Equine Gastrointestinal tract

Question 1

Why cant a horse regurgitate or vomit?

Answer 1

the lower esophageal (cardiac) sphincter is extremely tight

Question 2

What is the margo plicatus?

Answer 2

Line in the equine stomach that marks the division of the glandular mucosa and non-glandular mucosa

Question 3

What are the bands of the large intestine called? what are the pouches called?

Answer 3

Bands: taenia
Pouches: haustra

Question 4

What part of the colon is more mobile? Why?

Answer 4

Left part is more mobile because the right ascending colon is more fixated by ligaments or plicae

Question 5

What are the bands of the large intestine?

Answer 5

local thickenings of the longitudinal stratum of the tunica muscularis and elastic fibers
- can be hidden (covered by connecting peritoneum) or free (not covered)

Question 6

How many bands does the ventral colon, pelvic flexure, left dorsal colon, dorsal diaphragmatic flexure, right dorsal colon, transverse colon, and descending colon have?

Answer 6

ventral colon - 4
pelvic flexure - 1
left dorsal colon - 1
dorsal diaphragmatic flexure - 1-3
right dorsal colon - 3
transverse colon - 2
descending colon - 2

Question 7

What are the names of the four bands of the colon?

Answer 7

dorsal, ventral, lateral, medial

Question 8

What is another name for the dorsal fold?

Answer 8

iliocecal fold

Question 9

What is another name for the lateral fold?

Answer 9

cecocolic fold

Question 10

What viscera can you feel by palpating the left wall of the abdomen?

Answer 10

• liver
• stomach
• spleen
• descending duodenum
• jejunum
• left dorsal colon
• left ventral colon

Question 11

What viscera are located between the left costal arch and tuber coxae?

Answer 11

• left dorsal quadrant: jejunum and descending (small) colon

- Left ventral quadrant: left ventral and left dorsal ascending (large) colon

Question 12

What viscera can you feel by palpating the right abdominal wall?

Answer 12

• liver
• right kidney
• descending duodenum
• cecum
• right ventral colon
• right dorsal colon

Question 13

Where is the apex of the cecum?

Answer 13

blind, ventral; terminates near the xiphoid cartilage

Question 14

True or false? The small intestine has bands (taenia)

Answer 14

False, only the large intestine does

Question 15

What can you use to find/identify the ascending duodenum and descending colon?

Answer 15

duodenocolic fold

Question 16

What can you use to identify/find the ileum and cecum?

Answer 16

ileocecal fold

Question 17

What can you use to identify/find the cecum and right ventral colon?

Answer 17

cecocolic fold

Question 18

Where can you find the caudal duodenal flexure?

Answer 18

Caudal to the root of the mesentery

Question 19

Where can you find the transverse colon?

Answer 19

cranial to the root of the mesentery

Question 20

What is the majority of the small intestine supplies by? (vessel)

Answer 20

cranial mesenteric artery

Question 21

What is the duodenum supplies by?

Answer 21

• cranial pancreaticoduodenal a. (of gastroduodenal a. of hepatic a. of celiac a.)
• Caudal pancreaticoduodenal a. (of cranial mesenteric a.)

Question 22

What is the jejunum supplied by?

Answer 22

jejunal aa. of cranial mesenteric a.

Question 23

What is the ileum supplied by?

Answer 23

• ileal aa. (last jejunal a. of cranial mesenteric a.)
• Mesenteric ileal branch of ileocolic a.
• (!!!)Antimesenteric ileal branch of ileocolic a. (absent in horse!!!!!)

Question 24

What is the majority of the large intestine supplied by?

Answer 24

branches of the cranial mesenteric a.

Question 25

What supplies the cecum?

Answer 25

- cecal a. of ileocolic a. | - lateral and medial cecal aa. of ileocolic a. (horse only)

Question 26

What supplies the ascending colon?

Answer 26

- colic branch of ileocolic a. | - Right colic a.

Question 27

What supplies the transverse colon?

Answer 27

middle colic a.

Question 28

What supplies the descending colon?

Answer 28

left colic a. ( anastomoses between left colic branch of caudal mesenteric a. and middle colic branch of cranial mesenteric a.

Question 29

What supplies the rectum?

Answer 29

- cranial rectal a. of caudal mesenteric a.

Question 30

What happens during splenic entrapment?

Answer 30

the dorsal and ventral colon moves between the spleen and the abdominal wall and slides into the space between the kidney, spleen, and nephrosplenic ligament

Question 31

How does a vet obtain access to thebase of the cecum in the horse?

Answer 31

through the right paralumbar fossa