PSIO 201 Practical 3 - Muscle Locations

Frontalis

Raises eyebrows

Occipitalis

Draws scalp posteriorly

Orbicularis oris

puckers mouth as in kissing

Orbicularis oculi

closes eye as in blinking

Zygomaticus major

pulls corners of mouth superiorly as in smiling

Zygomaticus minor

elevates upper lip to expose upper teeth

Platysma

depresses the lower lip and mandible, tenses skin of neck

Temporalis

elevates and retracts the mandible

Masseter

elevates, protracts, and retracts the mandible

Sternocleidomastoid

If one contracts, the head is rotated

if both contract, flexion of head is result

Rectus abdominis

compresses the abdomen

flexes the vertebral column

External oblique

rotation of the trunk

flexion of the vertebral column

compression of abdomen

Internal oblique

rotation of the trunk

flexion of vertebral column

compression of abdomen

Transverse abdominis

compression of the abdomen

Erector Spinae (iliocostalis group, longissumus group, spinalis group)

rotates the vertebral column

contracts the vertebral column to maintain erect posture

Diaphragm

increases dimensions of the thorax during inspiration

external intercostals

pulls ribs upwards and together during forced inspiration

internal intercostals

pulls ribs down and together during forced expiration

Pectoralis minor

depresses and protracts scapula

Trapezius

elevates scapula and clavicle

extends the head

adducts scapula

depresses scapula

Levator scapulae

elevates scapula

Rhomboid major

elevates, adducts, and inferiorly rotates scapula

Rhomboid minor

elevates, adducts, and inferiorly rotates scapula

serratus anterior

abducts scapula and rotates it superiorly

contributes to punching motion of the arm

Pectoralis major

flexes, adducts, and medially rotates the arm

Latissimus dorsi

adducts, extends, and medially rotates the arm

Deltoid

medial fibers abduct arm

flex and medially rotate arm

extend and laterally rotate arm

Supraspinatus

abducts the arm

Infraspinatus

laterally rotates and adducts the arm

Teres major

extends, adducts, and medially rotates the arm

Teres minor

extends and laterally rotates arm

subscapularis

medially rotates arm

Biceps brachii

flexes arm

flexes and supinates forearm

Brachialis

flexes forearm

Brachioradialis

flexes forearm

Triceps brachii

extends arm/forearm

Flexor carpi radialis

flexes and abducts hand

Flexor carpi ulnaris

flexes, adducts hand

Palmaris longus

flexes hand

Flexor digitorum superficialis

flexes hand and digits

Flexor digitorum profundus

flexes hand and digits

Extensor carpi radialis brevis

extends and abducts hand

pronator teres

pronates forarm and flexes forarm

Extensor carpi ulnaris

extends and adducts hand

Extensor carpi radialis longus

extends and abducts hand

Extensor digiti minimi

extends hand and digits

Abductor pollicis longus

abducts and extends thumb and abducts hand

Extensor pollicis brevis

extends thumb

abducts hand

Iliacus

flexes the thigh

originates on illium

inserts on femur

Psoas major

flexes the thigh

originates on the lower vertebrae

inserts on the proximal femur

Piriformis

laterally rotates and abducts the thigh

originates on sacrum

inserts on femur

Tensor fascia latae

flexes and abducts thigh

originates on illiac crest

inserts on tibia via the IT band

Gluteus maximus

extends and laterally rotates thigh

originates on illium and sacrum

inserts on femur

Gluteus medius

abducts and medially rotates the thigh

originates on illium

inserts on femur

Gluteus minimus

abducts and medially rotates thigh

originates on illium

inserts on femur

Gracilis

flexes leg and adducts thigh

originates on pubis

inserts on tibia

Adductor magnus

adducts and medially rotates thigh

originates on ischium and pubis

inserts on femur

Adductor longus

adducts, flexes, and medially roates thigh

originates on pubis

inserts on femur

Aductor brevis

adducts, flexes,and medially rotates thigh

originates on pubis

inserts on femur

Rectus femoris

flexes thigh, extends leg

originates on illium

inserts on tibia

Vastus lateralis

extends the leg

originates on femur

inserts on tibia

Vastus medialis

extends the leg

originates on femur

inserts on tibia

Vastus intermedius

extends the leg

originates on femur

inserts on tibia

Satorius

flexes leg and thigh, laterally rotates the thigh

originates on illium

inserts on tibia

Biceps femoris

flexes leg, extends thigh

originates on ischium and femur

inserts on tibia

Semimembranosus

flexes leg, extends thigh

originates on ischium

inserts on tibia

Semitendinosus

flexes leg, extends thigh

originates on ischium

inserts on tibia

Gastrocnemius

plantar flexes the foot, flexes leg

originates on the femur

inserts on the calcaneus

Soleus

plantar flexes foot

originates on the fibula

inserts on the calcaneus

Tibialis anterior

inverts and dorsiflexes the foot

originates on the tibia

inserts onthe 1st metatarsal and cuneiform

Fibularis (peroneus) longus

everts and plantar flexes the foot

originates on tib/fib

inserts on 1st metatarsal and cuneiform

Tibialis posterior

inverts and plantar flexes the foot

originates on the tib/fib

inserts on the inferior surface of many tarsals and metatarsals

Fibularis brevis

everts and plantar flexes the foot

originates on the fibula

inserts on the 5th metatarsal

flexor hallucis longus

plantar flexes foot and flexes great toe

flexor digitorum longus

plantar flexes foot and flexes digits II-IV

Extensor digitorum longus

dorsiflexes the foot, extends digits II-V

originates on the tib/fib

inserts on the middle and distal phalanges of digit II-V