Joints of the Skeletal System Chapter 8 8-1

Chapter 8 Joints of the Skeletal System Joints/Articulations Junctions between bones Ligaments connect bone to bone Functions Bind parts of skeletal system together Enable body to move in response to skeletal muscle contraction Make bone growth possible Permit parts of the skeleton to change shape during childbirth 8-2

Classification of Joints Joint Composition Classification Fibrous Joints dense connective tissues connect bones between bones in close contact Movement Classification synarthrotic immovable amphiarthrotic slightly movable diarthrotic freely movable Cartilaginous Joints hyaline cartilage or fibrocartilage connect bones Synovial Joints most complex Contains synovial fluid allow free movement 8-3

Fibrous Joints 3 Types Syndesmosis Suture Gomphosis Syndesmosis long fibers connect bones amphiarthrotic distal ends of tibia and fibula 8-4

Fibrous Joints Suture between flat bones synarthrotic thin layer of connective tissue connects bones Gomphosis cone-shaped bony process in a socket tooth in jawbone synarthrotic 8-5

Cartilaginous Joints 2 Types Synchondrosis Symphysis Synchondrosis bands of hyaline cartilage unite bones between manubrium and first rib amphiarthrotic 8-6

Cartilaginous Joints Symphysis pad of fibrocartilage between bones pubis symphysis joint between bodies of vertebrae amphiarthrotic 8-7

Synovial Joints diarthrotic joint capsule joint cavity synovial fluid lubrication synovial membrane bursae fluid filled sac Cushions/aids movement of tendons over things 8-8

Types of Synovial Joints Condyloid Joint moves up/down & left/right between metacarpals and phalanges Ball-and-Socket Joint moves in all directions hip shoulder 8-9

Types of Synovial Joints Gliding Joint sliding or twisting between carpals between tarsals Hinge Joint flex/extend elbow between phalanges 8-10

Types of Synovial Joints Pivot Joint rotation between proximal ends of radius and ulna atlas and axis Saddle Joint back/forth, side/side between carpal and metacarpal of thumb 8-11

Types of Joint Movements abduction/adduction dorsiflexion/plantarflexion flexion/extension/hyperextension 8-12

Types of Joint Movements rotation/circumduction supination/pronation 8-13

Types of Joint Movements eversion/inversion protraction/retraction elevation/depression 8-14

Shoulder Joint ball-and-socket head of humerus glenoid cavity of scapula loose joint capsule bursae ligaments prevent displacement very wide range of movement 8-15

Shoulder Joint 8-16

Elbow Joint hinge joint gliding joint pivot joint trochlea of humerus trochlear notch of ulna gliding joint capitulum of humerus head of radius pivot joint radius, ulna flexion and extension, rotation many reinforcing ligaments stable joint 8-17

Elbow Joint 8-18

Hip Joint ball-and-socket joint head of femur acetabulum heavy joint capsule many reinforcing ligaments less freedom of movement than shoulder joint 8-19

Hip Joint 8-20

Knee Joint largest joint most complex modified hinge joint menisci separate femur and tibia medial and lateral condyles of distal end of femur medial and lateral condyles of proximal end of tibia femur articulates anteriorly with patella flexion/extension/little rotation strengthened by many ligaments and tendons bursae 8-21

Knee Joint 8-22

Life-Span Changes Joint stiffness is an early sign of aging Regular exercise can prevent stiffness Changes in symphysis joints of vertebral column diminish flexibility and decrease height Synovial joints lose elasticity 8-23

Sprains damage to cartilage, ligaments, or tendons associated with joints forceful twisting of joint

Bursitis inflammation of a bursa overuse of a joint

Arthritis inflamed, swollen, painful joints Rheumatoid Arthritis Osteoarthritis Gout

Dislocation bones are no longer in their normal position joint capsule and ligaments tear may be nerve damage