The text explains the naming, function, and location of visible facial muscles, focusing on the head and neck. It details the role of the temporalis muscle in chewing and its physical characteristics, including its helper known as 'Ore Latitans'. Additionally, it describes muscles responsible for closing the upper eyelid and those related to the cheek and upper lip.
Explanation
Of the naming, function, and placement of the visible muscles according to the illustration ABC.
First, concerning the muscles of the head and neck.
See the illustration at the back of the book near the fold-out page.
1. Temporalis or sleep muscle: so named because it covers both temples of the head or the temple cavities. It helps with chewing, as it closes the mouth because it attaches to the lower jaw. This temporalis muscle can be seen in action while eating various four-footed animals: you can even feel it by hand when clenching down to bite. There is one on each side of the head, and it lifts the lower jaw; it is somewhat broad and fleshy, above semi-rounded, and goes under the zygomatic arch (6) and plants itself in the Coronoide process. It also has a helper known to anatomists as 'Ore Latitans', though this one is not visible. View this muscle in Figures B and C.
2. A muscle that closes the upper eyelid. See Figure B.
3. The muscle that springs from the zygomatic arch (6) and ends in the trumpet or cheek muscle at the upper lip. See Figure A. B.
4. Buccinator, the trumpet or cheek muscle.
Translation Notes:
Sleep muscle: This refers to the temporalis muscle.
Ore Latitans: A term used by anatomists that does not have a direct modern English translation.