Physiology and pharmacology of the liver Flashcards by K M

What is the metabolic hub of the body?

The Liver

How well did you know this?

Not at all

Perfectly

What metabolism does the liver regulate?

Carbohydrate
Lipid
Amino Acid

How well did you know this?

Not at all

Perfectly

What are the 4 steps of carbohydrate metabolism?

Glucogenesis
Glycolysis
Glycogenesis
Glycogenolysis

How well did you know this?

Not at all

Perfectly

What are the steps for fat metabolism?

Processing of chylomicron remnants
Synthesis of lipoproteins and cholesterol
Ketogenesis

How well did you know this?

Not at all

Perfectly

What are the steps of protein metabolism?

Synthesis of plasma proteins
Transamination and deamination of amino acid
conversion of ammonia to urea

How well did you know this?

Not at all

Perfectly

Many important hormones are de/activated by the liver True/false?

True

How well did you know this?

Not at all

Perfectly

What is deactivated by the liver?

Insulin
Glucagon
Anti-diuretic hormone (ADH)
Steroid hormone

How well did you know this?

Not at all

Perfectly

What is activated by the liver?

Conversion of thyroid hormone to triiodothyronine

Conversion of vitamin D to 25-hydroxyvitamin D2

How well did you know this?

Not at all

Perfectly

What does the liver store?

Fat soluble vitamins (ADEK)
Water soluble vitamin B12
Iron
Copper
Glycogen

How well did you know this?

Not at all

Perfectly

Where is vitamin A stored?

In ito cells

How well did you know this?

Not at all

Perfectly

Where is vitamin K stored?

Hepatocytes

How well did you know this?

Not at all

Perfectly

What proteins does the liver synthesize?

Coagulation factors 2,7,9 and 10
Proteins C+S
Albumin
Complement proteins
Apolipoproteins
Carrier proteins - a protein which combine to other molecules and carry them round the body

How well did you know this?

Not at all

Perfectly

What are factors that protect the liver?

Kupffer cells

Production of immune factors: Acute phase proteins

How well did you know this?

Not at all

Perfectly

What are Kupffer cells and what is their role?

Liver Phagocytes

Digest and destroy cellular debris and invading bacteria

How well did you know this?

Not at all

Perfectly

What is the liver involved in the detoxification of?

Endogenous (Bilirubin) and exogenous substances (Drugs/alcohol)

How well did you know this?

Not at all

Perfectly

What is the role of bile?

Participation in the digestion and absorption of fatzs and the exretion of products of metabolism

How well did you know this?

Not at all

Perfectly

How much bile is produced each day?

0.6-1.2L

What are the two types of bile?

Hepatic (Hepatocytes)

Secretory (Cholangiocytes)

Between meals where does bile reside?

Stored in the gall bladder due to the sphincter of oddi being closed

What does the gallbladder do to bile?

Removes water

Can cause solids to precipitate out (cholesterol) leading to gall stones

What happens to bile during a meal?

Chyme in duodenum stimulates gall bladder smooth muscle to contract (via CCK and Vagal impulses)
Sphincter of oddi opens (Via CCK)
Bile spurts into duodenum via cystic and common bile ducts

What is gallbladder secretion high in?

Bicarbonate

What does slightly alkaline bile assist in?

Protection of the gastric mucosa

What does bile contain?

Secretion of hepatocytes
Secretion of bile ducts (cholangiocytes)
Bile acids (cholic and chenodeoxycholic)
Water and electrocytes
Lipids and phospholipids
Cholesterol
IgA
Bilirubiin

What is bilirubin?

Breakdown product of porphyrin component of haemoglobin Pigment rendering urine yellow and faeces brown When present in excess causes jaundice

What is the process of bile secretion through the duodenum?

The hepatocytes produce two primary bile acids, these appear in the bile, during feeding they enter the duodenum with the rest of the bile, as it moves along the intestine, bacteria is encountered, bacteria then attacks the primary bile acids and converts them to the secondary bile acids. Both secondary and primary acids are reabsorbed where they return to the liver through the portal system where the process can begin again

What does the liver do when low in salt?

It uses Cholesterol

What is the most common pathology of the biliary tract?

Cholelithiasis

What is the best treatment for large, hard, calcified symptomatic gall stones?

Laparoscopic cholecystectomy

What is the treatment for non-calcified gall stones?

Ursodeoxycholic acid

When may potent analgesia be required?

Biliary colic

What drug relieves biliary spasm?

Atropine | GTN

What percentage of the bile salts that enter the duodenum are lost in faeces?

What occurs to the majority of the bile?

Most is reabsorbed by active transport in the terminal ileum and undergoes enterohepatic recycling

What are three bile acid sequestrants (resins)?

Colvesam Colestipol Colestyramine

Are the bile acid sequestrants (resins) absorbed or digested?

Neither, they bind to bile acids to prevent their reabsorption

What do the resins do?

Lower plasma LDL cholesterol indirectly Treating hyperlipidemia and cholestatic jaundice Bile acid diarrhoea

What are the disadvantages of resins?

Unpalatable and inconvinient GI side effects - frequently cause diarrhoea Deficiency of fat soluble vitamins

What occurs in phase I of drug metabolism in the liver?

Oxidation (Mediated by cytochrome P450's) Reduction Hydrolysis Adds a polar group to the compound to causes one of these reactions to occur

What does it mean when a drug is Lipiphyllic?

Difficult for the kidney to excrete | Stay in the body for a long time

What is phase 2 of drug metabolism in the liver?

Conjugation Adds an endogenous compound increasing the polarity of a drug with glucaronyl, sulphate, methyl, acetyl, glycyl etc. Makes them more readily excretable for the body