Parotid Gland - Anatomy & Physiology

From WikiVet English
Revision as of 00:19, 3 July 2010 by A.allison (talk | contribs) (Text replace - '|maplink = Alimentary (Concept Map)- Anatomy & Physiology' to '|maplink = ')


Jump to navigation Jump to search
Anatomy and PhysiologyWikiAnt and Phys Banner.png
ALIMENTARY SYSTEM
MAJOR SALIVARY GLANDS



Parotid Salivary Gland

Parotid Salivary Gland - Copyright Nottingham 2008
  • Enclosed within facial covering
  • Trabeculae divide gland into lobules
  • Major ducts run within trabeculae and merge to form a single duct
  • Duct opens in vestibule opposite 4th upper premolar (Not all species)
  • Innervated by glossopharyngeal (CN IX) via trigeminal branch (CN V)

Development

1. Intercalated duct. Cuboidal cells.

2. Striated duct. Cuboidal cells with mitochondria in base.

3. Interlobular duct. Columnar to stratified columnar cells.

4. Stratified squamous epithelium continuous with epithelium lining oral cavity


Histology

  • Basophilic endoplasmic reticulum
  • Stratified squamous epithelium
  • Tubulo-acinar gland
  • Acinar cells surrounded by myoepithelial cells and basement membrane


Species Differences

Parotid Duct (Dog) - Copyright RVC

Carnivores

  • Some mucous secretion in cat and dog
  • Duct is superficial in dog
  • Duct runs across masseter muscle in carnivores

Herbivores

  • Larger gland and higher flow rate in herbivores to lubricate and soften food
  • Duct is superficial in small ruminants
  • Parotid gland extends rostrally over masseter muscle, ventrally to angle of jaw and caudally towards atlantal fossa
  • 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

Links

Video Pot 258 Lateral section through the head of a dog