Equine and Ruminant Foregut

Question 1

what is responsible for a horses inability to vomit

Answer 1

angle of esophagus

Question 2

what does the non-glandular region of the stomach in horses develop from?

Answer 2

esophagus

Question 3

what is the forestomach/proventriculus?

Answer 3

rumen + reticulum + omasum
non-glandular stomach

Question 4

what does the abomasum include?

Answer 4

cardiac, fundic, and pyloric gland regions of the simple stomach

Question 5

what is the pathway through the stomach in ruminants?

Answer 5

esophagus –> rumen + reticulum –> omasum –> abomasum –> duodenum

Question 6

what are the transverse sections of the bovine trunk and what do they do?

Answer 6

rumen + reticulum

reduce tough ingesta by processes of microbial fermentation

Question 7

describe the microanatomy layers of the rumen and reticulum

Answer 7

1) stratified squamous epithelium
2) lamina propria
3) muscularis mucosa
4) submucosa
5) muscularis interna

mucosal lining is keratinized –> makes epithelial tissue tougher due to grinding of food requirement

Question 8

describe the omasum contractions as it receives ingesta from rumen + reticulum

Answer 8

1) squeezes ingesta from the omasal canal into the recesses between the lamina
2) a mass contraction –> squeezes fluid from the material within the recesses (process essential to the continuing movement of ingesta to the abomasum)

Question 9

where does the abomasum receive ingesta from the omasum?

Answer 9

omasoabomasal orifice

Question 10

describe the development of the stomach and how it causes omentum formation

Answer 10

1) dilation of developing stomach
2) as the greater curvature of the stomach develops, the dorsal mesogastrium is displaced to the left
3) dorsal folds back upon itself and becomes the greater omentum
—> tissue running from the ventral (lesser curvature of the stomach) is now called the lesser omentum

Question 11

what organs develop as diverticula off the duodenum

Answer 11

1st part of duodenum, liver, gall bladder, pancreas

Question 12

what does the 1st part of the duodenum receive?

Answer 12

bile and pancreatic juices

bile duct travels dorsally along it

Question 13

how does the 1st part of the duodenum receive bile?

Answer 13

from liver/gall bladder via common bile duct

Question 14

how does the 1st part of the duodenum receive pancreatic juices?

Answer 14

from pancreas via main and accessory pancreatic ducts

Question 15

where do the common bile ducts and main pancreatic duct meet and drain into the duodenum?

Answer 15

major duodenal papilla

Question 16

what releases gastrin and mucous?

Answer 16

pyloric glands

Question 17

what is gastrin?

Answer 17

peptide hormone that stimulates parietal cells and aids gastric motility

Question 18

describe the mucosa of duodenum

Answer 18

characterized by prominent villi and crypts of intestinal glands

Question 19

what are brunner’s glands?

Answer 19

secrete an alkaline mucous that lowers acidity in the 1st part of the duodenum

Question 20

what do brunner’s glands do in the proximal duodenum?

Answer 20

secrete mucous to raise pH for pancreatic enzyme function and protect from stomach acids