Pancreas Physiology (Costanza/Johnson)

Question 1

function of the aqueous component of pancreatic secretions

Answer 1

neutralize H+

**contains HCO3-

Question 2

function of the enzymatic component of pancreatic secretions

Answer 2

digestion

Question 3

cells that secrete the enzymatic portion of the pancreatic secretions

Answer 3

acinar cells

Question 4

cells that secrete the aqueous portion (bicarb) of the pancreatic secretions

Answer 4

centroacinar cells secrete it and ductal cells modify it

Question 5

stimulates pancreatic secretions?
inhibits pancreatic secretions ?
How does this compare the the salivary glands?

Answer 5

parasympathetic stim (Ach) and CCK
sympathetic inhib 

Opposite in the salivary

Question 6

pancreatic enzymes secreted in active form

Answer 6

amylase and lipases

Question 7

___ are secreted by the pancreas in there inactive form. Where are they converted into active enzymes?

Answer 7

proteases in duodenum

Question 8

describe how pancreatic enzymes are synthesized and secreted

Answer 8

made in RER of acinar cells → transferred to the golgi complex → condensed int vacuoles → conc into zymogen granules. They are stored here until stimulated for release (para or CCK)

Question 9

Pancreatic juice is (hypo, iso, hyper-tonic) solution

Answer 9

isotonic

Question 10

conc of what ions are the same as in plasma

Answer 10

Na and K

Question 11

What is the conc of HCO3- in pancreatic juices (compared to plasma)?

Answer 11

low flow: low HCO3

high flow: high HCO3

Question 12

What is the conc of Cl- in pancreatic juices (compared to plasma)?

Answer 12

low flow: high Cl

high flow: low Cl

Question 13

The apical membrane of ductal cells contains a _____ exchanger, and the basolateral membrane contains ______ exchanger

Answer 13

apical membrane contains a Cl/HCO3 exchanger,

basolateral membrane contains Na/K ATPase and an Na/H exchanger

Question 14

the venous blood of the pancreas is (acidic or basic) why?

Answer 14

acidic:
The net result the transport processes is net secretion of HCO3- into pancreatic ductal juice and net absorption of H+ into the blood

Question 15

rank the following ions in order of those that have the highest conc to least conc in pancreatic juices if there was a high flow rate? low flow rate?

Cl, Na, K, HCO3

Answer 15

high: Na > HCO3 > Cl > K
low: Na > Cl > HCO3 > K

Question 16

the aqueous and enzymatic componetns of pancreatic secretions are regulated (independently or with the same signals)

Answer 16

independently

Question 17

what stimulates the secretion of the aqueous component of pancreatic secretions?

Answer 17

H+ in the duodenum

*makes sense by bicarb is the aq part

Question 18

what stimulates the secretion of the enzymatic component of pancreatic secretions?

Answer 18

products of digestion

**makes sense bc this is the lipases, amylase, and proteases

Question 19

describe the phases of pancreatic secretions

Answer 19

cephalic: taste, smell, and conditioning → enzymatic secretion

gastric phase: distension of the stomach or vagus N → enzymatic secretion

intestinal:
CCK and para → enzymatic and
Secretin (released in resposne to H+ in duodenum) → aqueous secretion
**Ach and CCK potentiate effects of secretin

Question 20

describe the regulation of enzymatic secretion

Answer 20

phenylalanine, methionineView drug information, and tryptophan, small peptides, and FA stimulate I cells to make CCK → CCK binds CCKA receptor on ACINAR cells →IP3/Ca→ enzymes secreted

Question 21

describe the regulation of aqueous secretion

Answer 21

H+ inx in duodenum → S cells secrete secretin → binds receptor on DUCTAL cells → ↑cAMP → aqueous secretion