Intestinal and Colonic Absorption

Question 1

What is absorbed in the intestine?

Answer 1

solutes/water
monosaccharides
amino acids
lipids
vitamins
iron
calcium

Question 2

What is absorbed in the colon?

Answer 2

solutes/water
ammonia
SCFAs

Question 3

What is absorbed in the gallbladder?

Answer 3

solutes/water

Question 4

Name 4 characteristics of the jejunum

Answer 4

long absorptive villi
microvillar brush border
no Brunner’s glands
no Peyer’s patches

Question 5

Name 4 characteristics of the colon

Answer 5

columnar epithelium
goblet cells
long crypts
Paneth cells

Question 6

Name 4 characteristics of the gallbladder

Answer 6

mucosal folds
columnar epithelium
no muscularis mucosa
no submucosa

Question 7

What are the functions of the Na+ co-transporter?

Answer 7

transport glucose, galactose, amino acids, protons, vitamins

Question 8

How are glucose/galactose transported into and out of the cell?

Answer 8

transported in by SGLT1

transported out by GLUT1

Question 9

How are amino acids/peptides transported into and out of the cell?

Answer 9

transported in as dipeptides and tripeptides with H+

transported out as amino acids by specific transporters

Question 10

Explain lipid transport

Answer 10

products of lipid digestion solubilized in lumen in micelles

products of digestion released into cells, reesterified to original lipids

lipids packaged in chylomicrons

chylomicrons go to lymphatic capillaries by exocytosis

Question 11

Name the fat soluble vitamins and how they are absorbed in the intestine

Answer 11

Vitamins A, D, E, K

micelles form with bile salts

Question 12

Name the water soluble vitamins and how they are absorbed in the intestine

Answer 12

B complex, vitamin C, folate, nicotinate, pantothenate

Na+-coupled transporter

Question 13

How is Vitamin B12 absorbed in the intestine?

Answer 13

intrinsic factor-mediated

Question 14

Explain urea absorption in the colon

Answer 14

urea from urea cycle absorbed in colon
ureases and proteases break urea down to ammonia or ammonium
ammonia released back into portal circulation
ammonium released in waste

Question 15

Name some characteristics of the small intestines

Answer 15

villi
prominent brush border microvilli
sparse goblet cells
more than 20 endocrine cell types
rapid crypt to epithelial migration
absorption of amino acids, glucose, lipids, vitamins, and sodium

Question 16

Name some characteristics of the large intestines

Answer 16

sparse brush border microvilli
abundant goblet cells
3 endocrine cell types
slow crypt to epithelial migration
prominent SCFA production and absorption

Question 17

Name 2 types of medical therapy for malabsorptive disorders

Answer 17

re-hydration

anti-diarrheal agents

Question 18

Name the 4 types of anti-diarrheal drugs

Answer 18

prostaglandin synthetase inhibitors
opioid agonists
serotonergic antagonists
adrenergic agonists