SALIVARY GLANDS. Under this name we designate three pairs of glands—the parotid, the til.hinixilla•y, and the sublin Dial each gland having an efferent duct, which conveys the glaninktr secretions into the mouth, where, when mixed with the mucus secreted by the follicles of the mucous membrane lining the mouth, they constitute the ordinary or mixed saliva.
The tarot id [land, so called from the Greek words pare, near, and 0128, the ear, is the largest of the three glands occurring on either side. It lies upon the side of the face imm-diately in front of the external ear, rind weighs from half an ounce to an ounce. Its duet is about two inches and a half in length. and opens into the month by a small orifice opposite the second molar tooth of the upper jaw. The walls of the duct are dense a tut somewhat thick, and the caliber is about that of a crow-quill.
The subega.riliary gland is situated, as its name implies, below the jawbone. and is placed at nearly equal distances from the parotid and sublingual glands. Its duct is about two inches in length. and opens by a narrow orifice on the top of a papilla, at the side of the, f rem um of the tongue.
The sublin ['real filmed is situated, as its name implies, tinder the tongue, each gland lying ou either side of the frceP-tm of the tongue. It has a number of excretory ducts, which open separately into the mouth.
The minute structure of the parotid gland is described in the article GLANDS, and the other salivary glands are similarly constituted. True salivary glands exist in all mam mals, except the cetacea, in birds, and reptiles (including amphibians), but not in fishes; and glands discharging a similar function occur iu insects, many mollusks, etc. The chemical and physical characters of the saliva are sufficiently described in the article DtuEsTiox.
The most common disease of the parotid gland is a specific inflammation, which has been already in the article Mumrs. The term parotid (suitors is given to
tumors of various kinds occurring in front of the ear and over the parotid gland, With regard to surgical interference, Liston recommends that "if there be reason to suspect that the disease is of a malignant nature, and not thoroughly limited by a cellular cyst, no interference is admissible; iY, on the contrary, it he at all movable, has advanced slowly, possesses a smooth surface, and is hir111, then an operation may be contemplated." Certain functional disorders of the salivary glands require notice, of which the most important is that known as sctUration (q.v.), or ptyalistn, which consists in it 100th of Deficient secretion is indicated by clamminess or dryness of the month. and is commou in low forms of fever. It is important as indiem big the condition of the system, and seldom requires treatment. If it should occur as an original affection, it must be treated by local sialugogues (q.v.), such as liquorice. horse-radish, pellitory, etc. Alteration, qf the satira is not untrcquent in disease. For example, it sometinws its alkaline character, and becomes acid, as in acute rheumatism, dia betes, etc. ; whilst in other cases, it becomes so fetid as to be a source of annoyance both to the patient and his friends, as, for example, in scurvy, various forms of dyspepsia, calivatim], etc. '1'1e undue acidity may be corrected by the administration of carbonate or bicarbonate of soda, while the lam may be relieved by attention to diet, and by the use, both local and general, of creosote, nitro-muriatic acid, charcoal, chlorate of potash. etc.
Ordinary inflammation of these glands (distinct from mumps) may proceed from cold or local injury, but it is often produced by decayed teeth.