Anatomy of Muscles: Mastication, Facial Expression, Neck, and Forearm

Comprehensive vocabulary flashcards covering the origin, insertion, innervation, and actions of muscles of mastication, facial expression, the posterior forearm, and the neck.

Temporalis Origin

Temporal fossa.

Temporalis Insertion

Coronoid process and anterior border of ramus of mandible.

Temporalis Innervation

Mandibular branch of the trigeminal nerve ($V_3$).

Temporalis Action

Elevation and retraction of the mandible.

Masseter Origin

Inferior margin of zygomatic arch.

Masseter Insertion

Lateral surface of ramus and coronoid process of mandible.

Masseter Innervation

Mandibular branch of the trigeminal nerve ($V_3$).

Masseter Action

Elevation and some protraction of mandible.

Lateral pterygoid Origin

Infratemporal surface of greater wing of sphenoid bone and lateral surface of lateral pterygoid plate.

Lateral pterygoid Insertion

Pterygoid fossa, articular disc and capsule of temporomandibular joint.

Lateral pterygoid Innervation

Mandibular branch of the trigeminal nerve ($V_3$).

Lateral pterygoid Action

Protraction, depression, and lateral movement of mandible to opposite side.

Medial pterygoid Origin

Medial surface of lateral pterygoid plate and tuberosity of maxilla.

Medial pterygoid Insertion

Medial surface of mandible near angle.

Medial pterygoid Innervation

Mandibular branch of the trigeminal nerve ($V_3$).

Medial pterygoid Action

Protraction, elevation, and lateral movement of mandible to opposite side.

Frontalis Action

Raises eyebrows and wrinkles forehead (surprise).

Frontalis Innervation

Facial nerve ($CN, VII$).

Orbicularis oris Action

Puckers lips.

Orbicularis oris Innervation

Facial nerve ($CN, VII$).

Buccinator Action

Compresses cheeks (blowing).

Buccinator Innervation

Facial nerve ($CN, VII$).

Orbicularis oculi Action

Closes eyes tightly.

Orbicularis oculi Innervation

Facial nerve ($CN, VII$).

Brachioradialis Origin

Lateral supracondylar ridge of humerus.

Brachioradialis Insertion

Lateral side of distal radius.

Brachioradialis Innervation

Radial nerve.

Brachioradialis Action

Flexion of forearm.

Extensor carpi radialis longus Origin

Lateral supracondylar ridge of humerus.

Extensor carpi radialis longus Insertion

Base of second metacarpal.

Extensor carpi radialis longus Innervation

Radial nerve.

Extensor carpi radialis longus Action

Extension and radial deviation of wrist.

Extensor carpi radialis brevis Origin

Common extensor tendon.

Extensor carpi radialis brevis Insertion

Base of third metacarpal.

Extensor carpi radialis brevis Innervation

Radial nerve.

Extensor carpi radialis brevis Action

Extension of wrist.

Extensor digitorum Origin

Common extensor tendon.

Extensor digitorum Insertion

Extensor expansions of four fingers.

Extensor digitorum Innervation

Radial nerve.

Extensor digitorum Action

Extension of DIP, PIP, MP, and wrist joints.

Extensor digiti minimi Origin

Common extensor tendon.

Extensor digiti minimi Insertion

Extensor expansions of little finger.

Extensor digiti minimi Innervation

Radial nerve.

Extensor digiti minimi Action

Extension of DIP, PIP, and MP joints of little finger.

Extensor carpi ulnaris Origin

Common extensor tendon and posterior border of ulna.

Extensor carpi ulnaris Insertion

Base of fifth metacarpal.

Extensor carpi ulnaris Innervation

Radial nerve.

Extensor carpi ulnaris Action

Extension and ulnar deviation of wrist.

Supinator Origin

Lateral epicondyle of humerus and posterior surface of ulna.

Supinator Insertion

Lateral side of proximal radius.

Supinator Innervation

Radial nerve.

Supinator Action

Supination of forearm.

Abductor pollicis longus Origin

Middle of ulna, radius, and interosseous membrane.

Abductor pollicis longus Insertion

Base of 1st metacarpal.

Abductor pollicis longus Innervation

Radial nerve.

Abductor pollicis longus Action

Abduction and extension of thumb at CMC joint.

Extensor pollicis brevis Origin

Middle of radius and interosseous membrane.

Extensor pollicis brevis Insertion

Base of proximal phalanx of thumb.

Extensor pollicis brevis Innervation

Radial nerve.

Extensor pollicis brevis Action

Extension of MP and CMC joints of thumb.

Extensor pollicis longus Origin

Middle of ulna and interosseous membrane.

Extensor pollicis longus Insertion

Base of distal phalanx of thumb.

Extensor pollicis longus Innervation

Radial nerve.

Extensor pollicis longus Action

Extension of IP and MP joints of thumb.

Extensor indicis Origin

Distal ulna and interosseous membrane.

Extensor indicis Insertion

Extensor expansion of index finger.

Extensor indicis Innervation

Radial nerve.

Extensor indicis Action

Extension of DIP, PIP, and MP joints of index finger.

Platysma Origin

Skin and fascia overlaying pectoralis major and deltoid.

Platysma Insertion

Inferior border of mandible and skin of lower face.

Platysma Innervation

Facial nerve ($CN, VII$).

Platysma Action

Tenses skin of neck.

Sternocleidomastoid Origin

Sternal head (Manubrium) and Clavicular head (Medial clavicle).

Sternocleidomastoid Insertion

Mastoid process and lateral superior nuchal line.

Sternocleidomastoid Innervation

Accessory nerve ($CN, XI$).

Sternocleidomastoid Action

Unilateral: side bending (same side) and rotation (opposite side); Bilateral: flexion of head.

Digastric Origin

Anterior belly (digastric fossa) and Posterior belly (mastoid process).

Digastric Insertion

Intermediate tendon connected to hyoid bone.

Digastric Innervation

Anterior belly (branch of $V_3$) and Posterior belly (Facial nerve ($CN, VII$)).

Digastric Action

Elevates hyoid during swallowing.

Stylohyoid Origin

Styloid process of temporal bone.

Stylohyoid Insertion

Hyoid.

Stylohyoid Innervation

Facial nerve ($CN, VII$).

Stylohyoid Action

Elevates and retracts hyoid during swallowing.

Mylohyoid Origin

Mylohyoid line of mandible.

Mylohyoid Insertion

Hyoid.

Mylohyoid Innervation

Branch of trigeminal nerve ($V_3$).

Mylohyoid Action

Elevates hyoid during swallowing.

Geniohyoid Origin

Inferior mental spine of mandible.

Geniohyoid Insertion

Hyoid.

Geniohyoid Innervation

$C_1$.

Geniohyoid Action

Pulls hyoid antero-superiorly in swallowing.

Sternohyoid Origin

Posterior manubrium and medial clavicle.

Sternohyoid Insertion

Hyoid.

Sternohyoid Innervation

Ansa cervicalis (C_1, 2, \\\\& 3).

Sternohyoid Action

Depresses hyoid after elevation during swallowing.

Sternothyroid Origin

Manubrium and first costal cartilage.

Sternothyroid Insertion

Oblique line of thyroid cartilage.

Sternothyroid Innervation

Ansa cervicalis (C_1, 2, \\\\& 3).

Sternothyroid Action

Depresses thyroid cartilage after elevation during swallowing.