Masseter muscle is partly concealed, anteriorly, by the superficial portion. Posteriorly, it is covered by the parotid gland. Along with the other three muscles of mastication (temporalis, medial pterygoid, and lateral pterygoid), the masseter is innervated by the anterior division of the mandibular division (V3) of the trigeminal nerve. The innervation pathway is: gyrus precentralis > genu capsula interna > nucleus motorius nervi trigemini > nervus trigeminus > nervus mandibularis > musculus masseter. The action of the muscle during bilateral contraction of the entire muscle is to elevate the mandible, raising the lower jaw. Elevation of the mandible occurs during the closing
Arches of the foot by bipedally walking apes, which must directly or indirectly reflect the pressure they exert to support and propel themselves do suggest that they exert lower foot pressure under the medial part of their midfoot. However, human feet, and the human medial longitudinal arch, differ in that the anterior part of the foot is medially twisted on the posterior part of the foot, so that all the toes may contact the ground at the same time, and the twisting is so marked that the most medial toe, the big toe or hallux, (in some individuals the second toe) tends to exert