Final Exam GI Physiology: Equine Digestion Flashcards Preview

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Flashcards in Final Exam GI Physiology: Equine Digestion Deck (24):
1

What is the most prominent feature of Equine digestion?

Fermentation in the Cecum and Large Colon

2

What is "Back" Fermentation?

Fermentation that occurs in the cecum and large colon, typical of equine animals

3

What are the fermentation products of equine digestion?

Acetate, Propionate, and Butyrate

4

VFAs provide what % of a horse's daily energy requirement?

Up to 75%

5

VFAs provide what % of a horse's daily energy requirement? What about a cow?

Horse: 75% DER through VFAs

Cow: 70% DER through VFAs

6

What is the origin of water found at the site of fermentation?

The cecum and colon is the origin of the water

7

Microbes hydrolyze cellulose into ______ .

Monomers

8

Cecal and Colonic lumen osmolality is dramatically increased by the hydrolysis reaction of what?

Cellulose into Monomers

9

What are produced monomers converted into?

Monomers are converted into 2-3 VFAs

10

What is the overall effect of increasing osmolality in the cecal and colonic lumen?

To draw large volumes of water from mucosal cells and basolateral interstitium (so pretty much getting it from plasma) and put the water into the lumen of the cecum and colon.

11

What % of body weight is extracellular water?

20%

12

How many times per day is the entire plasma volume secreted and absorbed across cecal and colonic mucosa in a horse?

5 TIMES PER DAY!

13

The movement of such large volumes of water across cecal and colonic mucosa causes increases in what 2 plasma components?

Renin and Aldosterone

14

Which is more acidic? The equine hindgut or the rumen?

The rumen is more acidic

15

In which species is microbial protein utilized? Why?

The cow.

There are no Na+peptide or Na+amino acid symports past the small intestine in the horse.

16

What are prominent features of the large intestine in regards to equine colon motility?

Mass Movement
Segmentation
Peristalsis
Antiperistalsis

17

Where is segmentation most prominent?

In the Cecum

18

Mass movements propel cecal contents from the ileum, into where?

Right Ventral Colon receives cecal contents via mass movements

19

Peristalsis propels cecal contents where?

Along the right and left ventral colons

20

What feature of the large intestine promotes retention of ingesta in the ventral colon?

Antiperistalsis at the pelvic flexure

21

The ventral colon is a major site of ______ absorption.

VFA

22

PSNS Neurotransmitters are important in coordinating what activities?

Peristalsis and antiperistalsis at the pelvic flexure

23

Where does impaction occur most frequently in a horse?

The pelvic flexure!

24

What effect does SNS innervation and opioids have on equine motility?

Inhibition of motility