CBIO 2200L - Axial Musculture (Actions & Innervations)

frontalis

action: raise eyebrows, draw scalp anteriorly

innervation: facial nerve (VII)

temporalis

action: elevate (closes) mandible

innervation: trigeminal nerve (V)

masseter

action: elevate (closes) mandible

innervation: trigeminal nerve (V)

orbicularis oculi

action: close eyelid

innervation: facial nerve (VII)

orbicularis oris

action: close lips

innervation: facial nerve (VII)

risorius

action: abduct corner of mouth (draws corner of mouth laterally)

innervation: facial nerve (VII)

mentalis

action: protrude lower lip

innervation: facial nerve (VII)

buccinator

action: compress cheek

innervation: facial nerve (VII)

zygomaticus (major and minor)

action: elevate corner of mouth (in smiling and laughing)

innervation: facial nerve (VII)

depressor labii inferioris

action: depress inferior lip

innervation: facial nerve (VII)

levator labii superioris

action: elevator superior lip, flares nostril

innervation: facial nerve (VII)

levator scapulae

action: elevate scapula, abduct and rotate neck

innervation: spinal nerves C3-5 and posterior scapular nerve

scalenes (anterior, middle, posterior)

action: flex and rotate neck, elevate ribs 1 and 2

innervation: spinal nerves C3-8

sternocleidomastoid

action: abduct, rotate, and flex head

innervation: spinal nerves C2-4, accessory nerve (XI)

omohyoid

action: depress hyoid bone

innervation: spinal nerves C1-3

platysma

action: depress inferior lip, open jaw

innervation: facial nerve (VII)

digastric

action: open mouth; depress mandible

innervation: trigeminal (V) and facial (VII) nerves

mylohyoid

action: elevate hyoid bone and tongue

innervation: trigeminal nerve (V)

erector spinae (iliocostalis, longissimus, spinalis)

action: extend and rotate vertebral column and head

innervation: dorsal rami of spinal nerves

pectoralis major

action: flex, adduct, and medially rotate humerus

innervation: medial and lateral pectoral nerves

pectoralis minor

action: depress glenoid cavity

innervation: medial and lateral pectoral nerves

trapezius

action: extend and abduct head; rotate and adduct scapula; fix scapula

innervation: accessory nerve (XI)

latissimus dorsi

action: extend, adduct, and medially rotate humerus; draw shoulder inferiorly

innervation: thoracodorsal nerve

rhomboid (major and minor)

action: adduct scapula

innervation: dorsal scapular nerve

external intercostals

action: elevate ribs (increases volume in thorax)

innervation: intercostal nerves

internal intercostals

action: elevate and depress ribs

innervation: intercostal nerves

diaphragm

action: inspiration

innervation: phrenic nerve

external abdominal oblique

action: compress abdominal wall, laterally rotate waist

innervation: intercostal nerves T7-12

internal abdominal oblique

action: compress abdominal wall, laterally rotate waist

innervation: intercostal nerves T7-12, spinal nerve L1

transverse abdominal

action: compress abdominal wall, laterally rotate waist

innervation: intercostal nerves T7-12, spinal nerve L1

rectus abdominis

action: flex vertebral column, compress abdominal wall

innervation: intercostal nerves T6-12

serratus anterior

action: abduct scapula (moves scapula away from spinal column)

innervation: long thoracic nerve

quadratus lumborum

action: extend and abduct vertebral column

innervation: L1-4, T12