Exam 3 Review:  Chapter 23:  Oral Cavity IV - Salivary Glands

salivary glands - Any of the various exocrine glands which discharge into the oral cavity the fluid secretions which form saliva; the main glands in humans are the parotid glands, the sublingual glands, and the submandibular glands; they also produce the digestive enzyme, salivary amylase, which breaks down carbohydrates.

buccal glands - Any of the small mucous glands found in the mucous membrane lining the cheeks; they make a minor contribution to the composition of saliva.

parotid glands - The largest pair of salivary glands, situated on each side of the face below and in front of the ear, composed primarily of serous acini; their serous secretions make a major contribution to the composition of saliva; their secretions are delivered to the buccal cavity by the parotid ducts.

submandibular glands - The second largest pair of salivary glands, situated inside of and near the lower edge of each side of the mandible, composed of both serous and mucous acini; their secretions make a major contribution to the composition of saliva; their secretions are delivered to the floor of the mouth under the tongue by large ducts.

sublingual glands - The small pair of salivary glands situated on each side of the mouth lying beneath the mucous membrane in a fossa in the mandible near the symphysis and under the tongue, composed of both serous and mucous acini; their secretions make a minor contribution to the composition of saliva; their secretions are delivered to the floor of the mouth under the tongue by a series of small ducts.

saliva - The slightly alkaline secretion of the various salivary glands with contributions from some specialized cells of the lining epithelium of the oral cavity, consisting of water, mucin, other protective proteins, salts, and two digestive enzymes, salivary amylase -- splits starch, and lingual lipase -- splits lipids; this fluid moistens, lubricates and softens ingested food, and begins the chemical digestion of starches and  lipids.

salivation - The process of secreting saliva from the various salivary glands and small mucous glands of the oral cavity; it may be stimulated by the thought, taste or smell of foods, and by the actual masticating of food; it is coordinated by parasympathetic impulses of the ANS and inhibited by sympathetic impulses from the ANS during "fight-or-flight" emergencies.

salivary amylase - The enzyme, produced by the salivary glands, which is present in saliva and catalyzes the hydrolysis of starch to sugar, beginning the chemical digestion of complex carbohydrates; it works well in the slightly alkaline oral cavity but becomes denatured and ineffective in the highly acidic environment of the stomach.

12.  the functions of the salivary glands.

         (1)  initiate chemical digestion of starch with salivary amylase
         (2)  secrete mucous secretions, i.e., saliva, to lubricate the oral cavity and associated structures and to moisten, and therefore, assist in the mechanical digestion of foodstuffs
         (3)  secrete HCO3- (bicarbonate) ions to buffer the oral cavity to facilitate salivary amylase activity and to resist acid attack on tooth structure by oral normal flora (tooth decay)
         (4)  secrete lysozyme, IgA class antibodies, and other resistance factors to limit the growth of or destroy microbes ingested with food
         (5)  secrete electrolytes; Ca⁺⁺ and HPO₄^-2 ions assist in maintaining the integrity of tooth enamel; lead ions may be excreted as waste (but will normally be swallowed and reabsorbed)