ANATOMY OF THE DIGESTIVE ORGANS 235. The DIGESTIVE ORGANS are the _Mouth_, _Teeth_,[7] _Sal´i-va-ry Glands_, _Phar´ynx_, _OE-soph´a-gus_, (gullet,) _Stom´ach_, _In-tes´tines_, (bowels,) _Lac´te-als_, (milk, or chyle vessels,) _Tho-rac´ic Duct_, _Liv´er_, and the _Pan´cre-as_, (sweetbread.) [7] See Chapter XII. -=-=-=-=-=-=-=-=-=-=-=-= 233. What is impressed upon the human system from its earliest existence? What maintains this change? 234. Has animal or vegetable food any resemblance to the different tissues of which it finally forms a part? By what organs is the first change in the food effected? 235-258. _Give the anatomy of the digestive organs._ 235. Name them. 236. Describe the mouth. -=-=-=-=-=-=-=-=-=-=-=-= MOUTH is an irregular cavity, which contains the instruments of mastication and the organs of taste. It is bounded in front by the lips; on each side by the internal surface of the cheeks; above, by the _hard palate_ (roof of the mouth) and teeth of the upper jaw; below, by the tongue and teeth of the lower jaw; behind, it is continuous with the pharynx, but is separated from it by a kind of movable curtain, called the _soft palate_. This may be elevated or depressed, so as to close the passage or leave it free. 237. The SALIVARY GLANDS are six in number; three on each side of the jaw. They are called the _pa-rot´id_, the _sub-max´il-la-ry_ and the _sub-lin´gual_. [Illustration: Fig. 58. A view of the salivary glands in their proper situations. 1, The parotid gland. 2, Its duct. 3, The submaxillary gland. 4, Its duct. 5, The sublingual gland, brought to view by the removal of a section of the lower jaw.] 238. The PAROTID GLAND, the largest, is situated in front of the external ear, and behind the angle of the jaw. A duct (Steno's) from this gland opens into the mouth, opposite the second molar tooth of the upper jaw. -=-=-=-=-=-=-=-=-=-=-=-= 237. How many glands about the mouth? Give their names. What does fig. 58 represent? 238. Describe the parotid gland. -=-=-=-=-=-=-=-=-=-=-=-= 239. The SUBMAXILLARY GLAND is situated within the lower jaw, anterior to its angle. Its excretory duct (Wharton's) opens into the mouth by the side of the _fræ´num lin´guæ_, (bridle of the tongue.) 240. The _SUBLINGUAL GLAND_ is elongated and flattened, and situated beneath the mucous membrane of the floor of the mouth, on each side of the frænum linguæ. It has seven or eight small ducts, which open into the mouth by the side of the bridle of the tongue. _Observation._ In the "mumps," the parotid gland is diseased. The swelling under the tongue called the "frog" is a disease of the sublingual gland.