Why are products of digestion useful in the liver?
They provide the starting point for many metabolic activities of the liver.
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What is the function of the hepatic vein?
Returns blood to the heart from the liver.
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What is the function of the hepatic portal vein?
Supplies the liver with products of digestion from the intestines.
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What is the function of the hepatic artery?
Supplies the liver with oxygenated blood.
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What is the biological name for liver cells?
Hepatocytes.
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State three key features of hepatocytes.
Prominent golgi apparatus, large nuclei, large numbers of mitochondria.
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What do large numbers of mitochondria, large nuclei and prominent golgi apparatus indicate about the function of hepatocytes?
That they are metabolically active cells.
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Where does blood from the hepatic artery and hepatic portal vein mix?
Spaces called sinusoids.
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What cells are sinusoids surrounded by?
Hepatocytes.
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Why does blood from the hepatic portal vein and the hepatic artery mix?
To increase the oxygen content of blood from the hepatic portal vein, so that hepatocytes have enough oxygen for their needs.
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What type of cells do sinusoids contain?
Kupffer cells.
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What is the function of Kupffer cells?
They ingest foreign particles and help to protect against disease.
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Where do hepatocytes secrete bile into?
Spaces called canaliculi.
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From canaliculi, where does bile travel?
To bile ductiles, which take it to the gall bladder.
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How is bile produced?
From the breakdown of blood in the liver.
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State three main function of the liver related to homeostasis.
Carbohydrate metabolism, deamination of excess amino acids & detoxification.
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How are hepatocytes involved in controlling high blood glucose concentrations?
They are stimulated by insulin to convert glucose into the storage carbohydrate glycogen when BG levels rise, and about 100g of glycogen is stored in the liver.
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How are hepatocytes involved in controlling low blood glucose concentrations?
When BG levels fall, hepatocytes convert glycogen back into glucose under the influence of glucagon.
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What is transamination?
The conversion of one type of amino acid into another.
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Why is transamination important?
The diet doesn't always contain the correct balance of amino acids, which can cause problems, but transamination means necessary amino acids can be converted from ones already present.
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What is deamination?
The removal of an amine group from a molecule.
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Why is deamination important?
The body cannot store protein or amino acid, so without deamination, amino acids and proteins would be wasted.
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What are the main steps of deamination?
Amino acid is deaminated, converted into ammonnia, then into urea.
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Through what process is ammonia converted into urea?
The ornithine cycle.
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What happens to the urea produced in the ornithine cycle?
Most urea is excreted by the kidneys, some is converted into lipids for storage or fed back into cellular respiration.
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Give an example of one detoxifying action the liver performs.
It converts ethanol into ethanal using the enzyme, alcohol dehydrogenase. Ethanal is then converted into ethanoate which can be used in cellular respiration or to build up fatty acids.
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Other cards in this set
Card 2
Front
Name the main three metabolic waste products in mammals.
Back
Carbon dioxide, bile pigments, nitrogenous waste products (urea).
Card 3
Front
What process is carbon dioxide a waste product of?
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