Excretion Flashcards
What are the liver cells called?
Hepatocytes
How is the liver supplied with blood?
Via the hepatic artery and the hepatic portal vein
What is the function of the hepatic artery?
Oxygenated blood is supplied from the aorta via this artery. Supplies oxygen for aerobic respiration.
What is the function of hepatic portal vein?
Deoxygenated blood from the digestive system enters here from the intestine. This blood is rich in the products of digestion. The blood may also contain toxic compounds. The concentrations in the blood here will be uncontrolled
Where does blood leave the liver and go?
Blood leaves via the hepatic vein and rejoins the vena cava.
What is the fourth vessel connected to the liver?
The bile duct
What is the function of the bile duct?
Bile is secreted from the liver to be used in digestion and excretion. The bile duct carries the bile to the gall bladder.
Why does bile go to the gall bladder?
To be stored until required to aid digestion of fats in the small intestine.
What does bile contain?
Excretory products such as bile pigments like bilirubin which will leave the body with faeces
How is the liver divided?
Into lobes which are dither divided into lobules.
What are the 3 structures to label in a microscopic image of the liver lobules?
Inter lobular vessel
Intra-lobular vessel
Liver lobule
What are the inter-lobular vessels?
The smaller vessels that the hepatic artery and hepatic portal vein split into where they enter the liver. They run between and parallel to the lobules.
What is the sinusoid?
Lined with liver cells
The blood from both the hepatic portal vein and hepatic artery flows along here in close contact with liver cells.
What can the liver cells in contact with the sinusoid do?
They can remove substances from the blood and return other substances to the blood.
What are kupffer cells?
Specialised macrophages that can move about with the sinusoids?
What is the function of kupffer cells?
To breakdown and recycle old red blood cells.
What is the product of haemoglobin?
Bilirubin
What forms the bile duct?
The bile canaliculi
What has happened to the blood by the end of the sinusoid?
The concentrations of the blood components have been modified and regulated.
What is found at the centre of each lobule?
A branch of the hepatic vein known as the intra-lobular vessel.
Describe hepatocytes?
Cuboidal shape
Have many microvilli on the surface
Dense cytoplasm
Metabolic functions that occur in hepatocytes?
Protein synthesis
Transformation and storage of carbohydrates
Synthesis of cholesterol and bile salts
Detoxification
Liver functions?
Detoxification of alcohol and drugs
Breakdown of hormone
Destruction of red blood cells
What levels are controlled by the liver?
Glucose levels
Amino acid levels
Lipid levels
What does the liver synthesise?
Bile
Plasma proteins
Cholesterol
Red blood cells in the fetus
What does the liver store?
Vitamins A, D and B12
Iron
Glycogen
Enzymes contained by liver?
Catalase
Cytochrome P450