Salivary Glands - Anatomy & Physiology

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Introduction

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

Salivary gands 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

Major Salivary Glands

• Parotid (glandula parotis)

• Mandibular (glandula mandibularis)

• Sublingual (glandula sublinguales)

• Zygomatic (glandula zygomatica)

Minor Salivary Glands

• Labial

• Lingual

• Buccal

• Palatine

Innervation

• Sympathetic

   -Vasoconstriction occurs
   -Flow of saliva is decreased

• Parasympathetic (most important)

   -Travel from the brainstem by the facial (CN VII) and glossopharyngeal (CN IX) then into
    branches of the trigeminal nerve (CN V)
   -Flow of salivary fluid increases 
   -Vasodilation occurs

• Main nerves are occulomotor (CN III), facial (CN VII), glossopharyngeal (CN IX) and vagus (CN X)

Saliva

• Mainly water

• Amylase for carbohydrate digestion

• Salt- mainly sodium bicarbonate

• Mucin

• Electrolytes

• Antimicrobial agents

• Lingual lipase

Species Differences

Equine

• Horses produce up to 40L per day

Bovine

• Cows produce 110-180L per day

Porcine

• Pigs produce up tp 15L per day

Links

Salivary Glands Pathology