Anatomy 10A Unit Three: Human Muscles and Muscle Actions Term List

Muscles of Facial Expression

  • Frontalis: Elevates eyebrows (surprise).

  • Corrugator supercilii: Adducts eyebrows (frown).

  • Orbicularis oculi: Closes eye.

  • Orbicularis oris: Closes mouth.

  • Buccinator: Compresses cheek (drinking with a straw).

  • Zygomaticus: Elevates corners of the mouth (smiling).

  • Risorius: Opens mouth laterally (open wide).

  • Mentalis: Pushes lower lip out (pouting).

Muscles of Chewing and Neck

  • Masseter: Elevates mandible.

  • Temporalis: Elevates mandible.

  • Platysma (Superficial neck muscle): Tenses anterior neck, depresses mandible, pulls lower lips laterally and inferiorly (grimace).

Muscles of the Hyoid and Neck

  • Mylohyoid (Above the hyoid): Elevates hyoid.

  • Digastric (Above the hyoid): Elevates hyoid, depresses mandible.

  • Stylohyoid (Above the hyoid): Elevates and retracts hyoid.

  • Sternocleidomastoid (Below the hyoid): Flex neck.

  • Sternohyoid (Below the hyoid): Depresses hyoid.

Muscles of the Chest and Abdominal Wall

  • Pectoralis major (Superficial muscle of the chest): Flexes, medially rotates and adducts arm.

  • External abdominal oblique (Abdominal wall): Lateral trunk rotation, abdominal compression.

  • Internal abdominal oblique (Abdominal wall): Lateral trunk rotation, abdominal compression.

  • Transversus abdominis (Abdominal wall): Abdominal compression.

  • Rectus abdominis (Abdominal wall): Flexes vertebral column.

  • External intercostals (Deep muscles of the chest): Elevate ribs (breathing in).

  • Pectoralis minor (Deep muscles of the chest): Protracts and depresses scapula.

  • Serratus anterior (Deep muscles of the chest): Protract scapula.

Superficial Muscles of the Shoulder and Back

  • Latissimus dorsi: Adducts arm.

  • Trapezius: Elevates and adducts scapula, extends neck.

  • Deltoid: Abducts arm.

Deep Muscles of the Posterior Shoulder

  • Levator scapulae (Moves the scapula): Elevates scapula.

  • Rhomboideus major & minor (Moves the scapula): Adducts scapula.

  • Supraspinatus* (Moves the arm): Abducts arm.

  • Infraspinatus* (Moves the arm): Lateral arm rotation.

  • Teres minor* (Moves the arm): Lateral arm rotation.

  • Subscapularis* (Moves the arm): Stabilize humerus, medial arm rotation.

  • Teres major (Moves the arm): Adducts arm, medial arm rotation.

Note: Muscles marked with an asterisk () are muscles of the rotator cuff.

Muscles of the Arm and Forearm Moving the Elbow

  • Biceps brachii (Anterior flexor): Flexes elbow (forearm).

  • Brachialis (Anterior flexor): Flexes elbow (forearm).

  • Brachioradialis (Anterior flexor): Flexes elbow (forearm).

  • Triceps brachii (Posterior extensor): Extends elbow (forearm).

  • Pronator teres (Anterior- rotates radius): Pronates forearm.

Muscles of the Forearm Moving the Wrist and Digits

  • Flexor carpi radialis (Anterior flexor): Flexes and abducts wrist.

  • Palmaris longus (Anterior flexor): Flexes wrist.

  • Flexor carpi ulnaris (Anterior flexor): Flexes and adducts wrist.

  • Extensor carpi radialis longus (Posterior extensor): Extends and abducts wrist.

  • Extensor carpi radialis brevis (Posterior extensor): Extends and abducts wrist.

  • Extensor digitorum (Posterior extensor): Extends digits.

  • Extensor digiti minimii (Posterior extensor): Extends digits.

  • Extensor carpi ulnaris (Posterior extensor): Extends and adducts wrist.

Muscles of the Thigh and Hip

  • Sartorius (Superficial hip and knee flexor): Flexes thigh (hip) and flexes knee (leg).

  • Gluteus maximus (Gluteal group): Extends the thigh (hip).

  • Gluteus medius (Gluteal group): Abducts the thigh (hip).

  • Tensor fascia latae (Gluteal group): Abducts the thigh (hip), extends the leg (knee).

  • Iliacus (Hip flexor group): Flexes the thigh (hip).

  • Psoas major (Hip flexor group): Flexes the thigh (hip).

Quadriceps Femoris Group (Anterior Thigh)

  • Rectus femoris: Extends the knee (leg), flexes the thigh (hip).

  • Vastus lateralis: Extends the knee (leg).

  • Vastus intermedius: Extends the knee (leg).

  • Vastus medialis: Extends the knee (leg).

Hamstring and Adductor Groups

  • Biceps femoris (Hamstring group): Extends the thigh (hip), flexes the knee (leg).

  • Semimembranosus (Hamstring group): Extends the thigh (hip), flexes the knee (leg).

  • Semitendinosus (Hamstring group): Extends the thigh (hip), flexes the knee (leg).

  • Gracilis (Adductor group): Adducts thigh (hip), flexes knee (leg).

  • Pectineus (Adductor group): Adducts thigh (hip).

  • Adductor longus (Adductor group): Adducts thigh (hip).

  • Adductor magnus (Adductor group): Adducts thigh (hip).

Muscles of the Lower Leg

  • Gastrocnemius (Posterior - plantar flexor): Plantar flexes foot.

  • Plantaris (Posterior - plantar flexor): Plantar flexes foot.

  • Soleus (Posterior - plantar flexor): Plantar flexes foot.

  • Tibialis anterior (Tibial muscle): Dorsiflexes and inverts foot.

  • Extensor digitorum longus (Tibial muscle): Extends toes 2-5.

  • Flexor digitorum longus (Tibial muscle): Flexes toes 2-5.

  • Tibialis posterior (Tibial muscle): Inverts foot.

  • Fibularis longus (Peroneus longus) (Fibular muscle): Everts foot.

  • Fibularis brevis (Peroneus brevis) (Fibular muscle): Everts foot.