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Flashcards in Liver And Gsll Bladder Function Deck (15):
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Liver functions

Bile production
Metabolism
Detoxification

1

Major constituents of bile

250-1500mls of bile per day
Bile salts
Phospholipids (lectilnin)
Bile pigment (bilirubin)
Cholesterol
Inorganic ions

2

Bile salts

Derivatives of cholesterol
Important for lipid digestion and absorption
Enterohepatic recycling

3

Enterohepatic recycling

Bile salts produced by liver, drain in to gall bladder
Enter small intestines via common bile duct
95% of bile salts reabsorbed into hepatic portal vein
5% lost in faeces
Bile salts returned to liver

4

Excretion of bile pigments

Major breakdown product of Haemoglobin
Conjugated with glucuronic acid-> increases polarity and solubility
Transported to liver bound to plasma albumin
Bilirubin glucuranide is broken down by bacteria to form bilirubin
Combined with H2 to form urobilinogen
Recycled from intestine in portal system or excreted in systemic
Cholesterol is the major excretion site of bile
Inorganic ions accompany osmotic effect of bile acid secretion

5

Role of the gall bladder in storing and secreting bile

Rate of production is dependent on hepatocyte secretions
Resting-> flow in to duodenum prevented by closer of sphincter of oddi-> in to gall bladder
Bile becomes concentrated due to reabsorption of salts and water in the gall bladder
Neural and CCK release stimulated by fat in duodenum-> relax sphincter of oddi, contracts gall bladder-> bile into duodenum

6

Functions of the liver

Detoxification
Metabolism:
Plasma glucose/amino acid concentrations-> absorbed nutrients pass through portal circulation
Fructose and galactose to glucose
Glucose taken up by liver-> glycogen-> stored or triacylglycerol
Fats+protein-> lipoproteins released
Remainder of glucose is taken up by adipose
Synthesis of albumin and clotting factors
Storage of fat soluble vitamins, iron, copper

7

Detoxification

Multiple enzyme systems allow modification of chemical structures
Generally aim to increase water solubility
Endogenous-> insulin, glucagon, aldosterone, female sex hormones
Exogenous-> drugs
Phase 1-> oxidation/reduction
Phase 2-> methylation, conjugation
Produce-> acetic acid, amino acid, sulphate, glucuronic acid

8

Jaundice

Bilirubin accumulation in plasma
Greater than 59mM
Yellowing of skin, sclera and mucous membranes
Hernicterus-> deposits in the brain-> nerve degeneration
Treat with light

9

Haemolytic jaundice

Excessive haemolysis of RBC's-> overwhelms liver capacity

10

Intra hepatic jaundice

defect in uptake or conjugation or secretion of bilirubin by hepatic cells

11

Obstructive jaundice

Blockage of bile ducts

12

Physiological jaundice

New borne
Poor bilirubin conjugating

13

Hepatitis

Infection/inflammation of the liver
Acute-> viral, drugs
Chronic-> 6 months viral B and C

14

Cirrhosis

Necrosis of the liver cells
Replaced by fibroblasts
Alcohol and hep B and C
Irreversible