Anatomy Major Human Muscles

Front 1

Frontalis

Back 1

Located on top of the frontal bone
Action: raises eyebrows

Front 2

Occipitalis

Back 2

Located on top of the occipital bone
Action: pulls scalp posteriorly

Front 3

Obicularis oculi

Back 3

Sphincter that surrounds the eye
Action: closing the eyes and squinting

Front 4

Obicularis oris

Back 4

Surrounds the mouth
Action: closes the lips, kissing, whistling

Front 5

Corrugator supercili

Back 5

Located right under the eyebrows
Action: draws eyebrows medially and inferiorly

Front 6

Risorius

Back 6

Runs inferior and lateral to the zygomaticus. Runs from Obicularis oris to the masseter
Action: Draws corner of lip laterally

Front 7

Zygomaticus

Back 7

Extends diagonally from corner of mouth to cheekbone
Action: Smiling

Front 8

Buccinator

Back 8

Runs perpendicular and deep to the masseter
Action: Compresses cheek (whistling)

Front 9

Levator labii superioris

Back 9

Located between the obicularis oris and the bottom of the eye
Action: opens the mouth

Front 10

Depresser labii inferioris

Back 10

Runs from lower lip to the mandible
Action: draws lower lip inferiorly

Front 11

Mentalis

Back 11

Located on the chin
Action: wrinkles the chin

Front 12

Platysma

Back 12

Thin sheetlike muscle that covers the neck
Action: Tenses the skin of the neck

Front 13

Superior rectus

Back 13

Located on the superior side of the eyeball
Action: Moves eyeballs superiorly and medially

Front 14

Inferior rectus

Back 14

Located on the inferior side of the eyeball
Action: Moves eyeballs inferiory and medially

Front 15

Medial rectus

Back 15

Located on the medial side of the eyeball
Action: moves eyeballs medially

Front 16

Lateral rectus

Back 16

Located on the lateral side of the eyeball
Action: Moves eyeballs laterally

Front 17

Superior oblique

Back 17

Runs diagonally across the superior side of the eyeball
Action: Moves eyeballs inferiorly and medially

Front 18

Inferior oblique

Back 18

Runs diagonally across the inferior side of the eyeball
Action: Moves eyeballs superiorly and laterally

Front 19

Masseter

Back 19

Covers the lateral aspect of the mandibular ramus
Origin: Zygomatic arch and the maxilla
Insertion: Angle and ramus of the mandible
Action: Prime mover of jaw closure

Front 20

Temporalis

Back 20

Covers the sides of the skull
Origin: Temporal fossa
Insertion: Coronoid process of the mandible
Action: Closes jaw

Front 21

Medial pterygoid

Back 21

Runs along the medial side of the mandible
Origin: Sphenoid, palatine, and maxilla
Insertion: Medial surface of the mandible
Action: Aids in grinding movements

Front 22

Lateral pterygoid

Back 22

Superior to the Medial pterygoid
Origin: Greater wing of the sphenoid bone
Insertion: Condylar process of the mandible
Action: Aids in grinding movements

Front 23

Sternoclydomastoid

Back 23

Located deep to platysma on anterolateral surface of the neck
Origin: Manubrium of sternum and medial portion of clavicle
Insertion: Mastoid process of temporal bone and superior nuchal line of occipital bone
Action: Flexion of neck forward and rotation of head toward shoulder on opposite side

Front 24

Scalenes (anterior, middle, posterior)

Back 24

Located on anterolateral side of neck; deep to platysma and sternoclydomastoid
Origin: Transverse process of cervical vertebrae
Insertion: Ribs 1-2
Action: Elevate ribs 1-2

Front 25

Rectus abdominis

Back 25

Segmented abdominals that extend from the rib cage to the pubis
Origin: Pubic crest and symphysis
Insertion: Xiphoid process of sternum and costal cartilage of ribs 5-7
Action: Flexes and rotates vertebral column

Front 26

External oblique

Back 26

Most superficial lateral abdominal muscle
Origin: Anterior surface of last eight ribs
Insertion: Linea alba, pubic crest and tubercles, and iliac crest
Action: Flexes and rotates vertebral column; aids in lateral flexion of trunk

Front 27

Internal oblique

Back 27

Located deep of the external oblique
Origin: Lumbar fascia, ilia crest, and inguinal ligament
Insertion: Linea alba, pubic crest, and costal cartilages of last three ribs
Action: Flexes and rotates vertebral column; aids in lateral flexion of trunk

Front 28

Transversus abdominus

Back 28

Lies deep to external and internal obliques
Origin: Inguinal ligament, iliac crest, cartilages of last five-six ribs, and lubar fascia
Insertion: Linea alba and pubic crest
Action: Compresses abdominal contents

Front 29

Pectoralis minor

Back 29

Lies deep to the pectoralis major
Origin: anterior surface of ribs 3-5
Insertion: corocoid process of scapula
Action: draws scapula forward and inferiorly

Front 30

Serratus anterior

Back 30

Lies deep to scapula
Origin: Lateral aspect of ribs 1-8
Insertion: vertebral border of anterior surface of scapula
Action: Prime mover to protract and hold scapula against chest wall; rotates scapula

Front 31

Trapezius

Back 31

Superficial muscles on the posterior side of the thorax
Origin: occipital bone, ligamentum nuchae, spines of C7, and all thoracic vertebrae
Insertion: acromion and spinous process of scapula,l lateral third of clavicle
Action: raises, rotates, and retracts scapula and stabilizes it

Front 32

Levator scapulae

Back 32

Located on the posterior lateral side of neck, deep to trapezius
Origin: Transverse processes of C1-C4
Insertion: Medial border of scapula above the spine
Action: Elevates and adducts the scapula

Front 33

Rhomboids (Major and Minor)

Back 33

Located beneath the trapezius and inferior to the levator scapulae; rhomoid minor is the more superior muscle
Origin: Minor (Spinous process of C7) Major (Spinous processes of T1-T5)
Insertion: Medial border of scapula
Action: Stabilize scapula

Front 34

Erector spinae

Back 34

Long group of muscles that extend from the pelvis to the head
Action: Extend and bend the vertebral column laterally

Front 35

Splenius

Back 35

Superficial muscle that extends from upper thoracic region to skull
Origin: Ligamentum nuchae and spinous processes of C7-T6
Insertion: Mastoid process, occipital bone, and transverse processes of C2-C4
Action: extend and hyperextend the head

Front 36

Latissimus dorsi

Back 36

Superficial muscle covering the lumbar region of the lower back
Origin: Indirect attachment to T7-T12, lumbar vertebrae, last three ribs, and iliac crest
Insertion: humerus
Action: Prime mover of extension; adducts and medially rotates arm

Front 37

Pectoralis major

Back 37

Superficial muscle of the chest
Origin: clavicle, sternum, cartilage of ribs 1-6, and aponeurosis of external oblique muscle
Insertion: humerus
Action: Prime mover of arm flexion; adducts and medially rotates arm

Front 38

Deltoid

Back 38

Superficial shoulder muscle
Origin: Clavicle, acromion and spine of scapula
Insertion: deltoid tuberosity of humerus
Action: Prime mover of arm abduction

Front 39

Supraspinatus

Back 39

Located above the spine of the scapula, deep to trapezius
Origin: Supraspinous fossa of scapula
Insertion: greater tubercle of humerus
Action: initiates abduction of humerus

Front 40

Infraspinatus

Back 40

Located on the scapula below the spine; partially covered by the deltoid and rhomboid
Origin: Infraspinous process of scapula
Insertion: Greater tubercle of humerus
Action: Lateral rotation of humerus

Front 41

Teres minor

Back 41

Inferior to infraspinatus
Origin: Lateral margin of scapula
Insertion: Greater tubercle of humerus
Action: lateral rotation of humerus

Front 42

Teres major

Back 42

Inferior to teres minor
Origin: posterior surface of inferior angle of scapula
Insertion: humerus
Action: extends, medially rotates, and adducts humerus

Front 43

Biceps brachii

Back 43

Most superficial muscle on anterior surface of humerus
Origin: corocoid process (short head) supraglenoid tubercle and lip of glenoid cavity (long head)
Insertion: radial tuberosity of radius
Action: Flexion of elbow and supination of forearm

Front 44

Brachialis

Back 44

Immediately deep to biceps brachii
Origin: distal portion of anterior humerus
Insertion: coronoid process of ulna
Action: flexion of elbow

Front 45

Brachioradialis

Back 45

Superficial muscle of lateral forearm
Origin: Lateral ridge at distal end of humerus
Insertion: base of radial styloid process
Action: synergist in elbow flexion

Front 46

Triceps brachii

Back 46

Superficial muscle of posterior surface of humerus
Origin: Long head (inferior margin of glenoid cavity) lateral head (posterior humerus) medial head (distal radial groove on posterior humerus
Insertion: Olecrannon of ulna
Action: Elbow extension