A & P - Chapter 7 - Joints*

Synovial Joints

Joints that are held together by a joint capsule and ligaments and are most associated with movement in the body.

Planar (gliding) Joint

Composed of the articulation between two relatively flat bony surfaces. Limited amount of motion. (ex. interracial joints of hand)

Hinge Joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane.

Pivot Joint

joint that allows the rotation of one bone around another bone

Condyloid Joint

Egg-shaped end of one bone that fits into an oval cavity of another, movement - side to side and back & forth.

Saddle Joint

type of joint found at the base of each thumb; allows grasping and rotation

Ball and Socket Joint

A ball and socket joint allows for radial movement in almost all directions. They are found in the hips and shoulders. (Like a door knob)

Rheumatoid arthritis

This autoimmune disorder affects tissue on joint surfaces.

Diarthrosis

Freely movable, stable, complex, always synovial joint, hip/shoulder have labrum

Synarthrosis

Immovable, Ex: sutures & synchondroses

Fibrous Joints

No synovial cavity, connected by dense fibrous CT, Ex: sutures, syndesmoses & gomphoses

Cartilaginous Joints

No synovial cavity, cartilage binds articulating bone (fibrocartilage or hyaline), are synarthrosis or amphiarthrosis, ex: synchondroses and symphyses

Gomphosis

Immovable, ligament (periodontal ligament) holds teeth in bony socket.

Amphiarthrosis

Slightly movable Ex: symphyses & syndesmoses

Synovial Joint Features

(1.) Joint capsule with 2 layers (2.) Joint cavity inside of joint capsule (3.) Synovial membrane (inner layer of capsule) (4.) Synovial fluid forms film over joint surface (5.) Articular cartilage covers joint surface (6.) Articulating Bone (bones that make up the joint

Joint Capsule

has 2 layers, thickness varies in body, may be reinforced by or incorporate tendons and ligaments

Synovial Fluid

Clear, yellow, viscous, reduces friction between articulations, provides nourishment for articular cartilage, contains hyaluronic acid and lubricin

Articular Cartilage

Lacks blood vessels & nerve, transmits and distributes high loads, maintenance of contact stress at low levels, reduces friction, shock absorber

Menisci

Made of fibrocartilage, allows articular bones to fit tightly together, increases knee stability (increases curve of tibial condyles), reduces friction, shock absorber

Bursae

Flat, sacs, filled with synovial fluid, located between 2 structures (skin/bone, tendon/bone, muscle/bone, ligament/bone)

Types of Diarthroses

Gliding (plane), hinge, pivot, condyloid, saddle, ball and socket

Examples of Gliding (planar) Joint

intercarpal/intertarsal joints, sternoclavicular joint, vertebrocostal joints, articular processes of adjacent vertebrae

Examples of Hinge Joint

Knee, elbow, ankle, interphalangeal joints

Examples of Pivot Joint

Proximal radioulnar joint (supination, pronation), Atlanto-Axial joint (turning head side to side "no")

Examples of Condyoid Joint

Wrist (raduis, scaphoid/lunate) and metacarpophalangeal joints for digits 2-5

Examples of Saddle Joint

joint between trapezium and metacarpal of thumb

Examples of Ball and Socket Joint

Shoulder and hip joints

Flexion

Decreasing joint angle

Extension

Increasing joint angle

Hyperextension

More than normal anatomical extension

Supination

Palm is turned anteriorly

Pronation

Palm is turned posteriorly

Circumduction

Movement in a circle

Abduction

Movement away from the midline

Adduction

Movement toward the midline

Opposition

Movement of the thumb across the palm to touch the fingertips on same hand

Osteoarthritis

What degenerative joint disease causes the flaking of cartilage that exposes underlying bone, is generally non-inflammatory and produces bone spurs (osteophytes)

Strain

What is a less serious injury, an overstretched or partially torn muscle?

Sprain

What is the twisting of joint that stretches or tears ligaments, no dislocation, damage to nearby blood vessels (swelling & hemorrage), muscles & tendons?

Elevation

upward movement of a body part

Depression

downward movement of a body part

Protraction

Moving a part forward

Retraction

moving a part backward

Inversion

sole of foot inward

Eversion

sole of foot outward

Dorisflexion

bends the foot upward at the ankle, toes up

Plantar Flexion

bends the foot downward at the ankle, toes down