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JointsJointsJointsJoints

Chapter 7

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JointsJointsJointsJoints

• Places where bones meet• Classified structurally by

anatomy• Classified structurally by motion

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Structural ClassificationStructural ClassificationStructural ClassificationStructural Classification

• Based on material between bones• Fibrous joints- no cavity just

fiberous Connective tissue• Cartilaginous joints- bones held

together by cartilage• Synovial joints- have synovial

cavity and dense irregular tissue of articular capsule and often ligaments

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Functional JointsFunctional JointsFunctional JointsFunctional Joints

• Synarthrosis- immoveablepelvis , sutures,, teeth

• Amphiarthrosis- slight movementEpiphysis, tibia-fibula, vertebrae and pelvic

symphysis

• Diarthroses- free movement= synovialdefined by movement

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Fibrous JointsFibrous JointsFibrous JointsFibrous Joints

• Little or no movement•Suture- e.g. skull (synarthrosis)

joined by thin layer of dense fibrous connective tissue

•Syndesmosis- e.g.tibia & fibula= amphiarthrosisGreater distance and amount of dense fibrous

material

•Gomphosis- e.g. tooth root in socket = synarthrosis

Figure 7.1aFigure 7.1a

Figure 7.1bFigure 7.1b

Figure 7.1cFigure 7.1c

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Cartilaginous jointCartilaginous jointCartilaginous jointCartilaginous joint

• Synchondrosis- hyaline cartilage

• E.g epiphyseal plate = synarthrosis

• Symphysis- fibrocartilage join• E.g. pubic symphysis and

intervertebral joints = amphiarthrosis

Figure 7.2aFigure 7.2a

Figure 7.2bFigure 7.2b

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Synovial JointsSynovial JointsSynovial JointsSynovial Joints

• Synovial cavity• Articular cartilage• Articular capsule-

Inner layer = synovial secretory membrane

• Synovial fluid• Ligaments• Some contain menisci

Figure 7.3Figure 7.3

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BursaeBursaeBursaeBursae

• Located where friction can occur• E.g. between skin & bone or

bone & tendons, ligaments or other bones

• Structurally similar to joint capsules- Contain synovial membrane and fluid.

Figure 7.10aFigure 7.10a

Figure 7.10bFigure 7.10b

Figure 7.10cFigure 7.10c

Figure 7.10dFigure 7.10d

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Types of motions at Types of motions at synovial jointssynovial joints

Types of motions at Types of motions at synovial jointssynovial joints

• Gliding- flat bone surfaces moving across each other

• Flexion- decrease in angle between articulating

bones

• Extension- Increase in angle between articulating bones

• HyperextensionBending beyond 180o degrees e.g. moving

humerus backwards behind anatomical position

Figure 7.4aFigure 7.4a

Figure 7.4bFigure 7.4b

Figure 7.4cFigure 7.4c

Figure 7.4dFigure 7.4d

Figure 7.4eFigure 7.4e

Figure 7.4fFigure 7.4f

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Motion (cont.)Motion (cont.)Motion (cont.)Motion (cont.)

• Abduction-Movement of bone away from midline

• Adduction-Movement of bone toward midline

• Circumduction-Movement of distal end in a circle

• Rotation-Bone revolves around its own longitudinal

axis

Figure 7.5aFigure 7.5a

Figure 7.5bFigure 7.5b

Figure 7.5cFigure 7.5c

Figure 7.6aFigure 7.6a

Figure 7.6bFigure 7.6b

Figure 7.7aFigure 7.7a

Figure 7.7bFigure 7.7b

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Special MovementsSpecial MovementsSpecial MovementsSpecial Movements

•Elevation- lift upward•Depression- downward

movement•Protraction – movement

forward•Retraction- movement back to

anatomical position

Figure 7.8abFigure 7.8ab

Figure 7.8cdFigure 7.8cd

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Special Movements Special Movements (cont.)(cont.)

Special Movements Special Movements (cont.)(cont.)

• Inversion- move of soles medially

•Eversion- move soles laterally•Dorsiflexion- bending of foot

toward dorsum•Plantar flexion- bend foot

toward plantar surface

Figure 7.8efFigure 7.8ef

Figure 7.8gFigure 7.8g

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Special Movements Special Movements (cont.)(cont.)

Special Movements Special Movements (cont.)(cont.)

•Supination- movement of forearm so palms face forward or upward

• Pronation- movement of forearm so palms face backward or downward

Figure 7.8hFigure 7.8h

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Types of Synovial JointsTypes of Synovial JointsTypes of Synovial JointsTypes of Synovial Joints

• Planar joints- articulating surfaces flat or slightly curved

• Hinge joints- convex to concave surfaceOnly do flexion and extension

• Pivot joints- rounded surface with ring formed by bone and ligamente.g. atlantoaxial joint

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Types of Synovial JointsTypes of Synovial JointsTypes of Synovial JointsTypes of Synovial Joints

•Condyloid joints- convex oval surface to concave oval surfacee.g. wrist & metacarpophyangeal joints

•Saddle joints- one side saddle shaped other sits astride it

•Ball & socket joints- ball like surface into cup like socket surfaceCan do flexion/extension, adduction/adduction

& rotation

Figure 7.9aFigure 7.9a

Figure 7.9bFigure 7.9b

Figure 7.9cFigure 7.9c

Figure 7.9dFigure 7.9d

Figure 7.9eFigure 7.9e

Figure 7.9fFigure 7.9f

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Aging of JointsAging of JointsAging of JointsAging of Joints

• Slowing of synovial fluid production

• Thinning of articular cartilage• Ligaments shorten and lose

flexibility• Influenced by genetic factors