Saliva plays an important role in the process of digestion. Digestion is initiated in the presence of saliva.
In all mammals, the salivary glands functions as an exocrine gland, which produces saliva through a system of ducts. Among all other mammals, humans have hundreds of salivary glands and are present within the mouth. The basic secretion units of salivary glands are called acini and are composed of clusters of cells.
Glands that secrete saliva
The many minute glands that secrete saliva, there are three major pairs of salivary glands. They are as follows
- The parotid
- The submandibular
- The sublingual glands
The parotid glands, the largest of the pairs, are located at the side of the face, below and in front of each ear. The parotid glands are enclosed in sheaths that limit the extent of their swelling when inflamed, as in mumps.
The submandibular glands, which are rounded in shape, lie near the inner side of the lower jawbone, in front of the sternomastoid muscle (the prominent muscle of the jaw).
The sublingual glands lie directly under the mucous membrane covering the floor of the mouth beneath the tongue.