Biology help - the Liver

Hi,

My class is doing a presentation on the digestive system with each of us being given a part. I have been given the liver. I do have some points but am struggling to find ones that are needed to be known by my class.

Does anyone know any key points that I need to put onto my presentation?

Thanks

The major function of the liver for digestion is the production of bile. Bile is a sort of a digestive fluid, which contains H20, inorganic ions and certain organic compounds. These are bile salts and bile pigments. Bile salts are actually derived from cholesterol, they include cholate and chenodeoxycholate (you may or may not need to know this). Bile pigments include bilirubin which is produced when hemoglobin inside RBCs is degraded.

The bile from the liver will go to a closely related organ, called the gall bladder. Here bile is made more concentrated (water is removed). The bile from both liver and gall bladder is sent via a bile duct to the small intestine.
In the small intestine, bile plays a role in emulsification of fats, making them easier to digest. It has some other functions too.
One last aspect is enterohepatic circulation. Basically from the small intestine, bile salts are not excreted in the urine but are reabsorbed in blood and taken back to the liver.
If you need details, ask away

Liver :
1. Detoxification
-by making insoluble drugs to be soluble thus able to be exreted out from your body
- alcohol metabolism

2. Digestion (bile formation)
- Haemoglobin breaks down in spleen into haem and globin. haem contains bilirubin which is toxic and has to be removed. bilirubin is converted to bile in liver. Bile then has a role to emulsify fat in small intestine as stated as thread above.

3. Deamination
- excess amino acid cannot be stored in body and has to be excreted out. Mammal on terrestrial environment choose to excrete amino acid by converting it to urea (bird as uric acid). amino acid loses the NH2 group and the NH2 group is enter the ornithine cycle for more info search the cycle.

4. Regulation and Assimilation
- This is the most well known role of liver and i regret putting it at last. Most nutrients from gastrointestinal tract/ SI are transferred via hepatic portal vein to liver. Liver acts as if the control room for these nutrients. E.g. excess glucose is converted to fat or glycogen. Excess fat is converted to glucose etc.