Joints of the bodyClassification and mobility

Fibrous- no joint cavity, joined by fibrous tissue, mobility depends on the length of the tissue, most are immovable

Cartilaginous- lack a cavity and bones are joined by cartilage which allows for compression and resilience but not mobility

Synovial – fluid containing joint cavity, freedom of movement, majority of joints

Classification: 3 classes

Suture◦ Bones connected by short fibers◦ Immovable◦ Found in the skull

Syndesmosis◦ Bones connected by longer fibers, ligaments◦ Ex. The connection of the tibia and fibia, immovable◦ Ex. The connection of the radius and ulna slightly

movable allowing for rotation Gomphoses

◦ Periodontal ligament◦ Connects the tooth to the bony alveolar socket◦ Immovable as if “hammered in”

Fibrous

Synchondroses◦ A plate of hyaline cartilage unites the two bones◦ Joint between the growth plate of long bones and

the mature bone, seen in children◦ Joint between the first rib and the manubrium of

the sternum Symphyses

◦ The hyaline cartilage at the end of the bone is connected to a pad of fibrocartilage which is more compressible and resilient, allowing the joint to absorb shock and be flexible

◦ Intervertebral joints and the pubic symphysis of the pelvic bone

Cartilaginous

Same general structure Types: plane, hinge, pivot, condyloid,

saddle, ball and socket Freely movable, depends on design

Bursae and Tendon Sheaths◦ Assist with flexibility of the joint◦ Bursae are fluid filled sacs that line the area

where ligaments, muscles, skin, tendons, and bones rub together.

Synovial joints

General structure

a. Plane b. Hinge c. Pivot d. Condyloid e. Saddle f. Ball and

socket

Types of Synovial joints

Every skeletal muscle is attached in no less than two points.◦ Muscle origin is attached to an immovable bone◦ Muscle insertion is attached to a movable bone

Movement occurs when muscles contract across a joint

Described by the direction in relation to the axis: nonaxial, uniaxial, biaxial, multiaxial

Movement

Gliding- simple back-and-forth, and side to side◦ Include the tarsal and carpal◦ Include the vertebra◦ And is incorporated into other movements

Angular- increase or decrease the angle between two bones◦ Movement of limb by flexion, extension,

abduction, adduction, circumduction Rotation- turning a bone on its axis

◦ Include hip and shoulder◦ Include the 1st two cervical vertebrae

Three types of movement

Common Joint Injuries Sprain- ligaments stretched or torn Cartilage injuries- can not heal must be

removed or joints can get locked up Dislocations- bones are forced out of alignment

Inflammatory and Degenerative ConditionsBursistis- inflammation of the bursaTendonitis- inflamation of tendon sheathsOsteoarthritis and Rheumatoid ArthritisGout Arthritis- high uric acid levels accumulate

and inflame the joints