1/8/99

Physiology II

 

Chronic stress parasympathetic

caffeine increase acid release

red wine, increase acid release (histamine from skins)

synergy w/ acid production

most important enzyme carbonic anhydrase (stomach, pancreas, kidney, etc.)

 

Primary Secretory Activity of Stomach

Make HCl

water in lumen of gastric pit, combines w/ CO2 to form sodium bicarbonate (an acid) carbonic anhydrase increase 5000 fold, NaCL in area combines w/ H+ to form the HCl

 

histamine, gastrin, stomach distention, nerve input all activate this system

 

recommends drawing systems to understand (bid alimentary canal)

 

Vagus activates G cell, gastrin to Acinar cells of pancreas to release enzymes

 

all secretory products affect the pancreas along w/ the stomach

 

secretin is a hormone

 

Duodenum

pancreas-endocrine and exocrine organ

endo-insuline, etc.

exo-

2 types of cell

1.  Acinar-produce enzymes-regular cellular synthesis-proteolytic enzymes are inactive in pancreas and not activated until enter small intestine

     a.  Trypsinogen--pivital enzyme--activates the other 2

     b.  Chymotrypsinogen

     c.  Procarboxypeptidase

trypsin inhibitor-pancreatic molecule keeps trypsinogen in inactive form-- accumulation of enzyme in duct, inhibitor does not work

 

trypsinogen released, entrokinase activates trypsinogen to form trypsin (cleaves at certain aa bond)

trypsin activates Chymotrypsinogen to form Chymotrypsin

and Procarboxypeptidase to form Carboxypeptidase

all act together along w/ pepsin to digest protein

 

Lipases

-digest fat

Pancreatic amylases

DNAases

collengenases

2.  ductual-carbonic anhydrase-bicarbonate-to neutralize acid and float out everything-active range about pH =6.0

Digestive enzymes from small intestine

-entrokinase

-maltose cannot be absorbed,

-disacchridases, lactase, maltase, etc.