6. GIT tract - ruminants Flashcards
what is the tracheal bifurcation?
the division of the trachea into the right and left main bronchi
what is the Oesophageal hiatus?
the opening in the diaphragm through which the oesophagus passes from the thoracic to abdominal cavity
what is the course of the oesophagus in the cervical region
- Begins at the pharynx
- Descends dorsal to trachea to the middle of the neck
- Midneck the oesophagus lies on the left dorsolateral aspect of the trachea
- Regaining a median position above the trachea before or shortly after entering the thorax
what is the course of the oesophagus in the thoracic region
- continuing beyond tracheal bifurcation, it Passes over the heart before penetrating the oesophageal hiatus of the diaphragm
- Capable of reversed peristalsis or antiperistalsis. This allows food to be easily regurgitated from the rumen and chewed properly
what are the primary locations for choke in ruminants?
- thoracic inlet
- hiatus of diaphragm
- cardia of the rumen
what type of stomach do ruminants have?
complex and composite
name the 4 compartments of the ruminant stomach
- rumen
- reticulum
- omasum
- abomasum
what compartments of the stomach are in the fore stomach (proventriculi)?
rumen, reticulum, omasum
describe the internal structure of the fore-stomach
- Non-glandular
- Lined with stratified squamous epithelium
- Process and digest feedstuff
- Papillae
is the abomasum glandular or non-glandular
glandular
what is the main function of the rumen?
fermentation
what are grooves?
thickened smooth muscle pillars on the inside of the rumen - formed my tunica mucosa
what do the coronary pillars do?
divide the caudal blind sacs
what do Cranial pillars do?
divides the dorsal and cranial sacs
what is the rumen divided into?
sacs
describe the rumen structure
- Grooves - thickened smooth muscle pillars inside the rumen
- Ruminal pillars: divide the dorsal and ventral ruminal sacs (Longitudinal groove/pillar)
- Coronary pillars: divide the caudal blind sacs
- Cranial pillar: divides the dorsal and cranial sacs
describe the papillae structure and function in the forestomach
- mucosal projections like pegs
- Increase surface area
- Absorption of VFA’s (volitile fatty acids)
the rumen and reticulum occupy which side of the abdominal cavity?
left
describe the location of the reticulum
- caudal to diaphragm, closely situated to the heart and liver
- medial to the 6th to 8th ribs on the left side with the cranial wall at the elbow
microanatomy of the rumen of the cow
- No muscularis mucosa
- Complete short papillae and part of long papillae
- Stratified squamous epithelium
microanatomy of the reticulum of the cow
Sides and crests of long folds have conical papillae with keratinised tips
- Lamina propria
- lamina muscularis
- tunica muscularis
what does the reticulum do?
serves as a pump that causes liquid to flow into and out of the rumen
microanatomy of the rumen of the cow
- Complete short papillae and part of long papillae
- There is no muscularis mucosa in this part of the stomach
- Stratified squamous epithelium
describe the location of the omasum
Lies in the lower part of the cranial abdomen between reticulum and cranial rumen to the left and the liver on the right