Parotid Gland - Anatomy & Physiology

Overview

Parotid Salivary Gland - Copyright Nottingham 2008

The parotid salivary gland produces a serous secretion. It is moulded around the base of the auricular cartilage of the ear. It is enclosed within facial covering.

Trabeculae divide the gland into lobules. Major ducts run within trabeculae and merge to form a single duct. The duct opens in the vestibule opposite the 4th upper premolar (Not all species).

The parotid gland is innervated by the glossopharyngeal nerve (CN IX) via the trigeminal branch. (CN V)

Development

There is an intercalated duct and cuboidal cells. This becomes a striated duct, the cuboidal cells develop with mitochondria in the base. The duct develops into an interlobular duct. The cells become stratified columnar cells. The stratified squamous epithelium then becomes continuous with the epithelium lining of the oral cavity.

Species Differences

Parotid Duct (Dog) - Copyright RVC

Carnivores

There is some mucous secretion in the cat and dog. The duct is superficial in the dog. The duct runs across masseter muscle in carnivores.

Herbivores

It is a larger gland with a higher flow rate in herbivores to lubricate and soften the food. The duct is superficial in small ruminants. The parotid gland extends rostrally over the masseter muscle, ventrally to the angle of the jaw and caudally towards the atlantal fossa. The duct runs ventrally in herbivores below the mandible (facial groove in horses) before entering the oral cavity at the rostral margin of the masseter muscle.

Equine

The gland overlies the gutteral pouch.

Links

Test yourself with the Salivary Glands Flashcards

Click here for information onhistology

Video links:

Pot 258 Lateral section through the head of a dog