Wk3 H20, Electrolyte, Intestinal Motility

Question 1

substance that promotes bowel loosening and movement

Answer 1

Purgative

Question 2

feeling of needing to pass stool even when bowel is empty

Answer 2

tenesmus

Question 3

Location of cells that absorb fluid:

Answer 3

tips of villi

Question 4

Location of cells that secrete fluid:

Answer 4

crypts

Question 5

How does sodium get in apical side for water to follow?

Answer 5

NHE

sodium hydrogen exchanger

Question 6

How does chloride get in apical side to join sodium and water follow?

Answer 6

Chloride/Bicarb exchanger

Question 7

Electrogenic uptake of water?

Answer 7

Na+ / Glucose (SGLT1-apical) (GLUT-2, basolateral)

**Cl- and H20 follow passively via tight junctions

Question 8

long reflex regulator of Cl- secretion:

Answer 8

Ach

VIP

Question 9

GI peptide in goblet and ECL cells

increases cGMP

promotes Cl- secretion via CFTR

Answer 9

Guanylin

Question 10

Drug that activate guanylate cyclase type C to treat constipation:

Answer 10

Linaclotide

Question 11

The bulk of fluid reabsorption is driven by?

Answer 11

Nutrient-coupled electrogenic sodium absorption

SGLT-1
Na/AA

Question 12

How does sodium enter COLONOcytes?

Answer 12

ENaCs

electrogenic

mostly in distal colon

Question 13

What stimulates ENaC expression in colonocytes?

Answer 13

Aldosterone

just like the kidney!

Question 14

How does electroneutral NaCl absorption occur n the colon?

Answer 14

NHE’s

Na+/H+

Question 15

Name some secretagogues (enhance secretion)

Answer 15

PNS–Ach

VIP/NO

Histamine

PG’s

gastrin

secretin

motilin

serotonin

LCFAs

bile salts

Bacterial toxins

Question 16

Name some absorbagogues (enhance absorption):

Answer 16

SNS

somatostatin

Aldosterone

SCFAs

opiods

Question 17

Diarrhea from excess secretion of CL-?

Answer 17

Secretory

Question 18

Diarrhea from poor absorption of nutrients?

Answer 18

Osmotic

Question 19

What regulates intestinal motility?

Answer 19

BER (basal electric rhythm) — cells of Cajal?

Enteric nervous system

Question 20

BER cycle rate in jejunum vs ilium?

Answer 20

jejunum – 12/min

distal ilium – 8/min

Question 21

See slide 31 and 35

Answer 21

for specific regulators of motility

Question 22

BER at ileocecal valve vs sigmoid colon:

Answer 22

IC valve – 2/min

SC – 6/min

Question 23

Excess production of what causes Inlammatory Bowel Disease sx?

Answer 23

NO

**caused by Crohn’s or ulcerative colitis

Question 24

Intestine becomes more sensitive and contract more frequently?

Answer 24

Irritable Bowel Syndrome