17 - Physiology of Liver & Pancreas Flashcards
What is the blood flow through the liver lobule starting in the portal vein?
Portal vein – Sinusoids – Central vein – Hepatic veins
What is the blood flow through the liver lobule starting in the hepatic artery?
Hepatic artery – Sinusoids – Central vein – Hepatic veins
Liver cell plates are composed of two layers of __________.
Hepatocytes
_______ _______ lie between the two layers of hepatocytes in each cell plate.
Bile canaliculi
Sinusoids are lined with what?
Endothelial cells
Kupffer cells
This is what is found between endothelial cells and hepatocytes.
Space of Disse
The liver has a (HIGH/LOW) blood flow and (HIGH/LOW) vascular resistance.
High
Low
_______ ml from the portal vein + _______ ml from the hepatic artery flows into sinusoids each minute.
1050
300
What percentage of the resting cardiac output is in the liver?
27 percent
What is the portal pressure into the liver?
9 mmHg
What is the pressure from the liver to the vena cava?
0 mmHg
________ increases blood resistance to blood flow.
Cirrhosis
The effect of a clot blocking the portal vein or a major branch results in the blockage of return blood from the _______ and _______.
Spleen
Intestines
The effect of a clot blocking the portal vein or a major branch can result in an (INCREASE/DECREASE) in capillary pressure in the intestinal wall, leading to loss of fluid and death.
Increase
The normal volume of the liver is _____ ml, which is _____ percent of the body’s blood volume.
450
10
What happens when there is high pressure in the right atrium in the occurrence of cardiac failure with peripheral congestion?
Causes backpressure on the liver and leads to increased blood volume in the liver up to 1.5 liters
T/F. The liver can store blood in times of excess and supply blood in times of diminished volume.
True
Hepatic sinusoids are highly permeable to ________.
Proteins
Higher than normal pressure in hepatic veins can cause a large amount of fluid in the abdominal cavity, which is called _________.
Ascites
Functions of carbohydrate metabolism in the liver includes:
- Storage of glucose as ________
- Converts _______ and _______ to glucose
- Gluconeogenesis
- Forms many intermediate products of carb metabolism
- Releases stored glucose into circulation
Glycogen
Galactose
Fructose
Functions of fat metabolism in the liver includes:
- Oxidation of ______ _____ for energy
- Synthesis of cholesterol, phospholipids, lipoproteins
- Synthesis of fats from proteins and carbohydrates
Fatty acids
Functions of protein metabolism in the liver includes:
- ________ of amino acids
- Formation of urea
- Formation of plasma proteins
- Interconversion of various amino acids and synthesis of other compounds from amino acids
Deamination
The liver stores what vitamins?
Vitamin A
Vitamin D
Vitamin B12
T/F. The liver does not possess any immune function.
False. It does have immune function.
The liver functions in the formation of which coagulation factors?
Fibrinogen
Prothrombin
Accelerator globulin
Factors VII, IX, X
The liver removes or excretes drugs, hormone, and other substances. It detoxifies or excretes it into the _______.
Bile
The liver excretes excess _______ into the bile.
Calcium
The liver also detoxifies and removes _______ and _______.
Ammonia
Ethanol
Potentially toxic substances are presented to the liver via the portal system. Phase I reactions are catalyzed by ______ enzymes, then Phase II reactions conjugate products from Phase I reactions and are excreted in the bile.
P-450
Sulfonamides, penicillin, ampicillin, and erythromycin are all excreted from the liver by the ______.
Bile
Note that bile is secreted continuously by hepatocytes in the liver and stored in the ______ ______ until needed.
Gall bladder
In the gall bladder, bile is concentrated by active transport of _______ followed by secondary absorption of _______ ions, _______, and other diffusible constituents.
Sodium
Chloride
Water
What factors stimulate the release of bile from the gall bladder?
Presence of fatty food in duodenum
Bile salts are amphipathic and orient themselves around lipid droplets to keep them dispersed, this is called __________.
Emulsification
Bile salts complex with lipids to form micelles. They are positioned on the outside of the micelles for absorption across ________ ________.
Intestinal mucosa
What are inside the micelles that are complexed with the bile salts?
Free fatty acids
Monoglycerides
What are the primary bile acids that are synthesized from cholesterol by hepatocytes?
Cholic acid
Chenodeoxycholic acid
Bacteria in the intestine convert the primary bile acids into secondary bile acids, which are…
Deoxycholic acid
Lithocholic acid
Bile acids are conjugated with ________ or ________ and electrolytes and water are added to bile.
Glycine
Taurine
Bile is (CONCENTRATED/DILUTED) in the gallbladder as a result of absorption of solutes and water.
Concentrated
Bile also contains pigments and organic molecules. The major pigment is ________.
Bilirubin
This is what is released from damaged RBCs.
Hemoglobin
Hemoglobin is phagocytized by macrophages (reticuloendothelial system). Here it is split into globin and heme. The heme ring is opened to free iron and is transported in the blood by transferrin. Straight chain of pyrrole nuclei is formed. Heme is converted by heme oxygenase into _________, which is then converted to free (unconjugated) bilirubin.
Biliverdin