5.1.2 Excretion Flashcards
What is the function of the hepatic portal vein?
Brings blood containing products of digestion into the liver from the intestines
What is the function of the hepatic artery?
Brings oxygenated blood to the liver from the heart
(is a narrow vessel as pressures are lower since blood travelled a long distance)
What is the function of the hepatic vein?
Carries deoxygenated blood away from the liver to the heart
What is the function of Kupffer cells?
Macrophages which digest foreign material and have a role in the immune system
What is the bile canaliculus?
Hepatocytes secrete bile here and from there it is drained into gall bladder to be stored
What is the importance of sinusoids?
Allows blood from the hepatic artery and hepatic portal vein to mix and exchange substances
What organelles do hepatocytes have and why?
- Nucleus: allows cell to divide
- Golgi apparatus
- Lots of mitochondria: provides ATP as cell is metabolically active
What are the three functions of the liver?
- Homeostatic control of blood glucose
- Deamination of excess amino acids
- Detoxification
What is happens to the amino acid in deamination?
- Amino group enters Ornithine cycle as ammonia
- Rest of molecule used in respiration or converted into lipids for storage
How is urea formed in the ornithine cycle?
Reaction between ammonia and carbon dioxide
What is ethanol broken down into, and what is the use of this product?
- Ethanol -> ethanal -> ethanoate
- Ethanoate is use din respiration or lipid synthesis
What enzyme breaks down alcohol?
Alcohol dehydrogenase
What enzyme breaks down hydrogen peroxide?
Catalase
