Pancreas lec .7 16 March 14
Physiological anatomy &functions
Head located within curvature of duodenum
Body and tail extends to the spleen.
functions
1.endocrine portion-- islets of Langerhans
Insulinby B CELLS and glucagon--- --blood
2.Exocrine portion of pancreas pancreatic juice---
.
Exocrine function of pancreas
Functional Anatomy
.Digestive enzymes by the pancreatic acinar
cells
bicarbonate by duct cells-------pancreatic duct-- .----join common bile duct (from liver and gallbladder)---sphincter of Oddi ---duodenum.
Composition of Pancreatic juice
1.pancreatic digestive enzymes
2. anions (HCO3-)
Cations (Na+, K+ , Ca+ , )
3. Large amounts of water
.
The two important components of pancreatic juice, are bicarbonate ions and water
functions of pH 8 :
a. which provides a favorable conditions for digestive enzymes
b.helps to neutralize the acidic chyme as it arrives from the stomach .
C.intestine blocks the action of pepsin which might damage the duodenal wall.
Digestive Enzymes
1Carbohydrates-- pancreatic amylase
2.fat enzymes --- pancreatic lipase cholesterlesterase;phospholipase
3.Proteolytic enzymes--trypsin , chymotrypsin , carboxypolypeptidase
Trypsin inhibitors--- Prevents digestion of the Pancreas Itself
Regulation of Pancreatic Secretion
1.hormonal
2.Neural---ACH
Hormonal---mostly
CCK----.
Secretin----.
Neural control
Acetylcholine----
Phases of Pancreatic Secretion
cephalic phase -----ACH—enzymatic stimulation2. Gastric phase -- Distension of stomach-----ACH3.Intestinal phase:acid --secretin—high HCO3+water
