Unit 2 Concept 2: Joints and Skeletal Movement

Vocabulary flashcards covering the functional and structural classification of joints, types of synovial joints, body movements, and muscle contraction principles.

Joints (Articulations)

The meeting place between two or more bones that give the skeleton mobility and hold it together.

Ligaments

Important connective tissues that connect bone to bone.

Tendons

Important connective tissues that connect muscles to bones.

Synarthroses

Non-moving joints, such as the cranium (part of the skull that protects the brain).

Amphiarthroses

Slightly moving joints, such as where pubis bones meet in the pelvis.

Diarthroses

Freely moving joints, such as knee and elbow joints; all synovial joints fall into this category.

Fibrous Joints

Joints that connect bones with the collagen fibers of dense connective tissue and are mostly immovable.

Sutures

Fibrous joints that hold together bones in the skull.

Syndesmosis

Fibrous joints where bones are held together by ligaments only, such as the fibula and tibia in the lower leg.

Gomphoses

Fibrous joints where teeth are embedded in their sockets.

Cartilaginous Joints

Joints that connect bones to cartilage; can be rigid but also slightly movable.

Synchondrosis

An immovable cartilaginous joint made of a bar or plate of hyaline cartilage between the sternum and the first rib.

Symphysis

A slightly movable cartilaginous joint made of fibrocartilaginous intervertebral discs that act as shock absorbers between vertebrae.

Synovial Joints

Joints that connect bones with dense connective tissues and a fluid-filled joint cavity, allowing them to be freely movable.

Articular Cartilage

A feature of synovial joints that covers the opposing bone surfaces.

Synovial Fluid

Fluid in the joint cavity that acts as a lubricant.

Synovial Joint Diagram

A structural diagram showing periosteum, spongy bone, compact bone, ligament, synovial membrane, joint cavity, articular cartilage, joint capsule, and yellow bone.

Gliding Joint

Also known as a plane joint; allows gliding movements when one flat bone surface glides or slips over another back and forth or side to side (e.g., intercarpal joints in wrists and intertarsal joints in ankle).

Hinge Joint

Joint that only moves in one direction like a door hinge, allowing angular movements like flexion and extension (e.g., elbow and interphalangeal finger joints).

Flexion

Bending in a way that decreases the angle of the joint so the articulating bones get closer.

Extension

The reverse of flexion; going beyond anatomical position is called hyperextension.

Pivot Joint

Joint that allows rotation as well as twisting movements back and forth (e.g., where humerus meets radius and ulna at the elbow).

Supination

Turning or twisting backward.

Pronation

Turning or twisting forward.

Condylar Joint

Joint shaped like a pedestal with a joint on top that allows movements like flexion, extension, abduction, and adduction (e.g., in the wrist).

Abduction

Moving a limb away from the median plane along the frontal plane.

Adduction

Moving toward the median plane, opposite of abduction.

Saddle Joint

Joint that allows opposition movements (thumb to finger) as well as flexion, extension, abduction, and adduction (e.g., thumb joints).

Ball & Socket Joint

Joint with lots of maneuverability that allows rotational movements, abduction, adduction, flexion, and extension (e.g., shoulder and hip joints).

Rotation

Turning of the bone around its own long axis.

Circumduction

Moving a limb in a circle (e.g., making circles with arms).

Elevation and Depression

Lifting a body part superiorly (elevation) and then lowering it (depression) (e.g., shrugging shoulders, then dropping them).

Protraction and Retraction

Sticking a body part out (protraction) and pulling it back in (retraction) (e.g., sticking jaw out to make an underbite, then pulling back in).

Dorsiflexion and Plantar Flexion

Lifting the foot up (dorsiflexion) and down (plantar flexion) at the ankle.

Inversion and Eversion

Turning the foot inward to be pigeon-toed (inversion) or outward (eversion).

Isotonic Contraction

A main type of muscle contraction that causes a change in the length of muscles (e.g., lifting a box or doing push-ups).

Isometric Contraction

A main type of muscle contraction with no change in muscle length (e.g., standing with good posture or holding a plank).

Insertion

The movable bone during a muscle contraction (e.g., in a bicep curl, the radius is the insertion point and pulls towards the scapula).

Origin

The bone that moves less or not at all during a muscle contraction (e.g., in a bicep curl, the scapula is the origin).