Liver Flashcards
(39 cards)
Where is the liver located?
URQ, beneath diaphragm and behind lower ribs
How much does the liver weigh?
1500 g (3 lbs, size of football) -aka LARGEST internal organ
What is the major function of the liver?
Excretion of waste products from the bloodstream by excretion into bile
-detoxification by splenic blood
What are the 3 basic functions of the liver?
1) Metabolic- processing of dietary AAs, carbs, lipids and vitamins; synthesis of plasma proteins; synthesis of bile
2) Secretory
3) Vascular
What is the function of the hepatic artery?
Provides 20-30% of O2-RICH blood supply to liver
-Liver is a vascular organ
What is the function of the portal vein?
Provides 70-80% of NUTRIENT-RICH (O2-poor) blood supply to liver
-Drains from the digestive tract via the splenic vein and superior mesentric vein
What are the lobes of the liver?
4 lobes: RT (largest lobe), LT, quadrate and caudate lobes
How is the liver connected to the diaphragm and abdominal walls?
5 ligaments: Falciform ligament, Teres ligament, Coronary ligament, RT and LT triangular ligaments
What is unique to the liver?
Only human organ with self-regeneration; only have to donate a small piece
What are Kuppfer cells?
Phagocytic cells of the liver that ingest toxins and waste products of metabolism
What are sinusoids?
Fenestrated vessels (porous), wider than capillaries; lined w/ endothelial cells
- Allow for mixing of O2-rich blood from hepatic artery and nutrient-rich blood from portal vein
- Do all the work
The liver has Kuppfer cells and ___ cells.
Fat storing
How do blood and bile flow to and from the liver?
In OPPOSITE directions
- Blood flow: deoxygenated blood from stomach or small intestine -> hepatic portal vein -> venules -> sinusoids -> central vein -> hepatic vein -> vena cava
- Bile flow: bile produced in hepatocytes -> secreted into canaliculi -> bile ductules -> common duct -> gallbladder -> bile duct -> small intestine
What is the liver role in nutrient storage?
Hepatocytes absorb and store excess nutrients in the blood
-Glucose (stored as glycogen), iron, retinol (vitamin A), calciferol (vitamin D)
How are erythrocytes broken down in liver?
Hemoglobin is absorbed by phagocytosis by Kuppfer cells in the liver; Hb split into:
1) Heme groups -> iron is removed from a heme leaving a substance called bilirubin (bile pigment)
2) Globins -> hydrolyzed to AAs and returned to blood
What happens if hemoglobin is not absorbed by Kuppfer cells?
Too much iron -> buildup causes toxicity of liver -> Hemochromotosis
What is the life span of a normal, healthy RBC?
120 days
What does glucagon do?
Raises blood sugar by stimulating the breakdown of glycogen
Where are plasma proteins synthesized?
In the rER of hepatocytes
What are the 3 main types of plasma proteins synthesized by the liver?
Albumin, globulin, fibrinogen
What happens if you have less synthesis of plasma proteins?
Hypoalbuminemia-> Third spacing of fluid (this happens in liver disease) -> Peripheral edema (poor quality of life, increased chance of infection because of tapping of fluid and peritonitis)
If less plasma proteins are synthesized in liver disease, how should a patient’s medication be altered?
Patient should be given a lower dose to avoid toxicity
-Medications are active when they are “free floating” through the blood, they are inactivated when they are bound to plasma proteins (less plasma proteins -> more free floating)
Where is cholesterol made?
In hepatocytes in the liver
What is cholesterol the precursor for?
Steroid hormones made by the testis, ovaries or adrenal gland (progestins, glucocortoids, androgens, estrogens, mineralocortoids); also Vitamin D
