The digestive system is made up of several structures designed to allow the body to take in food and water for nourishment. The mouth is the first section of the alimentary canal, the tube lined with a mucous membrane of the digestive system, in which food is taken in and digested and unnecessary elements are eliminated. The opening of the mouth is formed by the joining of the upper and lower jaws, the maxilla and mandible respectively. The levator veli palatini is a muscle located within the mouth.
Attaching inside the mouth, the dense, somewhat curved muscle known as the levator veli palatini stems from two different attachment sites. Laterally, this muscle hooks onto the underside of the temporal bones, the two bones located on the sides of the head in the temple region. Medially, the levator veli palatini attaches to the Eustachian tube — also referred to as the auditory tube — that runs from the middle ear to the nasophaynx, the upper most portion of the throat. The main job of this muscle is to elevate the soft palate. When the body is ready to swallow foodstuff, the raising of the soft palate, the soft tissue in the uppermost portion of the back of the mouth, prevents food particles and fluids from spilling into the nasophaynx, the area above the soft palate.
Nerves called the pharangeal plexus run through the elevator muscle known as the levator veli palatini to allow signals from the brain to direct appropriate contraction and relaxation of the muscle. The main branch of the plexus is the vagus nerve. Also called cranial nerve X or the pneumogastric nerve, the vagus nerve stems directly from the brain, particularly from the brain stem, the portion of the brain in direct correlation with the spinal cord. In addition to directing the levator veli palatini muscle to contract, the vagus nerve supplies sensation to the area of the roof of the mouth.
Since the levator veli palatini muscle also attaches to the auditory tube, it plays an important part in equalizing air pressure between the tympanic canal, a small cavity surrounding the bones of the middle ear, and the pressure outside of the body. This balancing of air pressures helps stabilize the internal body and prevents damage of the tympanic membranes inside the canal which can diminish hearing abilities. This equalization of pressures is most commonly performed by yawning, a movement where the levator veli palatini muscle must contract to allow the mouth to open.