What signals the secretion of Pancreatic Juice?

[ipodtouch]

---

Members don't see this ad.

I'm going through the Kaplan book and it indicates that
1.) Secretin signals Pancreatic Juice
2.) CCK causes release of Bile


But looking on Wiki, it says that CCK causes release of Pancreatic Juice.


I was wondering if both actually affected Pancreatic Juice, and what the correct answer on the MCAT would be...

 

[gravitywave]

its both

CCK signals the juice to start flowing
secretin signals cells lining the ducts to modify the electrolytes in the juice as it flows by

CCK & secretin will both be around once you've eaten, so they work together

 

[ipodtouch]

secretin signals cells lining the ducts to modify the electrolytes in the juice as it flows by

whoaaa haven't heard this before.
Could you be so kind to teach me?

 

[gravitywave]

whoaaa haven't heard this before.
Could you be so kind to teach me?

i've honestly already told you everything you'd need for an MCAT question 😛

but here's a few more details as i understand them: the juice starts in the base of a gland, this base is called an acinus. the cells that make up the acini in the exocrine pancreas respond to CCK by generating juice. the juice has Na+, Cl-, HCO3- and K+ in it, among other things. as the juice flows to the duodenum, the cells lining the ducts along the way are responding to secretin by modifying the ion concentrations in the juice as it flows by. they take Cl- out, and secrete HCO3- in its stead. this HCO3- ends up in the duodenum, where it helps neutralize stomach acid (H+).

 

[MedPR]

For the MCAT you should know that secretin is stimulated by the lowering of the pH in the small intestine (due to gastric juices leaking through with the food, while CCK is stimulated by the presence of fats. Both will stimulate pancreatic secretions.