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Oesophagus - Anatomy & Physiology (view source)
Revision as of 10:49, 2 July 2008
, 10:49, 2 July 2008no edit summary
The oesophagus is devided into cevical, thoracic and abdominal sections.
The oesophagus is devided into cevical, thoracic and abdominal sections.
==Functional Anatomy==
==Functional Anatomy==
*Different proportions of striated muscle across the species
-Dog and ruminant = 100%
-Cat = 80% (rostral)
-Horse = 65% (rostral)
-Pig = 33% (rostral)
==Histology==
==Histology==
*Stratified squamous epithelium
*Mucosal folds for distension
*Degree of keratinisation depend on diet
*Lamina propria contains collagen and elastic fibres sparsely distributed
*Lamina muscularis is smooth muscle
*No glands in mucosa
*Mucous glands present in submucosa
*Inner circular layer of tunica muscularis thickens near gastric junction forming a sphincter
==Species Differences==
==Species Differences==
*Canid has no keratinisation
*Pig and horse have some keratinisation
*Ruminant has a lot of keratinisation
*Lamina muscularis absent cranially in pigs and dogs
*Lamina muscularis present caudally in pigs (very thick) and dogs (spirally arranged)
*Mucous glands abundant cranially but absent caudally in pig
*Mucous glands throughout in dog but more abundant caudally
*Mucous glands present in horse, cats and ruminants only at pharyngeal-oesophageal junction
*Thick and strong sphincter of tunica muscularis in dogs and pigs
*Ruminants, horse and pig have stratified squamous epithelium continuing from oesophagus into stomach. carnivores have an abrupt transition to columnar epithelium.
==Links==
==Links==