The text describes various muscles related to facial and jaw movement, detailing their functions and locations. It explains how these muscles assist with actions like chewing, opening nostrils, and moving the jaw in various directions. Illustrations referenced provide visual support for understanding these anatomical details.
Muscles and Their Functions.
Their shape is round and begins at the upper jawbone, and they are implanted in the lower part of the gums: they move the jaws with the lips and assist the teeth in pressing food by pushing it back and forth to grind it; they also help in blowing, as trumpet players would know. See illustration A and B.
5. This is the muscle of the lower lip. See illustration B.
6. This muscle also starts from the cheekbone and ends at the tip of the nose. See illustration A.
7. This is the muscle that opens the nostrils. See illustration B.
8. Named Masseter or Chewer; because the function of this muscle is to chew food; it moves the jawbone in various directions: forwards, backwards, upwards, and downwards. This is why nature has aligned the heads crosswise like an X, to facilitate such movements more smoothly. See illustration B, C.
9. The muscle that slightly lifts the Hyoid bone: There are two of these, sprouting from the front of the chin and attaching to the foot of the Hyoid bone. See illustration B and C.
10. The muscles that pull down the Hyoid bone: There are two of these as shown in figure B: They sprout from the top part of the Sternum or Breastbone and attach to the foot of the Hyoid. See illustration A and B.
11. Sternocleidomastoid. This muscle bends the head forward. There are two on either side,
Translation Notes:
- "Masseter" refers to the muscle responsible for chewing. - "Hyoid" references the U-shaped bone in the neck that supports the tongue.