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Sunday, November 6, 2011

Homeostasis ll

1.   The pancreas
- functions as exocrine + endocrine gland.
- has 2 groups of cell in the pancreas.
- α & β-cells in the islet of Langerhans play (major role in blood glucose concdntration).
- α-cells - secrete glucagons
- β-cells - secrete insulin into blood capillaries.

α & β-cells in the islet of Langerhans










2.   Blood glucose level rises↑à due to carbohydrate breakdown.
3.   Insulin + glucagons have opposite effects.
4.   Insulin:
-  secreted by β-cells (when glucose level increases).
-  target organs = liver + muscle tissues.
-  convert glucose à to glycogen.
5.   Glucagon:
-  secreted by α-cells (when the glucose level decreases)
-  Target organ = liver cells.
-  convert glycogen à glucose.

Pancreas response to different level of glucose




















6.   Ingestion of glucose à increase insulin level ↑.
7.   2 types of diabetes: Type I & Type II.
Blood glucose & insulin level in normal & diabetic person.













8.   Formation of tissues fluid is a physical process.
9.   At arteriol end:  
-  smaller blood plasma content is forced out
-  when hydrostatic pressure (HP) > osmotic pressure (OP).
10. At venous end:
-  tissue fluid re-enters capillary
-  when osmotic pressure (OP) > hydrostatic pressure (HP).

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