Hydrolytic Digestion

Question 1

Name the 2 sites of hydrolytic digestion

Answer 1

luminal digestion

brush border digestion

Question 2

What is digested in luminal digestion?

Answer 2

carbohydrates
proteins
lipids

Question 3

What is digested in brush border digestion?

Answer 3

maltose
peptides
monoglycerides

Question 4

Explain carbohydrate digestion

Answer 4

carbohydrates broken down to monosaccharides - starch, glycogen, sucrose, fructose, lactose, trehalose

Question 5

Name the 4 signs of carbohydrate malassimilation

Answer 5

fluid diarrhea
weight loss
borborygmus (gas noise in stomach)
flatulence

Question 6

Name some disorders of luminal maldigestion characterized by carbohydrate malassimilation

Answer 6

exocrine pancreatic insufficiency

small intestinal bacterial overgrowth

Question 7

Name some disorders of brush border maldigestion characterized by carbohydrate malassimilation

Answer 7

exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
small intestinal mucosal disease
disaccharidase defficiency

Question 8

Name some disorders of membrane malabsorption characterized by carbohydrate malassimilation

Answer 8

small intestinal mucosal disease (IBS)

Question 9

Explain protein digestion/absorption

Answer 9

stomach: proteins broken down to amino acids and oligopeptides by trypsin

small intestine: protein broken down to amino acids, oligopeptides, and tripeptides by enzymes (trypsin, elastase, etc.)

Question 10

Name the 2 signs of protein malassimilation

Answer 10

weight loss

+/- diarrhea

Question 11

Name some disorders of luminal maldigestion characterized by protein malassimilation

Answer 11

exocrine pancreatic insufficiency

small intestinal bacterial overgrowth

Question 12

Name some disorders of brush border maldigestion characterized by protein malassimilation

Answer 12

exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
food allergy/sensitivity reactions

Question 13

Name some disorders of membrane malabsorption characterized by protein malassimilation

Answer 13

intestinal lymphangiectasia
gastrointestinal neoplasia
gastrointestinal ulceration

Question 14

Explain lipid digestion/absorption

Answer 14

triglycerides are broken down into monoglycerides and fatty acids by lipases, hydrolases, and phopholipases

Question 15

Name the 3 signs of lipid malassimilation

Answer 15

steatorrhea
malodorous feces
weight loss

Question 16

Name some disorders of luminal maldigestion characterized by lipid malassimilation

Answer 16

exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
biliary obstruction
gastrinoma

Question 17

Name some disorders of brush border maldigestion characterized by lipid malassimilation

Answer 17

exocrine pancreatic insufficiency
small intestinal bacterial overgrowth
duodenitis
jejunitis
ileitis

Question 18

Name some disorders of membrane malabsorption characterized by lipid malassimilation

Answer 18

intestinal lymphangiectasia

biliary obstruction

Question 19

Name the 4 prerequisites for fermentative digestion

Answer 19

reservoir for retention of ingest and microbes
oxygen content must be low (anaerobic environment)
acidity; suitable pH range (6-7)
removal mechanism for end products

Question 20

Explain the anaerobic environment of fermentative digestion

Answer 20

colonic bacteria are strict anaerobes

oxygen introduced in food and water diffuses across foregut epithelium, used by facultative anaerobes

Question 21

What are the substrates and end products of fermentative digestion

Answer 21

carbohydrates - VFA + CO2 + CH4
proteins - ammonia + keto acids
lipids - fatt acids + propionate
microbial cells - anaerobes

Question 22

In cat and dog, what area of GI tract has the most fermentative capacity?

Answer 22

colon

Question 23

Explain succession ecology of the GI tract

Answer 23

there are increasingly more bacteria in the ileum and large intestines than anywhere else because there is more breakdown occurring in those areas