SALIVARY GLANDS
There are major and minor salivary glands. Major glands are parotid glands (located in the temporal region and having Stensen duct), submandibular glands (located in the submandibular triangle of the neck and having Wharton duct), sublingual glands (lying inferior to the tongue, having a number of small excretory ducts). Minor salivary glands are located in the submucosal layer of the oral cavity. Most minor salivary glands are located in the submucosa of lips, hard and soft palate.
Parotid glands are the largest pair of all. The excretory duct has a valve that regulates the release of secret. Parotid glands produce serous secretion. Its amount depends on the individual body, sight and smell of food. Cells of the parotid gland take part in removing toxins and drugs from the body. Parotid glands are endocrine glands, as their secret parotin participates in mineral and protein metabolism.
Sensitive, sympathetic and parasympathetic nerves take part in the inner-vation of the parotid salivary glands. Facial nerves pass through the parotid gland.
Submandibular salivary gland produces serous secretion. Excretory ducts open on the sublingual gland papillae, on the floor of the mouth. The gland is supplied with blood by mental and lingual arteries. The submandibular gland is innervated by branches of submandibular ganglion.
COMPOSITION OF SALIVA AND ORAL FLUID
Saliva is the secretion of the salivary glands released in the mouth. In the oral cavity there is a biological fluid called oral fluid. Oral fluid is a mixture of saliva, bacteria and its metabolites, gingival fluid, desquamated epithelium, leukocytes, and food remnants.
In adults salivary glands produce about 1500-2000 ml of saliva per day. The rate of secretion depends on age (in older people the rate of secretion is reduced), nerve status, food stimulus. During sleep, the rate of saliva secretion decreases 8-10 times. The dentist deals with the oral fluid, as it is the environment for oral organs and tissues.