Changes

==Physiology==

==Physiology==

* In most animals, after swallowing, food leaves the [[Oesophagus - Anatomy & Physiology|oesophagus]] and enters the [[Monogastric Stomach - Anatomy & Physiology|stomach]]. In ruminants, food enters the [[Abomasum - Anatomy & Physiology|abomasum]] after fermentation in the forestomach.  

In most animals, after swallowing, food leaves the [[Oesophagus - Anatomy & Physiology|oesophagus]] and enters the [[Monogastric Stomach - Anatomy & Physiology|stomach]]. In ruminants, food enters the [[Abomasum - Anatomy & Physiology|abomasum]] after fermentation in the forestomach. The [[Monogastric Stomach - Anatomy & Physiology|stomach]] acts as a reservoir in which a semi-solid mass (chyme) is formed from the ingested food before passing into the [[Duodenum - Anatomy & Physiology|duodenum]]. With the exception of water, little absorption occurs in the [[Monogastric Stomach - Anatomy & Physiology|stomach]]. Gastric juice is highly acidic, and contains: HCl, produced by the parietal cells which maintains gastric pH at 2, which denatures protein. It also contains pepsin, derived from pepsinogen, produced by zymogen cells. The action of HCl facilitates this. Surface epithelial cells and mucous neck cells produce mucus which forms an alkaline sheet over the epithelial surface. This provides protection from the gastric juice. The cells of the mucosa are renewed at different rates. This is an important considerination in the pathogenesis of certain gastric diseases. Surface epithelial cells and mucous neck cells are replaced about every 3 days. Parietal cells and zymogen cells are produced at a slower rate; the parietal cells have a half-life of 23 days.  

* The [[Monogastric Stomach - Anatomy & Physiology|stomach]] acts as a reservoir in which a semi-solid mass (chyme) is formed from the ingested food before passing into the [[Duodenum - Anatomy & Physiology|duodenum]].

* With the exception of water, little absorption occurs in the [[Monogastric Stomach - Anatomy & Physiology|stomach]].

* Gastric juice is highly acidic, and contains:

** HCl, produced by the parietal cells

*** Maintains gastric pH at 2, which denatures protein.

** Pepsin, derived from pepsinogen, produced by zymogen cells

*** The action of HCl facilitates this.  

* Surface epithelial cells and mucous neck cells produce mucus which forms an alkaline sheet over the epithelial surface.  

** Provides protection from the gastric juice.  

* The cells of the mucosa are renewed at different rates. This is an important considerination in the pathogenesis of certain gastric diseases.

** Surface epithelial cells and mucous neck cells are replaced about every 3 days.

** Parietal cells and zymogen cells are produced at a slower rate; the parietal cells have a half-life of 23 days.  

==Defence Mechanisms==

==Defence Mechanisms==

#* Continuous movement discourages persistence of insult at mucosa.

#* Continuous movement discourages persistence of insult at mucosa.

==Test Yourself with Flashcards==

'''Test Yourself with [[The Stomachs of the Ruminant - Anatomy & Physiology - Flashcards|Ruminant Stomachs Flashcards]]'''

 

[[The Stomachs of the Ruminant - Anatomy & Physiology - Flashcards|Ruminant Stomachs Flashcards]]

[[Category:Stomach - Anatomy & Physiology]]

[[Category:Stomach - Anatomy & Physiology]]

[[Category:Alimentary System - Cattle]]

[[Category:Alimentary System - Cattle]]

[[Category:To Do - A&P]]

[[Category:To Do - AimeeHicks]]