KIN 223 Chapter 11

Superior/Proximal Attachment (Origin)

The fixed, non-moving end of a muscle. (Example: Biceps attachment at the shoulder).

Inferior/Distal Attachment (Insertion)

The moving end of a muscle that pulls toward the origin. (Example: Biceps attachment at the radius).

Circular Muscle (Sphincter)

Concentric fibers that close an opening. (Example: Orbicularis oris / mouth).

Parallel Muscle

Fibers running in one direction; high endurance. (Example: Sartorius / inner thigh).

Convergent Muscle

Broad origin tapering to one tendon. (Example: Pectoralis major / chest).

Pennate Muscle

Feather-shaped fibers; high power. (Example: Deltoid / shoulder).

Agonist (Prime Mover)

The muscle primarily responsible for a movement. (Example: Biceps brachii in elbow flexion).

Antagonist

The muscle that opposes or reverses the movement. (Example: Triceps brachii during elbow flexion).

Synergist

A muscle that helps the agonist and stabilizes joints. (Example: Brachialis helping the biceps).

Extrinsic Eye Muscles

Six muscles that move the eyeball. (Example: Lateral rectus moves the eye outward).

Muscles of Mastication

Four muscles used for chewing. (Example: Masseter elevates the mandible).

Extrinsic Tongue Muscles

Muscles outside the tongue that move it. (Example: Genioglossus sticks the tongue out).

Suprahyoid Muscles

Muscles above the hyoid that lift it to swallow. (Example: Digastric).

Infrahyoid Muscles

Muscles below the hyoid that pull it down after swallowing. (Example: Sternohyoid).

Anterolateral Neck Muscles

Muscles that flex or rotate the head. (Example: Sternocleidomastoid).

Erector Spinae

Deep back muscles that extend the spine. (Example: Iliocostalis).

Diaphragm

The dome-shaped muscle that drives breathing. (Example: Flattens to inhale).

External Intercostals

Rib muscles that assist inhalation. (Example: Elevate the ribs).

Internal Intercostals

Rib muscles that assist forced exhalation. (Example: Depress the ribs).

Abdominal Wall Muscles

Four layers that compress the core. (Example: Transversus abdominis / deepest layer).

Pelvic Floor Muscles

Muscles that support pelvic organs. (Example: Levator ani).

Rotator Cuff Muscles (SITS)

Four muscles stabilizing the shoulder. (Example: Supraspinatus).

Anterior Arm Compartment

Muscles that flex the elbow. (Example: Biceps brachii).

Posterior Arm Compartment

Muscles that extend the elbow. (Example: Triceps brachii).

Anterior Forearm Compartment

Muscles that flex the wrist and fingers. (Example: Flexor carpi radialis).

Posterior Forearm Compartment

Muscles that extend the wrist and fingers. (Example: Extensor digitorum).

Intrinsic Hand Muscles

Small muscles within the hand for fine movement. (Example: Thenar group / thumb base).

Gluteal Group

Muscles that move the hip. (Example: Gluteus maximus extends the hip).

Quadriceps Femoris

Four anterior thigh muscles that extend the knee. (Example: Rectus femoris).

Hamstrings

Three posterior thigh muscles that flex the knee. (Example: Biceps femoris).

Adductor Group

Medial thigh muscles that pull legs together. (Example: Adductor longus).

Anterior Leg Compartment

Muscles that lift the foot (dorsiflexion). (Example: Tibialis anterior).

Lateral Leg Compartment

Muscles that turn the foot outward (eversion). (Example: Fibularis longus).

Posterior Leg Compartment

Muscles that point the toes (plantar flexion). (Example: Gastrocnemius).