Flashcards in F214:02:02 The Liver Deck (32):
What is the hepatic portal vein
It is an unusual blood vessel that has capillaries at both ends
It carries blood from the digestive system to the liver
What are liver cells known as/
Why is it important that hepatocytes have a good supply of blood?
As they carry out hundreds of metabollic processes and they play an important role in the maintenance of homeostasis.
Where is the blood supplied from that enters the liver?
Oxygenated blood comes from the heart
Deoxygenated blood enters from the digestive system
How does blood from the heart enter the liver?
Travels from the aorta via the hepatic artery into the liver
Why does the liver require blood from the heart?
As it is essential for aerobic respiration , as many processes require energy in the form of ATP so a lot of oxygen is required.
How does deoxygenated blood enter the liver?
Enters via the hepatic portal vein
Why is deoxygenated blood useful in the liver?
As it is rich in the products of digestion, but the concentrations of various compounds will be uncontrolled, and the blood may contain toxic compounds that have been absorbed in the intestine
How does the blood leave the liver?
Blood passes along a special chamber called a sinusoid which floods into the intra-lobular vessel
(a branch of the hepatic vein) which rejoins the vena cava and the blood returns to the normal circulation round the body
What is the fourth vesselto be connected to the liver?
The bile duct (NOT A BLOOD VESSEL)
What is bile?
secretion from the liver
What is the role of bile?
Has a digestive and excretory function,
Digests fats in the small intestine
Where is bile stored?
Bile is carried by the bile duct from the liver to the gall bladder until it is needed
Describe the arrangement within the liver
The liver is split up into lobes, which are further divided into lobules
Why are the cells within the liver specifically arranged in a certain way?
To ensure the maximum amount of contact between the blood and the liver
What happens to the hepatic vein and hepatic portal vein as they enter the liver?
They become inter-lobular vessels
They split into smaller and smaller vessels that run between and parallel to the lobules
How does blood enter lobules in the liver?
As at intervals, branches from the hepatic artery and hepatic portal vein enter them
Why does blood enter the lobules from both the hepatic artery and the hepatic portal vein?
As the two types of blood have different qualities
What is the sinusoid in very close contact with and why is this vital?
As the liver cells are able to remove molecules from the blood and add others into the blood
Where is bile manufactured?
in the liver
What happens to bile once it has been manufactured?
It is released into the bile canaliculi which all join together to form the bile duct, transporting bile to the gall bladder
What are bile canaliculi?
small canals that join together to form the bile duct
Describe a typical liver cell
Simple cuboidal shape with many microvilli on their surface
What are the main metabolic functions of the liver?
transformation and storage of carbohydrates
synthesis of cholesterol and bile salts
Why is the cytoplasm of hepatocytes very dense?
because it has so many metabolic functions
What are Kupffer cells?
What is the primary function of Kupffer cells?
the breakdown and recycling of old RBC
Where are Kupffer cells found?
moving within the sinusoids
What is bilirubin?
one of the waste products from haemoglobin
The brown pigment in faeces
Explain why the liver has two supplies of blood
1. Deoxygenated blood that has come from the digestive system, removing excess amino acids/glucose/alcohol and any other toxic compounds that dont want to be circulated round the body
2. Oxygenated blood supplies oxygen for aerobic resp.
Describe how the liver structure ensures that the blood flows past as many liver cells as possible
Blood entering liver flows into even smaller vessels
Blood has two sources and mixes together and flows along the sinusoids