The tongue, a muscular organ in the mouth, provides the sense of taste and assists in chewing, swallowing, and speaking. It is firmly anchored by connective tissues to the front and side walls of the pharynx, or throat, and to the hyoid bone in the neck.
The mammalian tongue is divided into two parts by a V—shaped groove, the terminal sulcus. At the apex of this V is a small blind pit, the foramen cecum. The larger part, or body, of the tongue belongs to the floor of the mouth, whereas the root forms the front wall of the oral pharynx. The body of the tongue is separated from the teeth and gums by a deep groove. A midline fold, the frenu—lum, is near he tip on the undersurface. The upper surface of the body, called the dorsum, has a velvety appearance because of filiform papillae. Distributed among these are occasional larger, rounded fungiform papillae and some large conical papillae. Immediately in front of the groove separating the body of the tongue from the root is a series of still larger vallate papillae arranged in a V—shaped row. The apex of the V points down the throat. Posteriorly along each side of the body of the tongue and near the root, is a series of parallel folds constituting the foliate papillae. The surface of the root of the tongue, which belongs to the pharynx, has no papillae but bears nodules containing lymphoid tissue.
New words
buccal – относящийся ко рту или щеке
palatine – небный
salivary glands – слюнные железы
parotid gland – околоушная железа
sublingual – подязыковой
43. The digestive tract structure
The gastrointestinal tract and associated organs are collectively called the digestive system. This system is responsible for receiving food and breaking it down by using enzymes from the glands and by the movement of the various parts of the intestinal tract; for absorption of these components into the blood; and for eliminating undigested food and certain metabolic wastes from the body. The alimentary canal extends from the mouth to the anus. It is a long tube varying in size and shape depending on what function the particular part performs. The tract has a very good blood sup ply, because food, once it is broken down, has to be absorbed into the bloodstream. The mouth contains the tongue and the teeth and communicates with the salivary glands situated round it. Behind the nose and mouth is the pharynx. Leading from the pharynx is a mus cular tube called the esophagus which passes down the thoracic cavity to the stomach. The stomach lies below the diaphragm in the upper left side, of the abdominal cavity. The opening into the small intestine is called the pylorus and is closed by the pyloric sphincter. The small intestine is a muscular tube coiled up in the abdominal ca vity. It is divided into three parts; the duodenum, the jejunum, and the ilium. The large intestine, also a muscular tube but with wider lumen than the small intestine, is often called the colon. It is divided into several different parts: the, cecum, the ascending colon, the transverse colon, the descending colon, the rectum and the anal canal. The glands belonging to the digestive system are the salivary glands, the liver and the pancreas.