The salivary glands produce saliva, which keeps the mouth and other parts of the digestive system moist. It also helps break down food and lubricates the passage of food down from the oro-pharynx to the esophagus to the stomach.

There are three main pairs of salivary glands: the parotid, the submandibular and the sublingual glands. There are also many small glands in the tongue, cheeks, lips and palate.

Histology

Two types of epithelial cells in salivary glands produce either mucous, or serous secretions. The sublingual gland produces serous secretions, whereas the parotid gland produces mucous secretions. The submandibular gland contains a mixture of both types of cells, and produces a mixture of the two liquids.

Location of the glands

There are three salivary glands:

• The parotid gland is located near the ear (par- = next to, -otid = ear), and is the largest of the salivary glands.
• The sublingual gland lies underneath the tongue.
• The submandibular gland is a U-shaped structure, and lies beneath the ramus of the mandible (the angle of the chin).

Role in disease

See mumps (parotiditis epidemica) and Sjögren syndrome. Tumors of the salivary glands may occur. These are usually benign, but may be malignant.