Difference between revisions of "Reticulum - Anatomy & Physiology"

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|backcolour =BCED91
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|linkpage =Alimentary - Anatomy & Physiology
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|linktext =Alimentary System
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|maplink = Alimentary (Concept Map)- Anatomy & Physiology
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|pagetype =Anatomy
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|subtext1=STOMACH AND ABOMASUM
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|sublik1=Stomach and Abomasum - Anatomy & Physiology
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<br>
 
==Introduction==
 
==Introduction==
  
−
The reticulum is the second chamber of the ruminant stomach. It has regular contractions which precede the biphasic ruminal contraction for digestion of food particles. Mechanical digestion and microbial fermentation occur to breakdown food particles for absorption. [[Volatile Fatty Acids|Volatile fatty acids]] are the major product of ruminant digestion.
+
The reticulum is the second chamber of the ruminant stomach. It has regular contractions which precede the biphasic ruminal contraction for digestion of food particles.
 +
 
 +
Mechanical digestion and microbial fermentation occur to breakdown food particles for absorption. [[Volatile Fatty Acids - Anatomy & Physioogy|Volatile fatty acids]] are the major product of ruminant digestion.
 +
 
  
 
==Structure==
 
==Structure==
  
−
[[Image:Reticulum Anatomy Sheep.jpg|thumb|right|250px|Reticulum Anatomy (Sheep) - Copyright RVC 2008]]
+
[[Image:Reticulum Anatomy Sheep.jpg|thumb|right|150px|Reticulum Anatomy (Sheep) - Copyright RVC 2008]]
 +
*Covered by greater omentum
 +
 
 +
*The rumino-reticular fold often gets object lodged. When the [[The Rumen - Anatomy & Physiology|rumen]] contracts, the object can be pushed through the reticulum wall into the [[Structure of the Heart - Anatomy & Physiology#Pericardium|pericardium]] and [[Heart - Anatomy & Physiology|heart]].
 +
 
 +
*Opening at the cardia into both the reticulum and the [[The Rumen - Anatomy & Physiology|rumen]] is called the reticuluar groove (see [[Oesophageal groove|oseophageal groove]]). The reticular groove also opens into the [[The Omasum - Anatomy & Physiology|omasum]].
 +
 
 +
*Cranial to the [[The Rumen - Anatomy & Physiology|rumen]]
 +
 
 +
*Ribs 6-8
  
−
The reticulum is covered by greater omentum. The rumino-reticular fold often gets objects lodged. When the [[Rumen - Anatomy & Physiology|rumen]] contracts, the object can be pushed through the reticulum wall into the [[Heart Structure - Anatomy & Physiology#Pericardium|pericardium]] and [[Heart - Anatomy & Physiology|heart]].
+
*From cardia to the diaphragm
  
−
Opening at the cardia into both the reticulum and the [[Rumen - Anatomy & Physiology|rumen]] is called the reticular groove (see [[Oesophageal Groove|oseophageal groove]]). The reticular groove also opens into the [[Omasum - Anatomy & Physiology|omasum]].
+
*Lies above the xiphoid process of the sternum
  
−
The reticulum is cranial to the [[Rumen - Anatomy & Physiology|rumen]] at ribs 6-8. It is located from cardia to the diaphragm. It lies above the xiphoid process of the sternum. Serosa covers the surface.
+
*Serosa covers the surface
  
 
==Function==
 
==Function==
  
−
The functions of the reticulum include waste removal and movement. Simpler products of digestion are assimilated directly, others continue down the digestive tract for further digestion.
+
*Waste removal
 +
 
 +
*Movement
 +
 
 +
*Simpler products of digestion are assilimated directly, others continue down the digestive tract for further digestion
 +
 
 +
*See [[Rumination - Anatomy & Physiology|rumination]]
 +
 
 +
*See [[Eructation - Anatomy & Physiology|eructation]]
  
−
See [[Rumination|rumination]] and [[Eructation|eructation]].
 
  
 
==Ruminoreticular contraction==
 
==Ruminoreticular contraction==
  
−
[[Image:Contractions of the ruminoreticulum diagram.jpg|thumb|right|250px|Diagram of the contractions of the ruminoreticulum - Copyright RVC 2008]]
+
[[Image:Contractions of the ruminoreticulum diagram.jpg|thumb|right|150px|Diagram of the contractions of the ruminoreticulum - Copyright RVC 2008]]
 +
*Primary mixes food
 +
**Mixing cycle of ruminoreticulum
 +
**2 contractions of the reticulum (2nd most powerful) which continues over the [[The Rumen - Anatomy & Physiology|rumen]]
 +
**Ingesta flows from the reticulum to cranial ruminal sac to reticulum (or ventral sac)
 +
**Every 60 seconds
 +
 
 +
*Secondary lets gas out
 +
**See [[Eructation - Anatomy & Physiology|eructation]]
 +
**Ingesta flows from ventral blind sac to dorsal blind sac to dorsal sac ([[Eructation - Anatomy & Physiology|eructation]]) to ventral sac
  
−
The contractions have two main functions:
+
==Vasculature==
−
:Primary contraction mixes food by a ruminoreticuluar mixing cycle. There are 2 contractions of the reticulum (2nd most powerful) which continue over the [[Rumen - Anatomy & Physiology|rumen]]. Ingesta flows from the reticulum to cranial rumenal sac and then to reticulum (or ventral sac). It occurs every 60 seconds.
 
  
−
:The secondary contraction lets gas out (see [[Eructation|eructation]]). Ingesta flows from the ventral blind sac to the dorsal blind sac then to dorsal sac (eructation) and to the ventral sac.
+
*Cranial mesenteric artery
  
−
==Vasculature==
+
*Celiac artery
 +
 
 +
*Right and left ruminal arteries
  
−
The reticulum receives blood supply from the '''cranial mesenteric artery''', '''celiac artery''' and '''right and left ruminal arteries'''.
 
  
 
==Innervation==
 
==Innervation==
  
−
The reticulum is innervated by the '''dorsal vagus''' ([[Cranial Nerves - Anatomy & Physiology|CN X]]) (most important) and the '''ventral vagus''' nerve ([[Cranial Nerves - Anatomy & Physiology|CN X]]).
+
*Dorsal vagus ([[Nervous System - CNS - Anatomy & Physiology#Innervation - Cranial Nerves|CN X]]) (most important)
 +
 
 +
*Ventral vagus ([[Nervous System - CNS - Anatomy & Physiology#Innervation - Cranial Nerves|CN X]])
  
 
==Lymphatics==
 
==Lymphatics==
  
−
Numerous small lymph nodes are scattered in the grooves. The lymph drains to larger atrial nodes between the cardia and [[Omasum - Anatomy & Physiology|omasum]], then to the cistera chyli.
+
*Numerous small lymph nodes are scattered in the grooves
 +
 
 +
*The lymph drains to larger atrial nodes between the cardia and [[The Omasum - Anatomy & Physiology|omasum]], then to the cistera chyli
 +
 
  
 
==Histology==
 
==Histology==
  
−
[[Image:Reticulum Histology Sheep.jpg|thumb|right|250px|Reticulum Histology (Sheep) - Copyright RVC 2008]]
+
[[Image:Reticulum Histology Sheep.jpg|thumb|right|150px|Reticulum Histology (Sheep) - Copyright RVC 2008]]
−
The reticulum is lined by a '''keratinised stratified squamous epithelium''' and there are no glands present. The characteristic honeycomb appearance is formed by the mucosal layer trown into short and tall folds. The folds gradually merge into '''papillae''', where the reticulum meets the rumen. [[Tongue - Anatomy & Physiology#Types of Papillae|Conical papillae]], also called secondary papillae, are present on folds, providing a rough surface to increase food breakdown.
+
*Keratinised stratified squamous epithelium
 +
 
 +
*No glands
 +
 
 +
*Honeycomb appearance of short and tall folds
 +
 
 +
*Mucosal layer thrown into folds
 +
 
 +
*The folds gradually merge into papillae where the reticulum meets the rumen
 +
 
 +
*Lamina muscularis present as discrete bands of smooth muscle (not continuous)
  
 +
*[[Oral Cavity - Tongue - Anatomy & Physiology#Types of Papillae|Conical papillae]], also called secondary papillae, on folds providing a rough surface to increase food breakdown
 +
 +
*2 thick layers of tunica muscularis- inner circular and outer longitudinal
 +
 +
*The upper keratinised layer protects against abrasion
 +
 +
*The deeper layers metabolise [[Volatile Fatty Acids - Anatomy & Physioogy|volatile fatty acids]]
  
−
The '''lamina muscularis''' is present as discrete bands of smooth muscle (not continuous). There are two thick layers of '''tunica muscularis''', the inner circular and the outer longitudinal. The upper keratinised layer of the reticulum protects against abrasion and the deeper layers metabolise [[Volatile Fatty Acids|volatile fatty acids]].
 
  
 
==Species Differences==
 
==Species Differences==
  
 
===Small Ruminants===
 
===Small Ruminants===
 +
*Larger reticulum compared to cattle
 +
 +
*In sheep and goats the ridges of the reticular cells are lower and have more prominant serrated edges than in cattle
  
−
Small ruminants have a larger reticulum compared to cattle. In sheep and goats, the ridges of the reticular cells are lower and have more prominent serrated edges than in cattle. The papillated ruminal mucosa expands over a greater proportion of the reticulum.
+
*The papillated ruminal mucosa expands over a greater proportion of the reticulum
−
<br />
 
−
<br />
 
  
 
==Links==
 
==Links==
  
−
'''Click here for information on [[Rumen - Anatomy & Physiology|Rumen]]'''
+
[[The Rumen - Anatomy & Physiology|The Rumen - Anatomy & Physiology]]
 +
 
 +
[[The Omasum - Anatomy & Physiology|The Omasum - Anatomy & Physiology]]
 +
 
 +
[[The Abomasum|The Abomasum- Anatomy & Physiology]]
 +
 
 +
[[The Stomachs of the Ruminant - Anatomy & Physiology - Flashcards#The Reticulum|The Reticulum Flashcards]]
 +
 
 +
'''Video'''
  
−
'''Click here for information on [[Omasum - Anatomy & Physiology|Omasum]]'''
+
[http://stream2.rvc.ac.uk/Anatomy/bovine/Pot0052.mp4 Pot 52 Lateral view of the Abdomen of a young Ruminant]  
  
−
'''Click here for information on [[Abomasum - Anatomy & Physiology|Abomasum]]'''
+
[http://stream2.rvc.ac.uk/Anatomy/bovine/pot0175.mp4 Pot 175 Sections of the Ruminant Stomach]
  
−
{{Template:Learning
+
[http://stream2.rvc.ac.uk/Frean/sheep/LeftSideTopography.mp4 Left sided topography of the Ovine Abdomen and Thorax]
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|flashcards = [[Reticulum Flashcards]]
 
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<!-----|videos = [[Video: Sections of the interior of the complex ruminant stomach potcast|Sections of the interior of the complex ruminant stomach potcast]]<br>[[Video: Ruminant forestomach structure dissection|Ruminant forestomach structure dissection]]<br>[[Video: Bovine reticular groove potcast|Bovine reticular groove potcast]]<br>[[Video: Ruminant abdomen potcast|Ruminant abdomen potcast]]<br>[[Video: Ovine left-sided abdominal and thoracic dissection|Ovine left-sided abdominal and thoracic dissection]]<br>[[Video: Ovine right-sided abdominal and thoracic dissection| Ovine right-sided abdominal and thoracic dissection]]--->}}
 
  
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==Webinars==
+
[http://stream2.rvc.ac.uk/Frean/sheep/RightSideTopography.mp4 Right sided topography of the Ovine Abdomen]
−
<rss max="10" highlight="none">https://www.thewebinarvet.com/gastroenterology-and-nutrition/webinars/feed</rss>
 
−
<rss max="10" highlight="none">https://www.thewebinarvet.com/surgery/webinars/feed</rss>
 
  
−
[[Category:Stomach - Anatomy & Physiology]]
+
[http://stream2.rvc.ac.uk/Frean/sheep/RuminantStomachStructure.mp4 Structure of the ruminant forestomachs]
−
[[Category:A&P Done]]
 
−
[[Category:Alimentary Anatomy - Cattle]]
 

Revision as of 23:25, 25 August 2008

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()Map ALIMENTARY SYSTEM (Map)



Introduction

The reticulum is the second chamber of the ruminant stomach. It has regular contractions which precede the biphasic ruminal contraction for digestion of food particles.

Mechanical digestion and microbial fermentation occur to breakdown food particles for absorption. Volatile fatty acids are the major product of ruminant digestion.


Structure

Reticulum Anatomy (Sheep) - Copyright RVC 2008
  • Covered by greater omentum
  • The rumino-reticular fold often gets object lodged. When the rumen contracts, the object can be pushed through the reticulum wall into the pericardium and heart.
  • Opening at the cardia into both the reticulum and the rumen is called the reticuluar groove (see oseophageal groove). The reticular groove also opens into the omasum.
  • Ribs 6-8
  • From cardia to the diaphragm
  • Lies above the xiphoid process of the sternum
  • Serosa covers the surface

Function

  • Waste removal
  • Movement
  • Simpler products of digestion are assilimated directly, others continue down the digestive tract for further digestion


Ruminoreticular contraction

Diagram of the contractions of the ruminoreticulum - Copyright RVC 2008
  • Primary mixes food
    • Mixing cycle of ruminoreticulum
    • 2 contractions of the reticulum (2nd most powerful) which continues over the rumen
    • Ingesta flows from the reticulum to cranial ruminal sac to reticulum (or ventral sac)
    • Every 60 seconds
  • Secondary lets gas out
    • See eructation
    • Ingesta flows from ventral blind sac to dorsal blind sac to dorsal sac (eructation) to ventral sac

Vasculature

  • Cranial mesenteric artery
  • Celiac artery
  • Right and left ruminal arteries


Innervation

  • Dorsal vagus (CN X) (most important)
  • Ventral vagus (CN X)

Lymphatics

  • Numerous small lymph nodes are scattered in the grooves
  • The lymph drains to larger atrial nodes between the cardia and omasum, then to the cistera chyli


Histology

Reticulum Histology (Sheep) - Copyright RVC 2008
  • Keratinised stratified squamous epithelium
  • No glands
  • Honeycomb appearance of short and tall folds
  • Mucosal layer thrown into folds
  • The folds gradually merge into papillae where the reticulum meets the rumen
  • Lamina muscularis present as discrete bands of smooth muscle (not continuous)
  • Conical papillae, also called secondary papillae, on folds providing a rough surface to increase food breakdown
  • 2 thick layers of tunica muscularis- inner circular and outer longitudinal
  • The upper keratinised layer protects against abrasion


Species Differences

Small Ruminants

  • Larger reticulum compared to cattle
  • In sheep and goats the ridges of the reticular cells are lower and have more prominant serrated edges than in cattle
  • The papillated ruminal mucosa expands over a greater proportion of the reticulum

Links

The Rumen - Anatomy & Physiology

The Omasum - Anatomy & Physiology

The Abomasum- Anatomy & Physiology

The Reticulum Flashcards

Video

Pot 52 Lateral view of the Abdomen of a young Ruminant

Pot 175 Sections of the Ruminant Stomach

Left sided topography of the Ovine Abdomen and Thorax

Right sided topography of the Ovine Abdomen

Structure of the ruminant forestomachs

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