Muscles and their actions Pt.1

frontalis

raises eyebrows, wrinkles forehead

orbicularis oculi

closes eyes

orbicularis oris

closes and purses lips

buccinator

compresses cheeks

masseter

elevates mandible (closes jaw)

temporalis

elevates mandible

sternocleidomastoid

flexion of head when both sides are contracted

external intercostals

elevates rib cage during inhalation

internal intercostals

depress rib cage during forced exhalation

diaphragm

prime mover of inspiration

external oblique

compress abdominal wall, trunk rotation, and lateral flexion

internal oblique

compresses abdominal wall, trunk rotation, and lateral flexion

rectus abdominis

flexes vertebral column

pectoralis minor

draws scapula forward and downward

serratus anterior

draws scapula forward

trapezius

elevates and retracts scapula

pectoralis major

flexes and adducts arm

latissimus dorsi

extends and adducts arm

deltoid

abducts arm

biceps brachii

flexes forearm/elbow

brachialis

flexes forearm/elbow

Triceps brachii

extends forearm/elbow

hand flexor group

flexes hands/wrist

hand extensor group

extends hand/wrist

iliopsoas

flexion of thigh/hip

Sartorius

flexes and laterally rotates thigh/hip

Rectus femoris

extends knees and flexes thigh/hip