Gross Muscle Anatomy

orbicularis oculi origin

Frontal bone

orbicularis oculi insertion

Eyelid

orbicularis oculi action

Closes the eyelids

zygomaticus major origin

Zygomatic bone

zygomaticus major insertion

Skin and muscle at the corner of the mouth

zygomaticus major action

Elevation of the lateral corners of the mouth

zygomaticus minor origin

Zygomatic bone

zygomaticus minor insertion

Skin and muscle at the corner of the mouth

zygomaticus minor action

Elevation of the lateral corners of the mouth

trapezius origin

Occipital bone

trapezius insertion

Acromion and spinous process of the scapula

trapezius action

Elevation of the scapula

infraspinatus origin

Infraspinous fossa of the scapula

infraspinatus insertion

Greater tubercle of the humerus

infraspinatus action

Lateral rotation of the arm at the shoulder

supraspinatus origin

Supraspinous fossa of scapula

supraspinatus insertion

Greater tubercle of the humerus

supraspinatus action

Abduction of the arm at the shoulder

triceps brachii origin

Posterior humerus

triceps brachii insertion

Olecranon of ulna

triceps brachii action

Extension of the forearm at the elbow

biceps brachii origin

Coracoid process

biceps brachii insertion

Radial tuberosity

biceps brachii action

Flexion of the forearm at the elbow

brachialis origin

Distal portion of the anterior humerus

brachialis insertion

Coronoid process of the ulna

brachialis action

Flexion of the forearm at the elbow

flexor carpi radialis origin

Medial epicondyle of the humerus

flexor carpi radialis insertion

Base of metacarpals 2 and 3

flexor carpi radialis action

Flexion of the hand at the carpal joints

extensor digitorum origin

Lateral epicondyle of the humerus

extensor digitorum insertion

Distal phalanges of fingers 2-5

extensor digitorum action

Extension of the fingers at the metacarpal and phalangeal joints

gracilis origin

Ramus and body of the pubis

gracilis insertion

Medial surface of tibia

gracilis action

Abduction of thigh at the hip

rectus femoris origin

Anterior inferior iliac spine

rectus femoris insertion

Tibial tuberosity

rectus femoris action

Flexion of the thigh at the hip

vastus medialis origin

Linea aspera of the femur

vastus medialis insertion

Tibial tuberosity

vastus medialis action

Extension of the lower leg at the knee

buccinator origin

Maxillary bone

buccinator insertion

Orbicularis oris muscle

buccinator action

Compresses the cheeks

masseter origin

Zygomatic arch

masseter insertion

Angle and ramus of the mandible

masseter action

Elevation of the mandible

platysma origin

Fascia of chest

platysma insertion

Lower margin of the mandible

platysma action

Tenses the skin of the neck

sternocleidomastoid origin

Manubrium of the sternum

sternocleidomastoid insertion

Mastoid process of the temporal bone

sternocleidomastoid action

Rotation of the head

pectoralis major origin

Sternum

pectoralis major insertion

Intertubercular sulcus of the humerus

pectoralis major action

Flexion of arm

deltoid origin

Acromion and spinous process of scapula

deltoid insertion

Deltoid tuberosity of the humerus

deltoid action

Abduction of the arm at the shoulder

rectus abdominis origin

Pubic crest and symphysis

rectus abdominis insertion

Xiphoid process of the sternum

rectus abdominis action

Flexion and rotation of the vertebral column

external oblique origin

Lower eight ribs

external oblique insertion

Linea alba

external oblique action

Flexion and rotation of vertebral column

semitendinosus origin

Ischial tuberosity

semitendinosus insertion

Medial aspect of upper tibial shaft

semitendinosus action

extension of the thigh at the hip

semimembranosus origin

Ischial tuberosity

semimembranosus insertion

Medial condyle of the tibia

semimembranosus action

Extends thigh; flexes leg; medially rotates leg

tibialis anterior origin

Lateral condyle of the tibia

tibialis anterior insertion

Medial cuneiform bone

tibialis anterior action

Dorsiflexion of the foot at the tarsal joints

gastrocnemius origin

Medial and lateral condyles of the femur

gastrocnemius insertion

Calcaneus

gastrocnemius action

Plantar flexion of foot at the tarsal joints