Human Anatomy: Appendicular and Axial Muscle Structures and Functions

Levator scapulae

A muscle that elevates the scapula.

Pectoralis minor

A muscle that helps in the movement of the scapula and elevates the ribs.

Rhomboids (Rhomboideus)

Muscles that retract the scapula and stabilize it.

Serratus anterior

A muscle that protracts the scapula and assists in upward rotation.

Trapezius

A muscle that elevates, retracts, and rotates the scapula.

Deltoid

A muscle responsible for shoulder abduction, flexion, and extension.

Latissimus dorsi

A muscle that extends, adducts, and medially rotates the arm.

Pectoralis major

A muscle that flexes, adducts, and medially rotates the arm.

Teres major

A muscle that assists in the adduction and medial rotation of the arm.

Rotator cuff

A group of muscles that stabilize the shoulder joint.

Infraspinatus

A rotator cuff muscle that laterally rotates the arm.

Subscapularis

A rotator cuff muscle that medially rotates the arm.

Supraspinatus

A rotator cuff muscle that assists in arm abduction.

Teres minor

A rotator cuff muscle that laterally rotates the arm.

Biceps brachii

A muscle that flexes the elbow and supinates the forearm.

Brachialis

A muscle that flexes the elbow.

Triceps brachii

A muscle that extends the elbow.

Brachioradialis

A muscle that flexes the forearm at the elbow.

Pronator teres

A muscle that pronates the forearm.

Supinator

A muscle that supinates the forearm.

Flexor carpi radialis

A muscle that flexes and abducts the wrist.

Flexor carpi ulnaris

A muscle that flexes and adducts the wrist.

Flexor digitorum

A muscle that flexes the fingers.

Extensor carpi radialis

A muscle that extends and abducts the wrist.

Extensor carpi ulnaris

A muscle that extends and adducts the wrist.

Extensor digitorum

A muscle that extends the fingers and wrist.

Iliopsoas

A muscle that flexes the hip.

Gluteus maximus

A muscle that extends and laterally rotates the hip.

Gluteus medius

A muscle that abducts and medially rotates the hip.

Gluteus minimus

A muscle that abducts and medially rotates the hip.

Quadriceps femoris

A group of muscles that extend the knee.

Sartorius

A muscle that flexes the hip and knee.

Hamstring muscles

A group of muscles that flex the knee and extend the hip.

Gastrocnemius

A muscle that plantar flexes the foot and flexes the knee.

Soleus

A muscle that plantar flexes the foot.

Calcaneal tendon (Achilles tendon)

A tendon that connects the calf muscles to the heel bone.

Contractility

The ability of muscle tissue to shorten and generate force.

Excitability

The capacity of muscle tissue to respond to stimuli.

Extensibility

The ability of muscle tissue to be stretched without damage.

Elasticity

The ability of muscle tissue to return to its original shape after being stretched or contracted.

Tendon

A fibrous connective tissue that attaches muscle to bone.

Aponeurosis

A flat sheet of connective tissue that connects muscles to the parts they move.

Belly

The central, fleshy part of a muscle between its tendons.

Agonist (prime mover)

A muscle that is primarily responsible for a specific movement.

Antagonist

A muscle that opposes the action of another muscle.

Synergists

Muscles that assist the agonist in performing a movement.

Fixators

Muscles that stabilize the origin of the agonist muscle so that it can act more efficiently.

Pennate

A muscle shape characterized by short fibers that attach to a central tendon.

Unipennate

A pennate muscle with fibers that are arranged on one side of the tendon.

Bipennate

A pennate muscle with fibers that are arranged on both sides of the tendon.

Multipennate

A pennate muscle with multiple tendons and fibers arranged around them.

Parallel

A muscle shape where fibers run parallel to the length of the muscle.

Convergent

A muscle shape where fibers converge toward a single tendon.

Circular - sphincter

A muscle shape that encircles an opening and constricts it when contracted.

Buccinator

A muscle of facial expression that compresses the cheeks.

Temporalis

A muscle of mastication that elevates and retracts the mandible.

Masseter

A muscle of mastication that elevates the mandible.

Sternocleidomastoid

A muscle that rotates and flexes the head and neck.

Diaphragm

The primary muscle of respiration that separates the thoracic and abdominal cavities.

Rectus abdominis

A muscle of the abdominal wall that flexes the vertebral column.

External oblique

A muscle of the abdominal wall that aids in trunk rotation and lateral flexion.

Internal oblique

A muscle of the abdominal wall that assists in trunk rotation and lateral flexion.

Transversus abdominis

A muscle of the abdominal wall that compresses the abdominal contents.