Ch 9Joints- Articulations

-between bones, cartilage and bones, or teeth and bones

Functional Classification

•1. Immovable / •2. Slightly movable /•3. Freely movable /

Structural Classification

1. Fibrous – many collagenous fibers

Examples:

a. - ligament can be twisted, amphiarthroticex: distal ends of tibia & fibula

b. - between flat bones, synarthrotic

ex: skull

c. - cone-shaped bony process meets bony socket, synarthrotic

ex: root of tooth

Structural Classification

2. Cartilaginous- cartilage connects Examples:

a. - hyaline or costal cartilageex: b/w 1st ribs & sternumepiphyseal disk – no movement after age 25

(synarthrotic)

b. - broad flat disk of fibrocartilage, amphiarthrotic

ex: pubic symphysis, intervertebral disks

3. Synovial- allow free movements *most joints fit this classification

Examples:a. movement in all planes ex: hip, shoulder

b. - condyle of one bone fits into cavity of another

ex: metacarpals into phalanges

c. - back and forth motion, nearly flat ex: wrist and ankle

d. - convex surface of one bone fits into the concave surface of another

ex: elbow and knee

e. - ex: head side to side, between radius and ulna

f. - between bones that fit togetherex: carpals and metacarpals

Accessory Structures

Ligaments-

Tendons-

Bursae- BursitisBunion

Menisci-

Fat pads -

Preventing injury = limiting range of motion/stabilizing joint• Factors responsible for limiting ROM:

If movement occurs beyond ROM = damage•

• ligaments with some torn collagen fibers• Ligament as a whole survives and joint is not damaged

• • Articulating surfaces forced out of position• Damages articular cartilage, ligaments, joint capsule

• : partial dislocation

9-3 Joint Movement

• Refer to chart from outline

Intervertebral Discs• Separate vertebrae, pads of fibrocartilage• Not found

• nucleus pulposus distort the annulus fibrosus, forcing it into vertebral canal• nucleus pulposus breaks through

the annulus fibrosus, distorts/compresses sensory nerves

Parts of a synovial joint

1. Articular Cartilage-

2. Joint capsule-

3. Joint cavity-

4. Ligaments-

MCL-medial

LCL- lateral

Aging• • A pain and stiffness of skeletal and muscular systems• Several major forms

• • All forms of rheumatism that damage articular cartilages of synovial joints• Damage results from: Infection, Injury to joint, Metabolic problems, Severe

physical stressesOsteoarthritis Caused by:

• wear & tear of joint surfaces• Genetic factors affecting collagen formationGenerally affects people 60 or older

Rheumatoid arthritis Inflammatory conditionCaused by:• Infection• Allergy• Autoimmune disease: body attacks own tissues

Gouty arthritis Buildup of uric acid crystals in synovial fluid interferes w/ joint movementCaused by:• Gout• Calcification of joints in people over 85