Reticulum - Anatomy & Physiology

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