Chapter 7- Function Of Liver Flashcards
(18 cards)
The hepatic portal veins divide into - What are sinusoids?
Like capillaries but are wider and are not lined with cells- allows blood flowing to come into contact with hepatocytes (liver cel) - also allows proteins to enter and leave body
What does the hepatic artery divide into?
Arteioles which join with the sinusoids at various points
What is One of the main functions of the liver
To regulate the quantity of nutrients circulating in the blood
What is another key role of the liver
It plays a key role in the regulation of circulating glucose by either store and glucose as glycogen or break and glycogen down to glucose
Excess amino acid is broken down in the liver
WhaT is the liver responsible for
Liver is responsible for managing circulating lipids which arrive in a variety of forms- The liver processes lipids in one form and distributes it in another
When are nutrients stored in the liver and give an example
When they are in excess
Iron, vitamin A, vitamin D are stored in liver when in excess and released when there is a deficit
What happens to red blood cells at the end of their life?
Old and damage red blood cells are removed from circulation and a broken down in the spleen and in the liver
Explain the role by Kupffer cells in the breakdown of ted blood cells
They are engulfed by kupffer cells which are macrophages which line the sinusoids of the liver - inside cell, haemoglobin molecule is split into glob in chain and a heme group - amino acids from chain are recycled - while heme group is further broken down into iron and bilirubin- bilirubin is released back into blood
Iron is bound and transported to liver and spleen for storage or to bone marrow to help wth synthesis of new red blood cells
Explain how iron is transferred to new red blood cells
Travels to bone marrow bound to a protein
Cells have receptors for the carrier protein and red blood cells have high levels of this proteins revellers
Once blind the receptors iron complex enters the cell and the iron is incorporated into the heme molecule or is transferred to a storage molecule
Causes of jaundice
When a disease interferes with the normal metabolism or excretion of bilirubin, it can build up in the blood- result is jaundice
symptom- yellowing of the eyes and skin
Occur due to obstruction of bile duct by gallstone or pancreatic cancer
Causes of newborn jaundice
1) newborns have high turnover of red looks cells
2) newborns liver is often still developing and may not be able to process the bilirubin fast enough
3) some newborns don’t feed properly and lack of intestinal contents means excreted bilirubin cannot be reabsorbed
Treatment of jaundice/ consequence
Bili therapy
Exposure to ultraviolet rays
Neurological damage called kernicterus which is brain damage results in deafness and cerebral palsy
Adults- itchiness
What is surplus bile converted to?
Bile salts
What do endoplasmic reticulum and Golgi apparatus in hepatocytes produce?
Plasma proteins
Why does the fact that heptocytes are actively involved in protein synthesis explain the characteristics appearance of hepatocytes?
They show extensive networks of ER and Golgi body providing evidence of high levels protein synthesis
What does the liver remove?
Toxins from the body and detoxifies them
Give 2 examples of the liver breaking down toxic substances
Alcohol- less toxic substance by enzyme - ethanol dehydrogenase
Ammonia - urea
What are the two blood supplies to the liver?
Hepatic artery- branches off from aorta brining oxygen rich blood from the heart
Hepatic portal vein- brjngs blood from stomach and intestines to the liver- blood can be rich in nutrients- oxygen count is low
