Chapter 92: Small Intestine

Question 1

What is in the root of the mesentery?

Answer 1

1. Cranial mesenteric artery - divides into 12-15 branches-> arcades -> intestines-> cranial mesenteric vein-> portal system
2. Intestinal lymphatics
3. Mesenteric plexus of nerves (vagus + splanchnic)

Question 2

What makes up the duodenocolic ligament/fold?

Answer 2

The two peritoneal layers of mesoduodenum.

Question 3

How many times do the villi increase the surface area in the SI in dogs? Cats?

Answer 3

Dogs 8x
Cats 15x

Question 4

Villous epithelium in the SI turns over every how many days?

Answer 4

2-6 days

Question 5

What is the holding layer of the SI?

Answer 5

Submucosa

Question 6

The tight mucosal barriers in the SI require even water-soluble compounds to use transport pumps. These pumps need ATP to perform active/against gradient transport.

Where do they get their ATP?

Answer 6

The NA+K+/ATPase pump in the basement membrane.

It makes a sodium gradient that is essentially free energy for movement of other molecules against their gradients.

Question 7

With SI obstruction or ileus, do animals develop metabolic acidosis or alkalosis?

Answer 7

Acidosis due to increased secretion, dehydration etc.

Question 8

In proximal SI/Gastric obstructions, do animals develop acidosis of alkalosis?

Answer 8

Alkalosis from loss of HCl in vomiting.

Question 9

What should you consider adding to fluids in obstruction cases?

Answer 9

Potassium supplementation due to loss/decreased food.

Question 10

What type of antibiotics do you use for GI perioperative coverage?

Answer 10

1st generation cephalosporins

Question 11

What three sutures are recommended for closure of enterotomies?

Answer 11

Simple continuous, simple interrupted, gambee

Question 12

How do you do a leak test?

Answer 12

Either milk contents across and look for leakage or
Occlude ends and use needle + saline
~10cm segment + 16-19mL if hands and 12-15mL if doyens