Equine Digestive Tract Anatomy: hindgut

Question 1

rate of passage factors

Answer 1

quantity and physical quality of food impacts speed

Question 2

why does discreet feeding have a bad impact on rate of passage?

Answer 2

it increases intake in a short period of time, so food passes through quickly and nutrients aren’t absorbed, leading to more fermentation

Question 3

the cecum has a homeostatic neutral pH

Answer 3

true

Question 4

what happens to the pH of the cecum if carbohydrate intake is increased?

Answer 4

more carbohydrates increase rate of passage and cause lots of carbohydrates to end up in the cecum where more acidic fermentation products are produced causing a lower acidic pH in the cecum

Question 5

where does the hindgut begin?

Answer 5

the ileocecal junction

Question 6

why is the ileocecal valve important?

Answer 6

it is a functional valve that causes feed to move one way and prevents backflow of digesta back into the ileum

Question 7

The large intestine is larger and more anatomically complex in horses

Answer 7

true

Question 8

hindgut components

Answer 8

cecum, large colon, small colon, and rectum

Question 9

hindgut volume

Answer 9

accounts for 61% volume of the intestinal tract

Question 10

hindgut rate of passage

Answer 10

slow, 35 hour average

Question 11

cecum also known as

Answer 11

blind sac

Question 12

cecum function

Answer 12

primary site for microbial fermentation, 35 liter capacity

Question 13

cecum characteristics

Answer 13

holds undigested feeds and contents enter and exit from the top

Question 14

cecum anatomy

Answer 14

large comma shaped organ, base occupies the right flank but extends forward

Question 15

cecum contractions

Answer 15

alternating contractions that mix and move digesta, haustra alternately contract and expand

Question 16

what are the haustra of the cecum?

Answer 16

small pouches caused by sacculation

Question 17

large colon also known as

Answer 17

ascending colon

Question 18

large colon size

Answer 18

diameter average 8-10” and 80 liter capacity

Question 19

large colon anatomy

Answer 19

folded together to form a double loop, left and right ventral and dorsal loops

Question 20

large colon function

Answer 20

efficiently mix digetsa through persaltic and antiperistaltic movement

Question 21

what is absorbed in the large intestine?

Answer 21

water, electrolytes, B vitamins and volatile fatty acids

Question 22

volatile fatty acids

Answer 22

contribute more than 60% of energy content needed, lipid soluble to move easily across membranes and be absorbed by the hindgut

Question 23

water

Answer 23

most water is absorbed in the foregut, but the hindgut provides a reservoir to pull water out of when dehydration occurs

Question 24

electrolytes

Answer 24

sodium and potassium are absorbed in the hindgut

Question 25

B vitamins

Answer 25

made from bacteria, water soluble to be absorbed in the hindgut

Question 26

large colon rate of passage

Answer 26

2-3 days

Question 27

large colon vulnerability

Answer 27

due to its anatomy, the large colon is vulnerable to twisting and gas buildup when nutrient flow is abnormal

Question 28

why is the large colon anatomy vulnerable?

Answer 28

the diameter of different segments changes abruptly and the large colon has several flexures

Question 29

small colon anatomy

Answer 29

consists of transverse and descending colon, contains pouches called sacculations that aid in forming fecal balls

Question 30

sacculations

Answer 30

form fecal balls by absorbing water and compacting feces

Question 31

rectum

Answer 31

terminal portion of the hindgut upon entering the pelvic inlet, opens to the exterior at the anus

Question 32

rectum innervation

Answer 32

sympathetic and voluntary nervous systems, has a voluntary sphincter