Pancreatic Function and Secreton Flashcards Preview

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Flashcards in Pancreatic Function and Secreton Deck (13)
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1
Q

Purpose of pancreas

A

Lubricaiton and protection of mucosa

Enzymatic hydrolases and catalyzes just about everything

Neutrilization of acidic contents in intestine coming from the stomach…maintain proper pH

2
Q

Exocrine and endocrine of the pancreaes

A

Exocrine set up with ductal cells (produce bicarbonate) and exocrine cells (produce enzymes)

Endocrine functions important in metablism

3
Q

Endocrine function cells

A
Insulin - beta cells
Glucagon - alpha cells
Somatostatin - delta cells 
Panc polypeptide
VIP 
Sometimes G cells...potential gastrinoma...in Zollinger-ellison, no feedback inhibition of acid secretion like there is for G cells of gastric mucosa
4
Q

Enzymatic secretions

A

FOrmed in acinar cells…major stimulus is CCK with a little vagus drive

CCK released by intestinal mucosal epithelial cells in response to fats….release increased by CCK-RP by enterocytes and by monitor peptide forom pancreas

All released by exocytosis

Some enzymes taken up by intestinal mucosa and reciruclated and some are digested

Acinar and duct structure similar to salivary glands

5
Q

Types of enzymatic secretions

A

Proteases…trypsinogen converted by enteropeptidase by trypsin…trypsin inhibitor to prevent autodigestion

Chymotrypsinogen
Procarboxypeptidase A and B

Panc amylase - starch to disacc

Lipases

Colipase - displace bile salt so lipases can act

Nucleases and proelastase

6
Q

Electrolyte secretions

A

From ductal cells

High in HCO3 and needs carbonic anhydrase and CO2 from circulation

Results in acid tide leaving the pancreas….goes ot liver to mix with stomach alkaline tide…normally no NET change in H and HCO3 in blood or GI tract

7
Q

Electrolyte secretory control

A

Separate control from enzymatic secretions

Primary is secretin…stimulated by presence of aicd in intestine

Weak stimulus by CCK and Ach

8
Q

Phases of regulation

A

Interdig - ongoign enzyme synthesis but little release

Ceph - vagal mediated release of enzymes (Ach)

Gastric - weak stimulation by gastrin and Ach

Intestinal - Secretin - major effect to dec acid and inc bicarb so stimulation of duct cells

CCK - inc enzyme syntehsis and release via acinar cells

9
Q

Secretin source stim, receptors, 2nd mess, trophic effect, effects

A

S cells of intestinal

Acid, AA

Membrane bound

cAMP

None

Electrolyte secretions wthrough ductal

10
Q

CCK stim, source, recept, 2nd mess, trophic, effects

A

I cells of intestinal mucosa

AA, FA, Ach, dec by trypsin

Membrane bound

IP3/Ca - cGMP

Inc pancreatic growth

Enzymatic secretions and acinar cells

11
Q

CCK secretion

A

BY the I cells…stimualted by release of CCK-RP from other duodenal mucosa cells

Monitor peptide release by pancreatic acinar cells when stimulated to…increase their enzyme synthesis…cephalic phase neural stim inc enzymes syntehsis and release MP into lumen and into duodenum where it stimulates CCK

12
Q

CCK effects

A

Gallbladder contraction

Pancreas acinar secretion

Stomach reduced emptying

Sphincter of oddi relaxation

ALL of this is working to digest and match delivery to digestive and absorptiive cpaacity

13
Q

Dysfunctions

A

Pancreatitis

Diabetes

Peptic ulcers - gastric vs Duodenal**

Loss of lipase - steatorrhea