GI Tract, Species Comparison- Horses, Pigs and Rabbits Flashcards
What is the implication of horses having an oesophagus lumen that narrows at the thoracic inlet
this predisposes them to choking
What is the nerve supply of the oesophagus in horses?
The vagus nerve,
What is the epithelium structure of the oesophagus in horses
Stratified squamous and it is keratinised
Where do you enter after the oesophagus?
The stomach
What does ‘composite stomach mean’
Has both glandular and non-glandular regions
Margo plicatus
separates the glandular and non-glandular regions
Which side of the stomach is more rough
non-glandular side
Why Can’t horses vomit?
strong sphincters, allow gas in but not back out
What does the Fundic gland region contain?
gastric pits, columnar epithelium and surface mucous cells
Where are columnar epithelium usually found?
In areas of high acidity (stomach)
What is the role of the mesentry?
to keep the duodenum and small intestine in place
What is a potential problem for the mesentry?
can become twisted
How are the illeum and caecum connected?
illeum is terminated at the ileal papillae and then leads to the caecum
Caecum
made up of three parts, base, body and apex- it is where fermentation takes place
What are some adaptations of the Large intestine/
contains bands or Taeniae- longitudinal smooth muscle cords on the caecum and segments of the colon
Sacculation
found on the large intestine, increases surface area and prolongs retention time
What are the 3 parts of the small intestine?
Duodenum, ileum and the jejunum
Fundic gland region
tubes found in the fundus of the stomach, contain 2 or more tubes that open into a single duct
Duodenum
first part of the small intestine, very mobile and associated with the mesentry
What are the 3 parts of the coecum?
Base, Body and the Apex
What are the parts of the Large intestine?
Cecum, Colon and the rectum
How many bands does the coecum and ventral colon have?
4
How many bands does the right dorsal colon have?
3
What are the 3 parts of the colon?
Descending, Ascending and Transverse
What is the most modified part of the colon?
Descending
What are the parts of the Ascending colon?
RVC, sternal flexure, LVC, pelvic flexure, LDC, diaphragmatic flexure, RDC
Rugae
folds in the stomach lining
What is the function of the pyloric gland?
Secretes a mucus which coats the stomach and prevents it from destroying itself
Fundic gland
Produces most of the stomach acid
Pylorus
muscular valve that holds food in stomach
Saccus Cecus
begisn digestion/ releases enzymes- furthest part from the oesophagus
Nepro-splenic ligament
attaches the spleen and kidney together
Diverticulum
Colon in pigs
3D Shaped, coils around mesentry
What organs are found on the left hand side of the horse?
Most of the small intestine, and the stomach
What organs are found on the right hand side of the horse?
The caecum
What lines the colon in the pig?
Mucosal surface is relatively flat and not lined with villi
What is found on the left hand side of the pig?
The caecum (and the spleen is connected to the greater curvature of the stomach)
What kind of stomach do rabbits have?
Thin walled and simple, with well-developed sphincters so they cannot vomit
What adaptation makes rabbits agile?
They have a rapid digestion of food
sacculus rotundus
junction between the illeum, caecum and colon
Small intestine in rabbits
Shorter than in other animals, Pylorus and duodenum can be easily compressed
Ileolic valve
Controls movement of ingesta from the illeum into the sacculus
Caecum in rabbits
Most prominent organ, where all the fermentation occurs (full of lymphoid tissue)
Fusus coli (in pigs)
Acts as a pacemaker to control digestion
Cecotrophy
Reingesting nutrients from intestinal contents
Which part of the stomach does the oesophagus enter?
The cardia region
caecocolic orifice
sphincter between the caecum and the ascending colon
