ANATOMY

They lie superior to Digastric Muscles and divided into superficial and deep lobes which are separated by Mylohyoid Muscle. Secretions are secreted through Submandibular or Wharton duct. The excretory ducts are crossed by Lingual Nerve and drain into Sublingual Caruncles on both sides of Lingual Frenulum with Bartholin or Sublingual duct.

HISTOLOGY

Lobes contain smaller Lobules which have Adenomeres (secretory units of glands). Each of these Adenomeres contains one or more Alveoli, clusters of cells that secrete their products in the duct. These Alveoli are made of Serous or Mucous cells. Mucous cells are most active in Submandibular glands so the major product of this gland is secretion of saliva which is mucous in nature. Mucous cells secrete Mucin which helps in lubricating the food bolus for it to pass through Esophagus easily.

BLOOD SUPPLY

The blood supply to these glands is through Facial and Lingual Arteries.

INNERVATION

Their secretions are regulated directly through Parasympathetic Nervous System and indirectly through Sympathetic Nervous System.

Increase Parasympathetic activity increases secretions of saliva.

Increase Sympathetic activity reduce blood flow of glands causing the volume of fluid in salivary secretions decrease in volume producing an enzyme rich mucus saliva.

DEVELOPMENT

These glands develop late in the sixth week of prenatal development.

PATHOLOGY

Submandibular gland accounts for 80% of all Salivary duct Calculi (Salivary Stones) due to different nature of saliva it produces.