Position and action of muscles of the head and neck

2. Triangularis
Position
-Corner of the lower lip,
extends over the chin
Action
-Pulls the corners of the
chin down
Expression

3. Temporalis
Position
- Runs down the side of
the face towards the
upper jaw
Action
- Aids raising and
lowering the jaw when
chewing

4. Frontalis
Position
- Upper part of the
cranium-forehead
Action
- Moves the scalp
forward and raises
eyebrows - surprise
Expression

5. Zygomaticus
Position
- Runs down the cheek
towards the corner of the
mouth
Action
Pulls the corner of the
mouth upwards and
sideways as in smiling Expression

6. Corrugator
Position
Medial end of the
eyebrow
Action
Draws the eyebrows
down and together as in
frowning
Expression

7. Orbicularis occuli
Position
Sphincter muscle
surrounding the eye
orbit.
Action
Open and close the eye
as in winking and
blinking
Expression

8. Orbicularis Oris
Position
A sphincter muscle
surrounding the mouth
Action
Closes and opens the
mouth
Expression

9. Buccinator
Position
Run through the angle of
the cheek to the corners
of the mouth
Action
Compresses food in the
cheeks when eating and
allows the blowing
action Expression

10. Risorius
Position
Corners of the mouth
above the Buccinator
muscle
Action
Pulls the corner of the
mouth upwards and
sideways as in grinning Expression

11. Masseter
Position
Run down the face to the
angle of the jaw
Action
Lifts, lowers and closes
the jaw aiding
mastication by exerting
pressure on teeth
Expression

12. Depressor labii inferiore
Position
Underside of the lower
lip, either side of the
mentalis muscle
Action
To depress the lower lip
Expression

13. Platysma
Position
Front and side of the
neck, down to the
clavicle
Action
Depresses lower jaw and
lip wrinkling skin tissue
on neck

14. Mentalis
Position
Attached to the lower
jaw and the lower lip at
the point of the chin
Action
Lifts and wrinkles the
chin turns lower lip
outwards as in pouting
Expression

15. Nasalis
Position
Over the front of the
nose
Action
Compresses and dilates
the nostril openings
causing wrinkling
Expression

16. Procerus
Position
Top of the nose between
the eyebrows
Action
Depresses the eyebrows
and forms wrinkles over
the bridge of the nose

17. Quadratus labii Superiore
Position
Runs upwards from
upper lip in four separate
groups
Action
Lifts the upper lip and
helps open the mouth

18. Sternocleido Mastoid
Position
Either side of the neck to
sternum and clavicle
Action
Individually rotates the
head to one side, pulls
head down to shoulder
and together pulls the
chin onto the chest

19. Pectoralis major
Position
Front of the chest, under the breast.
Action
Pulls the arm forward and assists with
rotation

20. Deltoid
Position
Caps the shoulder
Action
Raises the arm to the side,
Pulls it back and forward again

21. Occipitalis
Position
At the back of the skull
Action
Helps with movement of the head

22. Trapezius
Position
Upper back and sides of neck
Action
Rotation of shoulders, draws back
scapula ie, braces shoulders, pull head back