Difference between revisions of "Reticulum - Anatomy & Physiology"

Revision as of 14:07, 6 September 2010

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.

Cranial to the rumen

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

See rumination

See eructation

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

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

Test yourself with the Stomachs of the Ruminant flashcards

Reticulum Flashcards

Links

The Rumen - Anatomy & Physiology

The Omasum - Anatomy & Physiology

The Abomasum- Anatomy & Physiology

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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-{{OpenPagesTop}}
 ==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==
-[[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 [[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 [[Rumen - Anatomy & Physiology|rumen]] is called the reticuluar groove (see [[Oesophageal Groove|oseophageal groove]]). The reticular groove also opens into the [[Omasum - Anatomy & Physiology|omasum]].
+*Cranial to 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==
-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==
-[[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 [[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
+==Vasculature==
-The contractions have two main functions:
+*Cranial mesenteric artery
-: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.
+*Celiac artery
-==Vasculature==
+*Right and left ruminal arteries
-The reticulum receives blood supply from the '''cranial mesenteric artery''', '''celiac artery''' and '''right and left ruminal arteries'''.
 ==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 ([[Cranial Nerves - Anatomy & Physiology|CN X]]) (most important)
+*Ventral vagus ([[Cranial Nerves - Anatomy & Physiology|CN X]])
 ==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
-==Histology==
-[[Image:Reticulum Histology Sheep.jpg|thumb|right|250px|Reticulum Histology (Sheep) - Copyright RVC 2008]]
+*The lymph drains to larger atrial nodes between the cardia and [[Omasum - Anatomy & Physiology|omasum]], then to the cistera chyli
-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.
-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]].
+==[[Reticulum - Histology|Histology]]==
 ==Species Differences==
 ===Small Ruminants===
+*Larger reticulum compared to 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.
+*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
 <br />
 <br />
+==Test yourself with the Stomachs of the Ruminant flashcards==
+[[The_Stomachs_of_the_Ruminant_-_Anatomy_%26_Physiology_-_Flashcards#The_Reticulum|Reticulum Flashcards]]
 ==Links==
-'''Click here for information on [[Rumen - Anatomy & Physiology|Rumen]]'''
+[[Rumen - Anatomy & Physiology|The Rumen - Anatomy & Physiology]]
+[[Omasum - Anatomy & Physiology|The Omasum - Anatomy & Physiology]]
+[[Abomasum - Anatomy & Physiology|The Abomasum- Anatomy & Physiology]]
+'''Video'''
+[http://stream2.rvc.ac.uk/Anatomy/bovine/Pot0052.mp4 Pot 52 Lateral view of the Abdomen of a young Ruminant]
+[http://stream2.rvc.ac.uk/Anatomy/bovine/pot0175.mp4 Pot 175 Sections of the Ruminant Stomach]
+[http://stream2.rvc.ac.uk/Frean/sheep/LeftSideTopography.mp4 Left sided topography of the Ovine Abdomen and Thorax]
-'''Click here for information on [[Omasum - Anatomy & Physiology|Omasum]]'''
+[http://stream2.rvc.ac.uk/Frean/sheep/RightSideTopography.mp4 Right sided topography of the Ovine Abdomen]
-'''Click here for information on [[Abomasum - Anatomy & Physiology|Abomasum]]'''
+[http://stream2.rvc.ac.uk/Frean/sheep/RuminantStomachStructure.mp4 Structure of the ruminant forestomachs]
-{{Template:Learning
-|flashcards = [[Reticulum Flashcards]]
-<!-----|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]]--->}}
-==Webinars==
-<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]]
-[[Category:A&P Done]]
-[[Category:Alimentary Anatomy - Cattle]]