Muscles and Actions of the body

Frontalis

superficial to frontal bone

Action of frontalis

raises the eyebrows/wrinkles the brow

Orbuclaris Oris

Muscles near the mouth

Action of Orbicularis Oculi

closes eye as in blinking

Zygomaticus

extends from cheekbones to corners of the mouth

Action of zygomaticus

raises lateral corners of the mouth when smiling

draws angle of mouth upward and laterally

Masseter

Action of masseter

elevataion and protusion the mandible

Temporalis

Action of temporalis

elevatation and retraction of the mandible

Sternocleidomastoid

Action of sternocleidomastoid

flexes and/or laterally rotates the head

Diaphragm

Action of diaphragm

inspiration - contracts to increase intra-abdominal pressure to force air into lungs

External oblique

fibers run down toward midline

Action of of external oblique

flex vertebral column, rotation if one side

Internal oblique

fibers run up toward midline

Action of internal oblique

flex vertebral column, rotation if one side

Rectus abdominis

fibers run up and down

Action of rectus abdominis

flex and rotate lumbar region

Pectoralis major

large chest muscle

Action of pectoralis major

flexes the humerus

extends the humorus

protracts and rotates scapula downward

Serratus anterior

"fingers"

Action of serratus anterior

rotates scapula upward

Trapezius

broad back muscle

Action of trapezius

stabilizes, elevates, retracts, and rotates scapula, extends head

Rhomboids (major and minor)

Action of rhomboids

stabilize scapula

Deltoid

shoulder muscle

Action of deltoid

shoulder abduction, flexion and extension

Latissimus dorsi

broad back muscle

Action of latissimus dorsi

Adducts, extends and internally rotates the arm when the insertion is moved towards the origin.

rotator of the trunk

Teres major

Action of teres major

extends, medially rotates, and adducts the arm

Infraspinatus

rotator cuff muscle

Action of infraspinatus

laterally rotates arm

Teres minor

rotator cuff muscle

Action of teres minor

laterally rotates arm

Triceps brachii

posterior brachial region

Action of triceps brachii

Extends forearm, long head extends, adducts arm, Extends shoulder

Biceps brachii

anterior brachial region

Action of biceps brachii

Flexes elbow

flexes and abducts shoulder

supinates radioulnar joint in the forearm

Brachialis

anterior brachial region

Action of brachialis

flexion at elbow joint

Brachioradials

anterior brachial region

Tensor fasciae latae

Action of tensor fasiae latae

stabilizes trunk

Sartorius

Action of sartorius

flexes, abducts, and laterally rotates thigh

Four heads of quadriceps femoris

-rectus femoris

-vastus lateralis

-vastus medialis

-vastus intermedius

Action of all four quadriceps femoris muscles

extend the leg

Rectus Femoris

Action of rectus femoris

knee extension; hip flexion

Vastus Lateralis

Action of vastus lateralis

Extends and stabilizes knee

Vastus Medialis

Action of vastus medialis

Extends leg

Gracilis

Action of gracilis

adducts thigh, flexes, and medially rotates leg

Three adductors

-brevis

-longus

-magnus

Action of adductors

adducts and medially rotates thigh

Gluteus maximus

Action of gluteus maximus

extends the thigh

Three posterior muscles grouped to make hamstrings

-biceps femoris

-semitendinosus

-semimembranosus

Action of the three hamstring muscles

extend the thigh and flex the leg at the knee

Biceps femoris

Semitendinosus

Semimembranousus

Tibialis anterior

Action of tibilais anterior

dorsiflexion

Extensor digitorum longus

Action of extensor digitorum longus

toe extension

Peroneus (fibularis) longus

Action of peroneus (fibularis) longus

plantar flexion and eversion

Gastrocnemius

large calf muscle

Action of gastrocnemius

plantar flexion

Soleus

deep to gastrocnemius

Action of soleus

plantar flexion

Orbicularis Oculi

maxillary and frontal bones

Action of Orbicularis Oris

closes lips, protrudes lips for kissing

Gluteus Medius

lateral surface of ilium

Action of Gluteus Medius

abducts and rotates thigh medially

Occipitalis

pulls scalp posteriorly

Buccinator

compresses cheek

Platysma

tenses skin of neck

splenius capitis

rotates head, bends head to one side, or extends neck

levator scapulae

elevates scapula

splenus capitis

back of neck

Spraspinatus

Transverse Absominis

compress abdominal contents

Pectineus

adducts, flexes, and medially rotates thigh

Psoas

loin

Iliacus

Flexes thigh on hip

abductor magnus

abducts thigh

flexor carpi radialis

flexes wrist and abducts hand

pronator teres

pronates forearm

palmaris longus

flexes wrist

extensor carpi radialis longus

Extends wrist and abducts hand