Chapter 8, sections 8.2-8.4

what produces movement at synovial joints

action of skeletal muscle

origin

relatively fixed end of a skeletal muscle

insertion

more movable end of a skeletal muscle

when does movement at a joint occur

when a muscle contracts

what do a muscle’s fibers do

pull the insertion toward the origin

flexion

bending parts of a joint

extension

straightening of parts at a joint

lateral flexion

bending to the side

abduction

moving a part of body away from midline

adduction

moving a part of body toward midline

dorsiflexion

ankle movement which points toes upward

plantar flexion

ankle movement which points toes downward

circumduction

movement in a circular path

rotation

moving around an axis

medial rotation

movement of limb so anterior surface moves toward midline

lateral rotation

movement of limb so anterior surface moves away from midline

supination

forearm rotation so palm faces upward or forward, or lying face up (supine)

pronation

forearm rotation so palm faces downward or backward, or lying face down (prone)

inversion

turning of foot so plantar surface faces midline

eversion

turning of foot so plantar surface faces away from midline

protraction

movement of a body part forward

retraction

movement of a body part backward

elevation

raising a body part

depression

lowering a body part

examples of large, complex synovial (also freely movable) joints

shoulder, elbow, hip, knee

shoulder joint

head of humerus and glenoid cavity of scapula, loose joint capsule

what do the ligaments of the shoulder joint prevent

displacement

shoulder joint makeup

glenoid labrum, several bursae

shoulder joint movement

very wide range, including rotation, circumduction

major ligaments in shoulder joint

coracohumeral, glenohumeral, transverse humeral

articulations of elbow joint

hinge joint and plane (gliding) joint

hinge joint of elbow joint

between trochlea of humerus and trochlear notch of ulna (flexion/extension only)

plane joint of elbow joint

between capitulum of humerus and fovea on head of radius ( pronation/supination)

plane joint of elbow joint makeup

several reinforcing ligaments

major ligaments of elbow joint

radial collateral, ulnar collateral, anular

hip joint

head of femur and acetabulum of hip bone

hip joint makeup

acetabular labrum, heavy joint capsule, many reinforcing ligaments

movement of hip joint

variety of movements, yet less than at shoulder joint

major ligaments of the hip joint

Iliofemoral, pubofemoral, Ischiofemoral

what is the strongest ligament in body

Iliofemoral ligament

knee joint

cushioned by bursae, fat pads, menisci separate femur and tibia, modified hinge joint between condyles of femur and tibia, plane joint between femur and patella

knee joint movements

flexion/extension, and some rotation when knee is flexed

what is the largest and most complex synovial joint

knee joint

3 bones of knee joint

femur, tibia, patella

femur in knee joint

medial and lateral condyles of distal end

tibia in knee joint

medial and lateral condyles of proximal end

patella in knee joint

articulates with anterior surface of femur

what do joint injuries result from

trauma, overuse, infection, inappropriate immune attack, degeneration

arthroscopy

used to treat shoulder, elbow, knee injuries, and can be used to diagnose certain conditions

dislocations

displacement of articulating surfaces, common in shoulder, knee, fingers, jaw

sprain

tearing of connective tissue in joint, without bone dislocation

torn ligament

result from twist, overextension, lifting heavy object, or fall

bursitis

inflammation of a bursa, from overuse or stress

arthritis

inflammation, swelling, and pain in a joint

rheumatoid arthritis

autoimmune disease

osteoarthritis

degenerative, most common types, occurs with aging

lyme arthritis

caused by lyme disease, passed through tick bite

what is first to change with age in joints

fibrous joints; can strengthen, however, over a lifetime

what can keep joints functional longer

activity and exercise