. wrist, ankle, & btwn vertebrae
9 d. Hinge a convex surface fits into a concave surface movement is in one plane onlyex. elbow & phalange jointse. Pivot a cylindrical surface rotates in a ring of bone & fibrous tissue;ex. joint btwn proximal ends of radius & ulnaf. Saddle forms where articulating surfaces have both concave & convex areas, wide range of movementsex. joint btwn trapezium & metacarpal of thumb
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