Joints and Movement Study Guide

Articulation

The connection between two bones that forms a joint, allowing for movement and providing stability to the skeletal system.

Joint Classification

Joints are classified based on their structure (types of connective tissues) and function (degree of mobility).

Structural Classification

The categorization of joints based on their connective tissue structure, affecting stability and range of motion.

Fibrous Joints

Joints connected by fibrous tissue, including sutures, syndesmoses, and gomphoses.

Cartilaginous Joints

Joints connected by cartilage, including synchondroses and symphyses.

Synovial Joints

Freely movable joints characterized by a joint cavity, allowing a wide range of motion.

Synarthrosis

Immovable joints, such as sutures and gomphoses.

Amphiarthrosis

Slightly movable joints, such as syndesmoses and symphyses.

Diarthrosis

Freely movable joints, including hinge, pivot, condyloid, gliding, saddle, and ball-and-socket joints.

Articular Cartilage

Smooth tissue covering the ends of bones in a synovial joint.

Synovial Membrane

Lines the joint capsule and secretes synovial fluid.

Articular Capsule

The two-layered structure surrounding a synovial joint, consisting of an outer fibrous layer and an inner synovial membrane.

Joint Cavity

The space within a synovial joint filled with synovial fluid.

Bursa

A fluid-filled sac that reduces friction in a joint.

Anterior Cruciate Ligament (ACL)

A ligament that stabilizes the knee joint.

Posterior Cruciate Ligament (PCL)

Another ligament that stabilizes the knee joint.

Meniscus

Cartilage in the knee that cushions and stabilizes the joint.

Tibial Collateral Ligament

Provides medial stability to the knee.

Fibular Collateral Ligament

Provides lateral stability to the knee.

Patellar Ligament

Connects the patella to the tibia.

Quadriceps Femoris Muscle

Muscle whose tendon extends the knee.

Flexion

Decreasing the angle between bones (e.g., bending the elbow).

Extension

Increasing the angle between bones (e.g., straightening the elbow).

Abduction

Moving a limb away from the midline (e.g., lifting the arm).

Adduction

Moving a limb towards the midline (e.g., lowering the arm).

Rotation

Turning around an axis (e.g., turning the head).

Circumduction

Circular movement combining flexion, extension, abduction, and adduction (e.g., arm circles).

Elevation

Moving structures superiorly (e.g., shoulder shrug).

Depression

Moving structures inferiorly.

Pronation

Rotating the forearm to turn the palm down.

Supination

Rotating the forearm to turn the palm up.

Inversion

Turning the sole of the foot inward.

Eversion

Turning the sole of the foot outward.