exam 3 class 19

Question 1

Heme iron is absorbed by?

Answer 1

an apical transporter on the enterocyte

Question 2

ionized iron is actively absorbed by?

Answer 2

apical cotransport with on a protein called the divalent metal transporter 1
(DMT1)

Question 3

Inside the cell, enzymes convert heme
iron to and both pools of ionized iron
leave the cell on a transporter called?

Answer 3

ferroportin

Question 4

iron uptake by the body is regulated by a
peptide hormone called

Answer 4

hepcidin

Question 5

When body stores of iron are high, the
liver secretes ________, which binds to ________

Answer 5

hepcidin, ferroportin

Question 6

Hepcidin binding causes the

Answer 6

enterocyte
to destroy the ferroportin transporter,
which results in decreased iron uptake
across the intestine

Question 7

Most absorption of Ca2+ in the gut occurs by?

Answer 7

passive paracellular
pathways

Question 8

Calcium enters the enterocyte through apical channels and is actively transported across the basolateral membrane by either

Answer 8

(1) Ca2+ -ATPase
(2) Na+- Ca2+ antiporter

Question 9

Most water absorption takes place in?

Answer 9

small intestine

Question 10

Na+ and Cl- are absorbed via various transporters in __________ and cells of
colon

Answer 10

enterocytes

Question 11

Large intestine concentrates

Answer 11

waste

Question 12

chyme enters the large intestine through the ____________, continues to
be mixed by segmental contractions

Answer 12

ileocecal valve

Question 13

____ liters of unabsorbed chyme enters, most of this is absorbed and
_____liter of water is lost daily in feces

Answer 13

1.5
0.1

Question 14

Bacteria inhabiting colon break down undigested complex carbohydrates
and proteins through?

Answer 14

fermentation

Question 15

removes undigested feces from the body

Answer 15

The defecation reflex (spinal reflex)

Question 16

Stress may increase intestinal motility and cause?

Answer 16

psychosomatic diarrhea

Question 17

decrease motility in digestive system ?

Answer 17

constipation

Question 18

is a pathological state in which intestinal secretion of
fluid is not balanced by absorption, resulting in watery stools

Answer 18

Osmotic diarrhea

Question 19

occur when bacterial toxins enhance Cl- and fluid
secretion

Answer 19

Secretory diarrheas

Question 20

Food intake is based on
two hypothalamic
centers, behaviors and create sensations of
hunger and fullness.

Answer 20

-Feeding center
-Satiety center

Question 21

receives input
from different organs

Answer 21

Hypothalamus

Question 22

has both psychological
and physiological
components

Answer 22

Eating disorder
anorexia nervosa

Question 23

chemical signals secreted by adipose tissue

Answer 23

called adipocytokines (or adipokines

Question 24

leptin is an?

Answer 24

adipokine

Question 25

As fat stores increase, adipose cells secrete more
leptin, and?

Answer 25

food intake decreases (negative
feedback control)

Question 26

a brain neurotransmitter that seems to
be the stimulus for food intake

Answer 26

neuropeptide Y (NPY)

Question 27

Ingested food is used for

Answer 27

(1) Energy production, (2) Synthesis, and (3) Storage