|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
|collections in the vicinity of the auditory tubes, while the ring is completed behind by the pharyngeal tonsil on the posterior wall of the pharynx. In the intervals between these main masses are smaller collections of adenoid tissue.|
Structure (Fig. 1027).The follicles of the tonsil are lined by a continuation of the mucous membrane of the pharynx, covered with stratified squamous epithelium; around each follicle is a layer of closed capsules consisting of lymphoid tissue imbedded in the submucous tissue. Lymph corpuscles are found in large numbers invading the stratified epithelium. It is probable that they pass into the mouth and form the so-called salivary corpusles. Surrounding each follicle is a close plexus of lymphatics, from which the lymphatic vessels pass to the deep cervical glands in the neighborhood of the greater cornu of the hyoid bone, behind and below the angle of the mandible.
Vessels and Nerves.The arteries supplying the tonsil are the dorsalis linguæ from the lingual, the ascending palatine and tonsillar from the external maxillary, the ascending pharyngeal from the external carotid, the descending palatine branch of the internal maxillary, and a twig from the small meningeal.
| The veins end in the tonsillar plexus, on the lateral side of the tonsil.|
| The nerves are derived from the sphenopalatine ganglion, and from the glossopharyngeal.|
Palatine Aponeurosis.Attached to the posterior border of the hard palate is a thin, firm fibrous lamella which supports the muscles and gives strength to the soft palate. It is thicker above than below, where it becomes very thin and difficult to define. Laterally it is continuous with the pharyngeal aponeurosis.
Muscles of the Palate.The muscles of the palate (Fig. 1028) are:
|Levator veli palatini.||Glossopalatinus.|
|Tensor veli palatini.||Pharyngopalatinus.|
| The Levator veli palatini (Levator palati) is a thick, rounded muscle situated lateral to the choanæ. It arises from the under surface of the apex of the petrous part of the temporal bone and from the medial lamina of the cartilage of the auditory tube. After passing above the upper concave margin of the Constrictor pharyngis superior it spreads out in the palatine velum, its fibers extending obliquely downward and medialward to the middle line, where they blend with those of the opposite side.|
| The Tensor veli palatini (Tensor palati) is a broad, thin, ribbon-like muscle placed lateral to the Levator veli palatini. It arises by a flat lamella from the scaphoid fossa at the base of the medial pterygoid plate, from the spina angularis of the sphenoid and from the lateral wall of the cartilage of the auditory tube. Descending vertically between the medial pterygoid plate and the Pterygoideus internus it ends in a tendon which winds around the pterygoid hamulus, being retained in this situation by some of the fibers of origin of the Pterygoideus internus. Between the tendon and the hamulus is a small bursa. The tendon then passes medialward and is inserted into the palatine aponeurosis and into the surface behind the transverse ridge on the horizontal part of the palatine bone.|
| The Musculus uvulæ (Azygos uvulæ) arises from the posterior nasal spine of the palatine bones and from the palatine aponeurosis; it descends to be inserted into the uvula.|
| The Glossopalatinus (Palatoglossus) is a small fleshy fasciculus, narrower in the middle than at either end, forming, with the mucous membrane covering its surface, the glossopalatine arch. It arises from the anterior surface of the soft palate, where it is continuous with the muscle of the opposite side, and passing downward, forward, and lateralward in front of the palatine tonsil, is inserted into the side of the tongue, some of its fibers spreading over the dorsum, and others passing deeply into the substance of the organ to intermingle with the Transversus linguæ.|
| The Pharyngopalatinus (Palatopharyngeus) is a long, fleshy fasciculus narrower in the middle than at either end, forming, with the mucous membrane covering