The velum palatinum consists of two layers of mucous membrane, oral and nasal, with intervening muscular and connective tissue. The muscles of the soft palate in the cat are as follows:
=M. tensor veli palatini= (Fig. 66, _d_, _d′_, page 112).
_Origin_ from the ventral surface of the body of the sphenoid between the foramen ovale and the groove for the Eustachian tube. The muscle ends in a flat tendon which passes over the hamular process (3) of the pterygoid bone.
_Insertion_ by spreading out in the soft palate into an aponeurosis which joins the aponeurosis of the opposite muscle and lies between the mucous membrane of the mouth and that of the nose.
=M. levator veli palatini= (Fig. 66, _e_, _e′_).--A flat triangular muscle which lies within the tensor.
_Origin_ from the surface of the body of the sphenoid mediad of the groove for the Eustachian tube, from the styliform process of the bulla tympani, and in part from the Eustachian tube. The muscle passes caudad, and its fibres then diverge into the velum palatinum.
_Insertion_ into the velum palatinum, some of the fibres meeting in the middle line.
A number of other muscles have been described in the soft palate of the cat; they are, however, poorly developed and not easily distinguished. For an account of these, see Stowell, Proceedings of the Am. Soc. of Microscopists, 1889.
2. =The Pharynx.=--At the caudal end of the mouth cavity the passage for the food and that for the air cross; at the cranial end the food-passage (mouth) is ventral, the respiratory passage (nasal cavity) dorsal. Farther caudad the food-passage (œsophagus) is dorsal, while the respiratory passage (larynx and trachea) is ventral. In the region of crossing there is therefore for a certain distance a common passageway for food and air, and this is known as the =pharynx=. It extends from the isthmus faucium, at the free caudal margin of the soft palate, to the beginning of the œsophagus, at the dorsal or caudal margin of the opening of the larynx. The dorsal wall of the pharynx is separated from the base of the skull and the centra of the cervical vertebræ only by intervening muscles (=longus capitis=, =levator scapulæ ventralis=, and =longus colli=, Fig. 72, page 143). Its lateral and ventral walls are supported by the hyoid bone and the cartilages of the larynx.