Origin, Insertion and Action of Major Muscles
Muscles Ori
g
in Insertion
A
ction
masseter zy
g
omatic bone
(
z
yg
omatic arch
)
posterior 1/3 mandible elevates mandible
temporalis temporal bone
(temporal fossa) coronoid process of
mandible elevates mandible
digastric inferior mandible,
tem
p
oral hyoid bone depresses mandible
Neck
Muscles
sternocleidomastoid manubrium and medial
clavicle mastoid process of
temporal bone single: rotate head to
opposite side; both: flex head
Abdominal
Muscles
rectus abdominus pubic symphysis xiphoid process, costal
cartilages of ribs 5-7 flexes vertebral column,
compresses abdomen
trapezius occipital bone, dorsal
spinous processes
(thoracic vertebrae)
clavicle, scapula
(acromion process,
spine)
extends head; elevates
scapula
latissimus dorsi dorsal spine (T7 to
sacrum
),
iliac cres
t
humerus (proximal
1/3
)
extends arm; adducts and
mediall
y
rotates arm
rhomboids (ma
j
or &
minor
)
dorsal spinous
p
rocesses of C7-T5 medial border of
sca
p
ula adducts scapula
deltoid clavicle, acromion
process, spine of
sca
p
ula
deltoid tuberosity of
humerus abducts arm
triceps brachii scapula and humerus olecranon process of
ulna extends forearm
pectoralis major clavicle, sternum,
costal cartilages of ribs
1-7
greater tubercle of
humerus flexes arm; adducts, and
medially rotates arm
biceps brachii coracoid process and
supraglenoid tubercle
of sca
p
ula radial tuberosity flexes forearm
iliopsoas transverse processes of
T12-L5; iliac fossa lesser trochanter of
femur major flexor of thigh
sartorius anterior superior iliac
s
p
ine proximal tibia flexes and laterally rotates
thi
g
h
origin - attachment point of the muscle that does not move during muscular contractio
n
insertion - attachment that moves during contraction
action - effect the muscle has on a part of the bod
y
Muscles of
Mastication
Posterior Muscles Acting on the
Shoulder, Arm or Forearm
Anterior Muscles
Acting on the
Shoulder, Arm or
Forearm
Muscles of the
Medial Thigh
WCJC-BIOL 2401 Page 1 of 2 Rev 010609
