iCEV Slides - The Skeletal System: Joints and Movement

Flashcards and fill-in-the-blanks from iCEV's course on the skeletal system.

Joints

Also known as articulations, these are where two bones come together to support body movement

Joint functional classifications

Synarthrosis, amphiarthrosis, and diarthrosis

Synarthrosis

Joints that are nearly immobile, such as the sutures of the skull

Amphiarthrosis

Joints that provide limited mobility, such as the pubic symphysis of the pelvis

Diarthrosis

Joints that provide the greatest range of motion and are the most common, such as the elbow, shoulder, or ankle

Joint structural classifications

Fibrous, cartilaginous, and synovial joints

Fibrous joints

Joints joining bones by fibrous connective tissue, most commonly synarthroses (immovable)

Cartilaginous joints

Joints joining bones by hyaline cartilage or fibrocartilage; are mainly amphiarthroses (somewhat movable)

Synovial joints

Joints joining bones through a joint cavity with synovial fluid; are most common diarthroses (very movable)

Flexion

The decrease of the angle between two bones of a joint

Extension

The increase of the angle between two bones of a joint

Adduction

Movement towards the body’s midline

Abduction

Movement away from the body’s midline

Circumduction

Movement of a limb in a circle (circumference)

Rotation

The movement of a limb around an axis (turn arm)

Inversion

The tilting of the foot towards the midline

Eversion

The tilting of the foot away from the midline

Synovial joint classifications

Can be further divded based on movement, such as:

• ball and socket joint

• pivot joint

• hinge joint

• saddle joint

• plane joint

• condyloid (ellipsoid) joint

Ball-and-socket joints

Rounded surface of a bone within a depression in another bone, allowing for the most movement in all axes; includes the shoulder and hip

Pivot joints

Rounded portion of a bone enclosed in a ring shape of another bone held in place by a ligament; allows rotational movement in the neck and radius and ulna

Hinge joints

Formed by a convex edge of one bone fitting into a concave edge of another like a door hinge along one axis; allows for flexion and extension in the elbow, knee, and ankle

Saddle joints

Formed by two joints with concave and convex regions, forming a saddle shape allowing flexion, extension, abduction, and adduction in the thumbs and inner ears

Plane joints

Formed by two flat sliding bones allowing for inversion, eversion, flexion, and extension in the vertebrae, metacarpals, and metatarsals

Condyloid joints

Also called ellipsoid joints, they are formed by egg-shaped bones in a similarly shaped socket allowing for flexion, extension, abduction, and adduction in the wrist, knuckles, and jaw