chapter 20b gastro

Question 1

GI function is regulated to

Answer 1

maximize absorption, regardless of whether nutrients are need

Question 2

regulation of GI function is ___ based on concept of homeostasis

Answer 2

NOT

Question 3

reflexes mediated through the ____ control many GI functions

Answer 3

enteric nervous system

Question 4

___ is paired with enteric nervous system to control GI

Answer 4

ANS

Question 5

stimulates gastric secretion and motility, stimulates ileal motility and relaxes ileocecal sphincter, stimulates mass movement of colon

Answer 5

gastrin (stomach)

Question 6

inhibits gastric secretion and motility, potentiates actions of secretin on pancreatic bicarbonate secretion stimulates pancreatic enzyme secretion, stimulates bile secretion by liver, stimulates gallbladder contraction and relaxation of sphincter of Oddi

Answer 6

cholecystokinin CCK (duodenum and jejunum)

Question 7

inhibits gastric secretion and motility, stimulates pancreatic bicarbonate secretion potentiates actions of CCK on pancreatic enzyme secretion, stimulates bile secretion by liver

Answer 7

secretin (duodenum and jejunum)

Question 8

inhibits gastric secretion and motility, stimulates insulin secretion by pancreas

Answer 8

glucose-dependent insulinotropic peptide (duodenum and jejunum)

Question 9

what are the three phases of GI control

Answer 9

1. cephalic (head)
2. gastric (stomach)
3. intestinal (small intestine)

Question 10

hormone released from adipose cells when calories exceed demands, suppresses hunger and increases metabolism

Answer 10

leptin

Question 11

named after a related gene controlling hair color in rodents. powerful antagonist of MC3R and MC4R melanocortin receptors in the hypothalamus

Answer 11

agouti-related protein (AGRP) - obese people have elvated levels

Question 12

produced in hypothalamic neurons and other neurons of the sympathetic nervous system. stimulates appetite via several receptors

Answer 12

neuropeptide Y (NPY)

Question 13

neuropeptide precursor protein that is abundant in hypothalamus, unregulated after cocaine or amphetamine administration

Answer 13

cocaine and amphetamine regulated transcript (CART)

Question 14

reduce food intake when injected into the third cerebral ventricle

Answer 14

CART derived peptides

Question 15

precursor protein for melanocyte stimulating hormone (MSH), release of ___ product, beta-endorphin, is regulated by NPY

Answer 15

pro-opiomelanocortin (POMC)

Question 16

effective peptide that binds to receptors on neurons and other tissues. inhibits food intake and fat deposition

Answer 16

alpha-melanocyte stimulating hormone (alpha-MSH)

Question 17

what are two satiety factors

Answer 17

insulin and CCK

Question 18

what are two orexigenic factors (appetite stimulating)

Answer 18

ghrelin and resistin

Question 19

____ cells produce hydrochloric acid

Answer 19

parietal

Question 20

net result of acid production

Answer 20

1. H and Cl are secreted into the lumen of stomach

2. bicarbonate enters the interstitial fluid and then blood

Question 21

what three factors secrete acid

Answer 21

1. PNS
2. gastrin
3. histamine (paracrine)

Question 22

____ stimulates gastrin secretion

Answer 22

PNS

Question 23

increased acidity ___ gastrin release

Answer 23

inhibits

Question 24

effects of food entry into duodenum

Answer 24

+ = osmolarity, fat and acid, distention

Question 25

small volume of primary secretion contains water, electrolytes, and digestive enzymes

Answer 25

acinar cells

Question 26

large volume cells, bicarbonate rich secretion

Answer 26

duct cells

Question 27

hormones secreted by duodenum in response to the partially digested output from the stomach, which is called chyme

Answer 27

CCK cholecystokinin

Question 28

CCK stimulates ___ cells to secrete enzymes

Answer 28

acinar

Question 29

secretin stimulates ___ cells to secrete bicarbonate

Answer 29

duct

Question 30

stimuli for CCK release

Answer 30

fat and amino acids in duodenum

Question 31

stimuli for secretin release

Answer 31

acidity in duodenum

Question 32

stimulates bile secretion from liver

Answer 32

secretin

Question 33

stimulates gallbladder contraction and relaxation of sphincter of oddi

Answer 33

CCK

Question 34

name three incretins

Answer 34

1. glucagon like peptide - 1 2. oxyntomodulin (OXM) 3. glucose-dependent insulinotropic peptide (GIP)

Question 35

secreted from L cells of the ileum and colon, hormone/neurotransmitter has half life of only 1-2 minutes, has receptors in the brain. stimulates insulin secretion by beta-cells

Answer 35

glucagon like peptide - 1

Question 36

secreted from L cells, hormones appears to exert its effect through receptors for GLP - 1 as well as OXM specific receptors

Answer 36

oxyntomodulin (OXM)

Question 37

secreted from k cells, hormone inhibits gastric motility and stimulates insulin secretion

Answer 37

glucose-dependent insulinotropic peptide (GIP)

Question 38

important pair of neurotransmitters are derived from a common precursor together with their G-protein linked receptors OX1-R and OX2-R. arousal from sleep and food seeking behavior

Answer 38

orexins A and B (hypocretins)

Question 39

accounts for migrating motility complex, "housekeeping contractions", stimulates upper GI motility

Answer 39

motilin

Question 40

found in gastric/duodenal mucosa and pancreas, stimulated by acid, inhibited by Ach, inhibits the release of all gut hormones

Answer 40

somatostatin

Question 41

gastrin and Ach cause release from cells in stomach, stimulates acid secretion

Answer 41

histamine