Salivary Glands Overview - Anatomy & Physiology

Introduction

The oral cavity is drained by numerous salivary glands. The saliva secreted keeps the mouth moist and facilitates mastication by lubricating the passage of the bolus.

Salivary glands are present in the cheek, tongue, lips, oesophagus, soft palate and pharynx but the major salivary glands are located further away from the oral cavity and function through connective ducts.

Saliva provides digestive enzymes, is a route of excretion of substances which accumulate on the teeth and provides lubricative and also cleansing functions. Salivary glands can produce a serous secretion, a mucous secretion or both.

Types of Salivary Glands

Parotid & Mandibular Salivary Gland - Copyright Nottingham 2008

Major Salivary Glands

Parotid (glandula parotis), Mandibular (glandula mandibularis), Sublingual (glandula sublinguales) and Zygomatic (glandula zygomatica).

Minor Salivary Glands

Labial, Lingual, Buccal and Palatine.

Salivary Glands Labelled (Dog) - Copyright C.Clarkson and T.F.Fletcher University of Minnesota

Innervation

The salivary glands are innervated by sympathetic- Vasoconstriction occurs and the flow of saliva is decreased.

The salivary glands are also innervated by parasympathetic (most important)- They travel from the brainstem by the facial (CN VII) and glossopharyngeal (CN XI) then into branches of the trigeminal nerve (CN V). The flow of salivary fluid increases and vasodilation occurs.

The main nerves are the occulomotor (CN III), facial (CN VII), glossopharyngeal (CN IX) and vagus (CN X).

Saliva

Saliva is mainly water and contains amylase for carbohydrate digestion, salt- mainly sodium bicarbonate, mucin, electrolytes, antimicrobial agents and lingual lipase.

Species Differences

Salivary Glands of cow, horse, pig and dog - Copyright prof. Pat Mccarthy

Equine

Produce up to 40L per day.

Bovine

Produce 110-180L per day.

Porcine

Produce up to 15L per day.

Links

Click here for information on Salivary Glands Pathology

Salivary Glands Overview - Anatomy & Physiology Learning Resources
Flashcards Test your knowledge using flashcard type questions	Salivary Glands
PowerPoint Selection of relevant PowerPoint tutorials	Oral Cavity Histology, see part 2 for salivary glands