capitis. 3. Demonstrate the action of these muscles in your own body.
4. Locate the origins and insertions of these muscles in the human skull and
5. Complete Parts A and B.
Figure 20.1Label the muscles of expression and mastication.
Figure 20.2 Label these muscles of mastication.
Figure 20.3 Label these deep muscles of the posterior neck (trapezius removed).
Part A Complete the following statements:
1. When the _______________ contracts, the corner of the mouth is drawn upward.
2. The _______________ acts to compress the wall of the cheeks when air is blown out of the mouth.
3. The _______________ causes the lips to close and pucker.
4. The _______________ and platysma help to lower the mandible.
5. The temporalis acts to _______________.
6. The _______________ pterygoid can close the jaw and pull it sideways.
7. The _______________ pterygoid can protrude the jaw, pull the jaw sideways, and open the mouth.
8. The _______________ can close the eye, as in blinking.
9. The _______________ can pull the head toward the chest.
10. The _______________ can pull the head to one side, rotate it, or bring it into an upright position (extend head).
11. The muscle used for pouting and to express horror is the _______________.
12. The muscle used to smile and laugh is the _______________.
Part B Name the muscle indicated by the following combinations of origin and insertion.