Anatomy and Function of Salivary Glands - SEY PHARMA

Salivary glands release their secretions into ducts that lead to the mouth. There are three main pairs: the parotid glands, the submandibular glands and the sublingual glands. There are also numerous smaller salivary glands scattered around the mouth.

Parotid glands

These are situated one on each side of the face just below the external acoustic meatus. Each gland has a parotid duct opening into the mouth at the level of the second upper molar tooth.

Submandibular glands

These lie one on each side of the face under the angle of the jaw. The two submandibular ducts open on the floor of the mouth, one on each side of the frenulum of the tongue.

Sublingual glands

These glands lie under the mucous membrane of the floor of the mouth in front of the submandibular glands. They have numerous small ducts that open into the floor of the mouth.

fig: Three Salivary Glands

Structure of the salivary glands

The glands are all surrounded by a fibrous capsule. They consist of a number of lobules made up of small acini lined with secretory cells. The secretions are poured into ductules that join up to form larger ducts leading into the mouth. Arterial supply is by various branches from the external carotid arteries and venous drainage is into the external jugular veins.

Composition of saliva:

Saliva is the combined secretions from the salivary glands and the small mucus-secreting glands of the oral mucosa. About 1.5 litres of saliva is produced daily and it consists of : water, mineral salts, salivary amylase; a digestive enzyme, mucus, antimicrobial substances; immunoglobulins and the enzyme lysozyme.

Functions of saliva :

Saliva keeps the mouth moist and facilitates speech.
Saliva helps in mastication of food and forms the bolus.
Saliva dilutes, hot and pungent substances and prevents injury to the mouth. It also acts as solvent.
Saliva removes food particles and thus prevents the growth of microbes. It also acts as an antiseptic to the mouth.
Maltose changes maltose to glucose to some extent. So, if one chews food well he enjoys a sweet taste of glucose.
Saliva helps in excretion of heavy metals, urea and certain other drug.
Saliva helps in maintenance of water balance and is secreted through the nervous system mechanism.
Saliva cts as buffer by maintaining the level of bicarbonate and phosphate in the blood.