Joints

Joint

A point where two or more bones meet, allowing for movement and protecting bones from grinding together.

Cartilage

A smooth, elastic tissue that covers the ends of bones, acting as a shock absorber and reducing friction.

Ligaments

Strong, fibrous bands that connect bone to bone, providing stability and preventing improper movement.

Tendons

Fibrous tissue that connects muscle to bone, enabling the muscle to create movement by pulling on the bone.

Synovial Fluid

A lubricant in synovial joints that ensures smooth movement, similar to motor oil.

Joint Capsule

A sleeve-like structure around the joint that holds synovial fluid in place.

Fibrous Joints

Immovable joints fused by connective tissue, designed for protection (e.g., sutures of the skull).

Cartilaginous Joints

Slightly movable joints connected by cartilage pads, allowing for limited movement (e.g., between vertebrae).

Synovial Joints

Freely movable joints allowing a wide range of motion, with six types including ball and socket and hinge.

Flexion

Decreasing the angle between two bones, such as bending the leg at the knee.

Extension

Increasing the angle between two bones, such as straightening the arm.

Abduction

Moving a body part away from the midline of the body, like lifting an arm to the side.

Adduction

Moving a body part toward the midline of the body, like bringing an arm back down.

Rotation

Turning a bone around its own long axis, like turning your head left or right.

Circumduction

A circular movement combining flexion, extension, abduction, and adduction.

Dorsiflexion

Pulling your toes up toward your shin.

Plantarflexion

Pointing your toes downward.

Inversion

Turning the sole of the foot inward.

Eversion

Turning the sole of the foot outward.

Ball and Socket Joint

A joint type allowing movement in almost every direction (e.g., shoulder, hip).

Hinge Joint

A joint type allowing movement in one plane, like the elbow or knee.

Pivot Joint

A joint that allows for rotation only, such as the top of the neck.

Gliding Joint

Joints where flat bones slide over each other, like in the wrist or ankle.

Saddle Joint

A joint allowing movement back and forth and side to side, like at the base of the thumb.

Condyloid Joint

Similar to a ball and socket joint but without full rotation, such as at the wrist.

Pronation

Turning the palm downward during a specific movement, such as in a tennis forehand.

Supination

Turning the palm upward during a specific movement, such as in ten-pin bowling.