WELCOME..... TO .....HIGH SCHOOL BIOLOGY BLOG !!!

Friday, July 6, 2012

LIVER I


















1.      Liver - made up of thousands of lobules.













2.      Each lobule - consists of rows of liver cells (hepatocytes).
3.      Sinusoids:
      - channels where blood flows
      - from the hepatic artery
      - into the hepatic vein.
4.      Hepatic vein:
      - carries deoxygenated blood + nutrients
      - to the heart.
5.      Hepatic portal vein:
      - carries blood-containing nutrients
      - from intestine
      - into lobules.
6.      Canalicluli:
      - where bile secreted by the liver cells flows
      - into bile duct.


















7.      Liver performs many important functions, all of which contribute to homeostasis:
      i.        Carbohydrate + protein metabolism
      ii.      site of synthesis of lipid (from excess glucose).
      iii.    detoxification - where drugs, toxins and poisons
             (taken in the diet/produced by bacteria)
             biochemically broken down + rendered harmless.
      iv.    production of bile + plasma proteins,
      v.      storage site of ions, minerals + vitamins
      vi.    generation of heat

8.      In the liver: glucose is oxidized à to CO2 + H2O.
9.      In the liver cells (stimulated by insulin)
      à excess glucose is converted to glycogen (glycogenesis),
10.  When the levels of blood glucose drop
      à glycogen is converted to glucose (presence of glycagon).
11.  When glycogen in the liver cells is depleted and glucose level fall
      à glucose is made from other non-carbohydrate sources = gluconeogenesis.

No comments:

Post a Comment