The Hepatic System Flashcards
1
Q
What are the two sources of blood supply to the liver?
A
- 1/3 blood supply to liver is from the hepatic artery
- 2/3 is venous blood from hepatic portal vein
2
Q
What is the hepatic portal system?
A
- Carries blood rich in nutrients absorbed from food
- Begins in the capillaries of the GIT-Anything that is absorbed by the GIT travels to the liver before it enter the systemic circulation
- Ends in liver sinusoids
- Largest vessel is the hepatic portal vein
2
Q
What is the function of the hepatic portal vein?
A
- HPV carries blood rich in nutrients absorbed from food
- Filters toxins absorbed along with food
- First pass metabolism
- Conc. of drug greatly reduced before it enters systemic circulation
- Reduced bioavailability
3
Q
What is a lobule?
A
A lobule is the basic functional unit of the liver
* Lobules are composed of hepatocytes
* Hepatocytes form series of irregular plates
4
Q
What are the functions of the liver?
A
- Metabolic regulation
- Haematological regulation
- Bile production
5
Q
What is metabolic reproduction?
A
- Regulates composition of circulating blood
6
Q
What is Haematological regulation?
A
- Phagocytosis and immune response
- Synthesis of plasma proteins
- Removal of circulating hormones
- Removal of antibodies
- Kupffer cells in sinusoids remove old or damaged RBS, pathogens etc
- Synthesise of albumin, clotting proteins, complement proteins, transport proteins
- Hormones such as adrenaline, noradren, insulin, thyroid hormones, sex hormones
7
Q
How is bile produced?
A
- Secreted into duodenum
(Bile composed of water, bilirubin, ions, cholesterol
and bile salts)
-Dietary lipids are not water soluble - In the stomach large lipid droplets are produced
Pancreatic lipase acts on surface lipids
Bile emulsifies lipids
8
Q
What is the gallbladder?
A
A hollow, pear-shaped organ, which stores and concentrates bile.
9
Q
What hormone controls the gallbladder?
A
-Cholecystokinin (CCK)
-The conc. of CCK released is proportional to lipid conc. in chyme
