BIOL 223L - Muscles of HNT

Frontalis

Elevates / Raises eyebrows; Wrinkles forehead

Cranial Nerve VII: Facial Nerve

Occipitalis

Tenses and retracts scalp (back of the head)

Orbicularis Oculi

Closes eye/Squints eye

Risorius

Abduct corners of mouth

Zygomaticus Major

Retracts and elevates the corner of the mouth

Cranial Nerve VII: Facial Nerve

Zygomaticus Minor

Retracts and elevates the corner of the mouth

Buccinator

Compresses cheek (Pulls cheeks in)

Cranial Nerve VII: Facial Nerve

Orbicularis Oris

Compresses and purses lip

Cranial Nerve VII: Facial Nerve

Mentalis

Elevates and protrudes lip

Platysma

Tenses skin of neck; Depresses lower lip by depressing the mandible

Cranial Nerve VII: Facial Nerve

Masseter

Elevates mandible; Closes Jaw

Cranial Nerve V: Trigeminal Nerve

Temporalis

Elevates and retracts mandible

Cranial Nerve V: Trigeminal Nerve

Medial Pterygoid

Elevate the Mandible

Cranial Nerve V: Trigeminal Nerve

Lateral Pterygoid

Depresses the mandible (unclocks the TMJ)

Cranial Nerve V: Trigeminal Nerve

Rectus Abdominis

Compresses abdominal wall, Flexes vertebral column

External Oblique

Compresses abdomen; Depresses ribs; Flexes or bends spine

Internal Oblique

Compresses abdomen; Depresses ribs; Flexes or bends spine

Transversus Abdominis

Compresses abdomen; Depresses ribs; Flexes or bends spine

Sternocleidomastoid

Flexes neck if both (cervical flexion); Contralateral rotation (is only one moves) Depresses ribs

Cranial Nerve XI: Accesory Nerve

Diaphragm

Expands thoracic cavity; Compresses abdominopelvic cavity

Internal Intercostals

Elevates ribs

External Intercostals

Depresses and protracts shoulder

Pectoralis Minor

Depresses scapula; Elevates ribs

Serratus Anterior

Protracts shoulder; Rotates scapula so glenoid cavity moves superiorly; Adducts scapula and performs downward rotation

Trapezius

Cervical Extension Extends clavicle; Extends and laterally flexes neck

Accesory Nerve XI

Levator Scapulae

Elevates, retracts and rotates scapula

Rhomboideus Major

Adducts scapula and performs downward rotation

Rhomboideus Minor

Adducts scapula and performs downward rotation

Iliocostalis

Extends vertebral column

Longissimus

Extends vertebral column

Spinalis Thoracis

Extends vertebral column