Liver Flashcards
1
Q
Major Functions of Liver
A
- First site of processing
- most absorbed nutrients
- Site of detoxification (phase 1-3)
- Metabolism of toxic compounds, drugs
- convert to excretable substances
- Synthesis and secertion of bile & bile products
- Synthesis of:
- cholesterol
- steroid hormones
- proteins
- amino acids
- vitamins
- Glycogen
- High metabolic level of:
- carbohydrates
- lipids
- proteins
- amino acids
2
Q
Zone 1, 2, 3
A
- Zone 1 cells (outer layer): Cytochrome p450 enzymes-oxidation and hydroxylation
- most sensitive to toxic substances
- closest to triad
- greatest supply of nutrients and O2
- most active in detoxification
- Zone 2 cells (middle): Conjugation w/water soluble molecules
- respond to blood
- in between portal and central vein
- Zone 3 cells (inner)
- Excretion with bile
- excretion in feces, and urine if molecules are small enough
- not reabsorbed by intestines
- most active in bile synthesis
- Excretion with bile
3
Q
How does blood enter and leave the liver?
A
- Enter: 2 sources
- Hepatic Artery
- Hepatic Portal vein
- Leaves:
- Hepatic Vein
4
Q
Bile Pathways
A
- Bile synthesized in the liver
- secreted into common hepatic duct
- for storage in the gallbladder
- Gallbladder–>common bile duct–>lumen of intestine
5
Q
Causes of Abnormal Liver Function
A
- Hepatitis
- Fibrosis
- Cirrhosis
- Portal hypertension
6
Q
Hepatic Portal Vein
A
- Absorbed from GI Tract to liver
- billirubin
- nutrients
- Drugs
- Foreign Substances
7
Q
Hepatic Artery:
A
- Metabolites and drugs from peripheral tissues to liver
- bilirubin
- nutrients
- metabolites of hormones and drugs
8
Q
Hepatic Vein
A
- Blood leaving the liver: Metabolites to peripheral tissues
- glucose
- plasma proteins
- Albumin
- clotting factors
- angiotensinogen
- Urea
- Vitamin D
- somatomedins
- Metabolites for excretion
9
Q
Bile Duct
A
- liver produces bile and secretes into duodenum
- bile salts
- bilirubin
- water, ions
- phospholipids
10
Q
Jobs of liver
A
- Glucose and Fat metabolism
- Protein Synthesis
- Hormone synthesis
- Urea production
- detoxification
- Storage
11
Q
Lobules
A
- irregular hexagonal units of hepatocytes
- Centered around a central vein
- drains into hepatic vein
- Periphery=Hepatic triad
- hepatic portal vein
- Hepatic artery
- Bile ductule
12
Q
Significance of Kupfer Cells
A
- Macrophages
- line the walls of the sinusoids
- break down RBCs and split hemoglobin and breakdown heme into iron and bilirubin
13
Q
Stellate Cells
A
- found in space of disse
- storage unit for retinoids
- source of growth factors for hepatocytes
- Abnormal–produce large amounts of collagen=hepatic dysfunction
14
Q
Cholangiocytes
A
- classic columnar epithelial cells
15
Q
Tight Junctions
A
- leaky
- water and ions are drawn into canalicular lumen @ concentratin equal to plasma
- glucose
- calcium glutathione
- amino acids urea
