| 单词 | parotid glands |
| 释义 | parotid glandsparotid glands:see salivary glandssalivary glands, in humans, three pairs of glands that secrete the alkaline digestive fluid, saliva, into the mouth. Most animals have salivary glands that resemble those in humans; however, in some animals these glands perform other functions. ..... Click the link for more information. . parotid glandsparotid[pah-rot´id]The parotid glands are made up of groups of cells clustered around a globular cavity, resembling a bunch of grapes. Small ducts draining each cavity join the ducts of neighboring cavities to form large ducts, which in turn join the parotid duct. From the system of ducts flows the thin, watery secretion of the parotid glands called saliva, which plays an important role in the process of digestion. As food is chewed the saliva with which it is mixed and moistened makes it possible for the food to be reduced to a substance that can be swallowed. Controlled by the autonomic nervous system, the secretion of the salivary glands begins whenever the sensory nerves of the mouth, or in some cases nerves located elsewhere in the body, are stimulated. Salivation may be an involuntary reflex, as when food or even inedible material placed in the mouth starts the flow of the secretion from the glands, or it may be a conditioned reflex, as when the flow is started by the sight, smell, or thought of food. Swelling and tenderness may also result from infections caused by other viruses or bacteria in the glands. Less often, these symptoms indicate a blockage of a duct by either infection or a calculus, in which case the swelling is likely to fluctuate, especially at mealtimes. Though stubborn or recurring cases sometimes require surgery, stones often can be removed by massage. For infections, antibiotics and warm compresses are the usual treatment. Occasionally additional glandular masses grow in or near a parotid gland. The majority of such growths are mixed tumors, so called because they contain cartilage or other material as well as the usual glandular material. Usually they are benign; occasionally they may be malignant and require surgery. parotid glandsThe largest of the three pairs of SALIVARY GLANDS. Each parotid is situated over the angle of the jaw, below and in front of the lower half of the ear and has a duct running forward through the cheek to open on the inside of the mouth at about the level of the upper molar teeth. |
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