Liver Flashcards
What is homeostasis?
a self regulating process where biological systems maintain internal stability/equilibrium while adjusting to changing external conditions
Where are temperature receptors in our brain?
hypothalamus
How do endotherms cool?
-sweating by sweat glands
-reduce insulation of hair by erector muscles relaxing so they lay flat
-vasodilation by arterioles dilating
How do endotherms warm?
-vasoconstriction by arterioles constricting
-decreased sweating
-raising body hairs to increases insulation by erector muscles contracting
-shivering by relaxing and contracting muscles, metabolic heat from the exothermic reactions involved increases heat
-hibernation
-some have small SA:V to reduce heat loss
How to ectotherms regulate temperature?
- bask in the sun
-press their bodies against warm ground
-exothermic metabolic reactions
-alter heart rate
-dark colours
What is excretion?
removal of metabolic waste
What are the main metabolic waste products in mammals?
CO2
bile pigments
urea
What are the main metabolic waste products in mammals?
CO2
bile pigments
urea
Which arteries are connected with the liver?
hepatic artery
hepatic vein
hepatic portal vein
What are liver cells called?
hepatocytes
What are the features of hepatocytes?
large nuclei
prominent golgi
lots mitrochondria
What can the liver do if part of it is damaged?
regenerate
What does the hepatic artery do?
supplies the liver with oxygen
What does the hepatic vein do?
takes deoxygenated blood away
What does the hepatic portal vein do?
brings blood from the duodenum and intestine
What is a liver lobule made up of?
hepatocytes that radiate from the central vein which is a branch of the hepatic vein
What is the lobule connected to?
bile duct
hepatic artery
hepatic portal vein
Where is the blood mixed from the hepatic portal vein and hepatic artery?
sinusoids
What do sinusoids contain?
Kupffer cells
What are Kupffer cells?
macrophages of the liver which ingest foreign particles
What is bile formed from?
break down of blood
Where is bile secreted into to drain into the bile ducts?
canaliculi
What are 3 functions of the liver?
-carbohydrate metabolism
-deamination of excess amino acids
- detoxification
What does the liver convert glucose to and store?
glycogen
What is it called when one amino acid is converted into another?
transamination
What is deamination?
the removal of amine group as the body cannot store proteins
The amine group is converted to ammonia
What happens in the ornithine cycle?
ammonia is combined with CO2 to produce urea
What is hydrogen peroxide broken down by and into?
In the hepatocytes by catalase into oxygen and water
What is ethanol broken down by and into?
Broken down by alcohol dehydrogenase into ethanal then ethanoate which can be used by the body
What is liver tissue normally stained with when looking at it under a microscope?
Eosin or haematoxylin
