5.3 Liver Flashcards
What are the 3 main metabolic waste products in animals?
Carbon dioxide
Bile pigments
Nitrogenous waste
What is CO2 a waste product of?
Respiration it is excreted from lungs
What are bile products a waste product of?
Haemoglobin breakdown they are excreted in bile from the small intestine via the gall bladder and bile duct
What is nitrogenous waste/urea a waste product of?
The breakdown of amino acids in the liver excreted by kidneys into the urine
How much of the total body mass does the liver make up?
5%
What can the liver do if damaged/ part removed?
Regenerate and grow quickly
The liver has a rich blood supply of what per minute?
1 dm3
Which artery supplies the liver with blood?
The hepatic artery
Which vein removes blood from the liver and returns it to the heart?
The hepatic vein
What does the hepatic portal vein do?
Carries blood containing digestive products from intestines to liver
Up to 75% of blood flowing through the liver comes from where?
The hepatic portal vein
What are liver cells called?
Hepatocytes
What organelles indicate hepatocytes are metabolically active?
Large nuclei
Prominent Golgi apparatus
Lots of mitochondria
Hepatocytes can divide and replicate so the liver can regenerate even if how much is lost?
65%
What are surrounded by hepatocytes?
The sinusoids
What are sinusoids?
Spaces where blood from hepatic artery and hepatic portal vein mix
The mixing of blood in the sinusoids can do what?
Increase the oxygen content of the blood supplying hepatocytes with enough oxygen for their needs
Sinusoids contain kuppfer cells what do they act as and how?
Macrophages
Ingesting foreign particles and helping protect against disease
What are the canaliculi?
Spaces where hepatocytes secrete bile from breakdown of blood
From the canaliculi bile drains into where?
Bile ductules which then take it to the gall bladder
(Carbohydrate metabolism) hepatocytes are involved in homeostatic control of what?
Glucose levels
(Carbohydrate metabolism) 1. Carbohydrates are broken down to what and where?
Glucose
In the small intestine
(Carbohydrate metabolism) 2. What happens to the glucose in the small intestine?
Absorbed in to the bloodstream
(Carbohydrate metabolism) 3. The glucose in the bloodstream is transported where?
To the liver
(Carbohydrate metabolism) 4. The liver does what to the glucose?
Removes excess and stores it as glycogen
(Carbohydrate metabolism) 5. What happens to glycogen between meals?
It is broken down between meals as a source of energy
(Carbohydrate metabolism) 6. The glycogen is converted to what and released where when blood sugar levels fall?
Glucose
Released into bloodstream
(Carbohydrate metabolism) 6. Which hormone causes glycogen to be converted to glucose?
Glucagon
(Deamination) hepatocytes carry out transamination, what is this?
Conversion of one amino acid to another
(Deamination) why is transamination important?
The diet doesn’t always have the correct balance of amino acids
(Deamination) deamination involves the removal of what?
An amine group from an amino acid
(Deamination) deamination is important as the body cannot do what?
Store proteins and amino acids they would be wasted and excreted if it weren’t for hepatocytes
(Deamination) the amine group is removed and converted to what?
Ammonia
(Deamination) the ammonia is then converted to what? In which cycle?
Urea
The ornithine cycle
(Deamination) which is more toxic ammonia or urea?
Ammonia
Urea is toxic in high concentrations
(Deamination) what happens to the remainder of the amino acid during deamination?
Used in cell respiration or converted into lipids
In the ornithine cycle ammonia is converted to less toxic urea in a series of what?
Enzyme controlled reactions
Look over diagram of ornithine cycle
Look over diagram of ornithine cycle
(Detoxification)Why are levels of toxins in the body always increasing?
Metabolic processes producing potentially toxic substances
Choice - alcohol and drug consumption
(Detoxification) where in the body are a lot of toxic substances detoxified and made harmless?
The liver
(Detoxification) what is one example of detoxification?
Breakdown of hydrogen peroxide
(Detoxification) in breakdown of hydrogen peroxide, what do hepatocytes contain?
Catalase
(Detoxification) in breakdown of hydrogen peroxide what does catalase do?
Breaks down hydrogen peroxide into oxygen and water
(Detoxification) what is another example of detoxification?
Break down of ethanol toxic drug in alcohol
(Detoxification) in ethanol breakdown, what enzyme is found in hepatocytes?
Alcohol dehydrogenase
(Detoxification) what does alcohol dehydrogenase do?
Breaks down ethanol to ethanal
(Detoxification) in ethanol breakdown, ethanal is converted to what? And where is this used?
Ethanoate
Used to build up fatty acids or used in respiration
alcohol produces a toxic enzyme called what?
acetaldehyde
acetaldehyde can damage the liver, what is its effects?
permanent scarring
reduced ability for liver to regenerate
irreversible
decreases life expectancy
cirrhosis of the liver is a disease when normal liver tissue is replaced by what?
fibrous scar tissue
what is the most common cause of cirrhosis?
excessive alcohol consumption
what are the 3 stages of alcoholic liver disease?
- alcoholic fatty liver disease
- alcoholic hepatitis
- liver cirrhosis
in alcoholic fatty liver disease what happens to the nuclei of hepatocytes and the liver?
displaced by fat filled vesicles
liver gets larger
in alcoholic hepatitis the patient has fatty liver, damaged hepatocytes - what else happens?
narrowing of the sinusoids and hepatic veins
in alcoholic cirrhosis liver tissue is irreversibly damages what happens to hepatocytes? and in turn the liver?
many die and are replaced with fibrous tissue
they cant divide and regenerate
liver shrinks
cant deal with toxins as effectively
