Try out PMC Labs and tell us what you think. Learn More. The rhesus macaque Macaca mulatta is the most utilized primate model in the biomedical and psychological sciences. Expressive behavior is of interest to scientists studying these animals, both as a direct variable modeling neuropsychiatric disease, where expressivity is a primary deficit , as an indirect measure of health and welfare, and also in order to understand the evolution of communication.
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Mapping the contribution of single muscles to facial movements in the Rhesus Macaque
Understanding how to prevent muscle deterioration begins with an essential key: having an understanding of the muscles! We all know that we have roughly muscles in throughout the human body, but did you know that 43 are in the face alone, and 36 of those are used for facial expressions! Muscles contract which causes the skin on top of them to wrinkle. Muscles move through contraction; tightening and extension or relaxing. During contraction, the point of insertion moves while the point of origin stays fixed. As we age, muscles gradually lose tone.
The facial nerve is also known as the seventh cranial nerve CN7. This nerve performs two major functions. It conveys some sensory information from the tongue and the interior of the mouth. The nerve extends from the brain stem, at the pons and the medulla. Also, this nerve innervates facial muscles, controlling how to contract and produce facial expressions.