Muscles, Bones, Joints & Movement Study Guide

Axial Skeleton

The foundational central framework of the skeleton, consisting of the skull, vertebral column (spine), ribs, and sternum.

Appendicular Skeleton

The bones comprising the upper and lower extremities along with their supporting shoulder (clavicle, scapula) and pelvic girdles.

Ligament

A tough, fibrous band of connective tissue connecting bone to bone to stabilize joints and limit abnormal movement.

Tendon

A high-tensile band of fibrous connective tissue connecting muscle to bone to transmit force and produce movement.

Cartilage

Smooth, resilient connective tissue that lines joint surfaces to reduce friction between bones and absorb shock.

Deltoid

Shoulder muscle that functions as the primary abductor of the arm and assists in arm flexion and rotation.

Pectoralis Major

Large chest muscle responsible for adduction, medial rotation, and horizontal flexion of the humerus across the chest.

Biceps Brachii

Anterior upper arm muscle that flexes the elbow joint and acts as a powerful supinator of the forearm.

Triceps Brachii

Posterior upper arm muscle that functions as the primary extensor of the elbow joint.

Quadriceps

Anterior thigh muscle group that serves as a powerful extensor of the knee joint and assists in hip flexion.

Hamstrings

Posterior thigh muscle group responsible for flexing the knee joint and extending the hip joint.

Gastrocnemius

Calf muscle that plantarflexes the foot at the ankle joint and assists in knee flexion.

Tibialis Anterior

Muscle located on the front of the shin that serves as the primary dorsiflexor of the foot.

Ball-and-Socket Joint

Multi-axial joint allowing movement in all directions including rotation and circumduction (e.g., shoulder and hip).

Hinge Joint

Uniaxial joint permitting back-and-forth movement in a single plane, specifically flexion and extension (e.g., elbow and knee).

Pivot Joint

Uniaxial joint allowing rotation around a longitudinal axis (e.g., the neck articulation between atlas and axis vertebrae).

Saddle Joint

Biaxial joint permitting flexion, extension, abduction, and adduction (e.g., carpometacarpal joint of the thumb).

Gliding Joint

Non-axial joint allowing small sliding or slipping motions between flat bone surfaces (e.g., wrist carpals and ankle tarsals).

Flexion

Anatomical movement that decreases the angle between articulating bones (e.g., bending the elbow).

Extension

Anatomical movement that increases the angle between articulating bones (e.g., straightening the elbow).

Abduction

Lateral movement that carries a limb away from the midline of the body.

Adduction

Medial movement that brings a limb toward the midline of the body.

Pronation

Forearm rotation that turns the palm downward or posteriorly.

Supination

Forearm rotation that turns the palm upward or anteriorly.

Dorsiflexion

Ankle movement that lifts the foot and toes upward toward the shin.

Plantarflexion

Ankle movement that points the foot and toes downward away from the shin.

Trapezius

Upper back and neck muscle that stabilizes, elevates, and depresses the scapula while supporting neck movement.

Latissimus Dorsi

Broad muscle of the middle and lower back that adducts, extends, and medially rotates the arm.

Gluteus Maximus

Large muscle of the buttocks that extends and externally rotates the hip joint.

Circumduction

Circular limb motion that combines flexion, extension, abduction, and adduction.

Rotation

Movement in which a bone turns around its own central longitudinal axis.

Immovable Joint

A fixed articulation permitting no movement between adjoining bones, such as cranial sutures.

Partially Moveable Joint

An articulation that permits restricted, slight motion, such as the discs between spinal vertebrae.

Anterior

Directional term denoting a position toward the front surface of the body.

Posterior

Directional term denoting a position toward the back surface of the body.

Superior

Directional term describing a structure located closer to the head or above another structure.

Inferior

Directional term describing a structure located closer to the feet or below another structure.

Medial

Directional term indicating a position closer to the midline dividing the body.

Lateral

Directional term indicating a position farther away from the midline toward the outer edge of the body.

Proximal

Directional term denoting a location on a limb that is closer to the trunk or point of attachment.

Distal

Directional term denoting a location on a limb that is farther from the trunk or point of attachment.

Superficial

Directional term describing a structure positioned closer to the external surface of the body.

Deep

Directional term describing an internal structure situated farther away from the outer surface of the body.