JOINTS AND JOINT

MOVEMENTHuman A&P

JOINTS With the exception of the hyoid bone,

every bone in the body forms a joint with at least one other bone

Joints serve two functionsHold the bones securely togetherGive the rigid skeleton flexibility

JOINT CLASSIFICATION Functional: depends on the amount of

movement allowed by the joint Structural: depends on whether fibrous

tissue, cartilage, or a joint cavity separates the bony regions at the joint

THREE TYPES OF JOINTS Synarthrosis Joints – held together by

collagenous fibers. The bones closely contact each other. Ex. Skull sutures, distal end of fibula and tibia

Amphiarthosis Joints – hyaline cartilage or fibrocartilage connect the bones. Ex. Vertebrae, pubis bone

Diarthrosis (Synovial Joint) – Most common joint and most complex

SYNOVIAL JOINT

TYPES OF SYNOVIAL JOINTS

BALL AND SOCKET JOINT Hip and shoulder are

examples Egg shaped head

with a cup shaped cavity

CONDYLOID JOINT Metacarpals and

phalanges

GLIDING JOINT Joints of the wrist

and ankle Back and forth

movement

HINGE JOINT Elbow Concave and convex

surfaces fit together

PIVOT JOINT Rotation around a

central axis Radius and ulna,

neck turning

SADDLE JOINT Carpal and

metacarpal of the thumb

INFLAMMATORY DISORDERS OF THE JOINTS Bursitis:

inflammation of bursa (synovial membrane); water on the knee

INFLAMMATORY DISORDERS OF THE JOINTS Sprain

Ligaments or tendons reinforcing joint are damaged by excessive stretching or are torn away from bone

Slow to heal because of poor blood supply Dislocation

When a bone is forced out of normal position in the joint cavity

INFLAMMATORY DISORDERS OF THE JOINTS Arthritis

Most widespread, crippling disease in the U.S.

1 in 7 Americans suffer with it Initial symptoms: Pain, stiffness, and

swelling of the jointAcute and Chronic Forms of Arthritis

INFLAMMATORY DISORDERS OF THE JOINTS Acute Arthritis

Result from bacterial invasionTreated with antibioticSynovial membrane thickens and fluid

production decreases, leading to increased friction and pain

INFLAMMATORY DISORDERS OF THE JOINTS

Chronic Arthritis Osteoarthritis

Most common form Degenerative condition usu. affects the aged Wear and tear affects Can cause bone spurs which restrict joint movement

Rheumatoid arthritis Occurs between 40-50 years old, but can occur at any age Affects more women than men Many joints affected at the same time and usu. in

symmetrical manner (left elbow than right elbow) Marked by remission (goes away) and flare ups (comes

back) Autoimmune disease – body attacks its own tissues

Gouty arthritis

INFLAMMATORY DISORDERS OF THE JOINTS