Submissive grinning, sometimes called smiling, is when a dog pulls up their front lips to expose their teeth (check out a video here and a photo here) and it often occurs during an initial greeting (dog to human, dog to dog).
There are three main functions that the muscle fascia performs: 1  The fascia holds the muscle together and keeps it in the correct place. 2  The fascia separates the muscles so they can work independently of each other. 3  The fascia provides a lubricated surface so that the muscles can move smoothly against each other.here are three main types of fascia: 1  Superficial Fascia, which is mostly associated with the skin; 2  Deep Fascia, which is mostly associated with the muscles, bones, nerves and blood vessels; and. 3  Visceral (or Subserous) Fascia, which is mostly associated with the internal organs.
Each fascicle is composed of fasciculi which are bundles of muscle fibers. The muscle fibers are in turn composed of tens of thousands of thread-like myofybrils, which can contract, relax, and elongate (lengthen). The myofybrils are (in turn) composed of up to millions of bands laid end-to-end called sarcomeres.