Lab Practical Muscle Actions

Epicranius(frontalis and occipitalis)

raise eyebrows

Orbicularis oculi

squinting and blinking

levator labii superioris

raises and everts upper lip

orbicularis oris

puckers lips

zygomaticus major and minor

raises corners of lips(smiling)

depressor anguli oris

pulls corners of mouth inferior and lateral(frowning)

depressor labii inferioris

pulls inferior and protrudes lower lip(pouting)

mentalis

pulls inferior and protrudes lower lip(pouting)

buccinator

pulls corners of mouth laterally and compresses cheeks(whistling)

risorius

pulls corners of mouth laterally

masseter

closes mouth, elevates jaw

temporalis

closes mouth, elevates jaw

sternocleidomastoid

both sides flexes head or one side rotates towards opposite side

sternohyoid

depresses hyoid and larynx during speech

omohyoid

depresses hyoid

scalenes

both sides flexes head, one side rotates towards opposite side, elevates ribs 1-2

Pectoralis major

flexion, adduction, and medial rotation of humerus

Pectoralis minor

pulls scapula forward and down

serratus anterior

pulls scapula anteriorly and rotates it

external intercostals

lifts rib cage up and out during exhalation

internal intercostals

draws rib cage in and closer together during exhalation

diaphragm

moves inferiorly to increase volume of thorax during inhalation

external oblique

lateral flexion and rotation of trunk

internal oblique

lateral flexion and rotation of trunk

transverse abdominis

compresses abdomen

rectus abdominis

flexes trunk

trapezius

elevates, depresses, and adducts scapula

deltoid

abduction, flexion, and medial rotation of arm

supraspinatus

abducts arm

infraspinatus

lateral rotation of humerus

teres minor

adduction and lateral rotation of humerus

teres major

adduction, medial rotation, and extension of humerus

subscapularis

medial rotation of humerus

levator scapula

elevates scapula

rhomboid major and minor

adducts scapula

splenius

extends head, flexes and rotates toward contracted side

latissimus dorsi

adduction, medial rotation, and extension of humerus

posterior serratus

pulls lower ribs, inferiorly, assists in rotation and extension of lower trunk

erector spinae

lateral flexion, extension, and hyperextension of trunk

biceps brachii

flexes elbow and arm

brachialis

flexes forearm

triceps brachii

extension of forearm

anconeus

extension of forearm

pronator teres

pronates forearm

brachioradialis

flexes forearm

supinator

supines forearm

sartorius

flexes, abducts, and laterally rotates thigh

gracilis

adducts thigh

vastus medialis

extends knee

rectus femoris

extends knee, flexes thigh

vastus lateralis

extends knee

vastus intermedius

extends knee

iliacus

flex the hip and assist in flexion of trunk

psoas

flex the hip and assist in flexion of trunk

pectineus

flexes and adducts thigh

adductor longus

adducts thigh, assists in flexion and medial rotation of hip

adductor brevis

adducts thigh, assists in flexion and medial rotation of hip

adductor magnus

adduction and medial rotation of hip

semimebranosus

extends thigh and flexes knee

semitendinosus

extends thigh, flexes knee

biceps femoris

extends thigh, flexes knee, assists in lateral rotation of thigh

tensor fascia lata

flexes and abducts thigh

gluteus maximus

extends and abduct thigh, assists in lateral rotation of thigh

gluteus medius

abduction and medial rotation of thigh

gluteus minimus

abduction and medial rotation of thigh

gastrocnemius

flexion of knee, plantar flexion of ankle

soleus

plantar flexion of ankle

popliteus

unlocks extended knee, knee flexion

fibularis(peroneus)

plantar flexion

tibialis anterior

dorsiflexes foot at ankle

extensor digitorum

extends toes, dorsiflexion of foot

superficial perineal

supports pelvic organs, stabilizes central tendon of perineum

deep transverse perineal

supports pelvic organs, stabilizes central tendon of perineum

ischiocavernous

maintains erection of penis and clitoris

bulbospongiosus

assists in maintaining erection of penis and clitoris, empties male urethra during ejaculation

pubococcygeus

tenses pelvic floor, supports pelvic organs, elevates anus

iliococcygeus

tenses pelvic floor, supports pelvic organs, elevates anus

coccygeus

supports pelvic organs

external anal sphincter

voluntary control of defacation