Gastric functions.pptx. .

Pathophysiology. .

1. (GI TRACT )

2. Gastric functions and of the different cells that make up the stomach, pancreas, liver and gall bladder.

3. GASTRIC JUICE FUNCTIONS(cont..) Digestive functions: Mainly on proteins e.g.. |Gastric lipase| |Pepsin.| Action on the other gastric juice enzymes. Curding effect. GP 02

4. GASTRIC JUICE FUNCTIONS(cont..) Hemopoietic function. i . Intrinsic factor of Castle , secreted by parietal cells of gastric glands plays an important role in erythropoiesis. It is necessary for the absorption of vitamin B12 (which is called extrinsic factor) from GI tract into the blood. Vitamin B12 is an important maturation factor during erythropoiesis. Absence of intrinsic factor in gastric juice causes deficiency of vitamin B12, leading to pernicious anemia GP 02

5. GASTRIC JUICE FUNCTIONS (cont..) 3. Protective function (mucus). Protects the stomach wall from irritation or mechanical injury, by virtue of its high viscosity. ii . Prevents the digestive action of pepsin on the wall of the stomach, particularly gastric mucosa. Protects the gastric mucosa from hydrochloric acid of gastric juice because of its alkaline nature and its acid ­ combining power. GP 02

6. GASTRIC JUICE FUNCTIONS 4. Function of the HCL. Hydrochloric acid is present in the gastric juice: i . Activates pepsinogen into pepsin. ii. Kills some of the bacteria entering the stomach along with food substances. This action is called bacteriolytic action. iii. Provides acid medium, which is necessary for the action of hormones. GP 02

7. FUNCTIONS OF THE CELLS IN THE STOMACH GP 02 Cell Type Secretory product 1. Chef cells |Pepsinogen| |Lipase| |Renin| | Urase | |Gelatinase| 2. Mucous neck cells |Mucin in an acidic fluid| 3. G cells |Gastrin| 4. Parietal cells |HCL| |Intrinsic factor of castle| 5. EC and ECL cells |Serotonin| |Histamine|

8. FUNCTIONS OF THE CELLS IN THE LIVER AND GALLBLADDER GP 02 Cell type Secretory product 1. Hepatocytes(HC3) |Bile| |collagen| |cytokines.| 2. Hepatic Stellate cells (HSCs) |Cytokines| |growth factor.| 3. Kupffer cells |Vasoactive toxic mediators|

9. FUNCTIONS OF THE CELLS IN THE PANCREAS GP 02 NB: The function of the exocrine pancreas is to produce pancreatic juice containing enzymes that digest carbohydrates, proteins and fat. Cell type Secretory product Alpha cells |Glucagon| Beta Cells |Insulin| Delta cells | Somatostain |

10. GP 02 Thank you for listening!! See you in the exams.