Lecture 6 - Liver and Bile Flashcards
(42 cards)
How much cardiac output does the liver receive
25%
The liver is multipurpose, a few of its functions…
- Exocrine organ (bile acid secretion)
- Storage organ (glycogen, iron)
- Endocrine organ
- Metabolism/detoxification
Where do absorbed nutrients go before delivery to peripheral tissues
Liver
What nutrients does the liver process
- Carbohydrates (glycogenesis/gluconeogenesis/glycogenolysis)
- AA -> functional proteins/pre-hormones
- Store vitamins
- Triglyceride handling
Uses of glucose in the liver of non-ruminants
Glycogen synthesis, f.a. synthesis
New glucose (gluconeogenesis) is formed from
Propionate, lactate, aa
Difference between amylose and amylopectin
Amylopectin is branched, easier to get glucose from it
Both starch
What does the liver synthesize triglycerides from
Fatty acids that were synthesized in the liver (non-ruminants)
F.a. mobilized from adipose tissue
What fats does the liver synthesize
Triglycerides
Lipoproteins (VLDL)
Ketones
Function of lipoproteins
Transport TG around body
What does the liver synthesize with regards to proteins
Non-essential amino acids
Which aa can the liver synthesize
Tyrosine from phenylalanine
Cysteine from methionine
Glutamate from glutamine
What is phenylketonuria
Lack of enzyme that converts phenylalanine to tyrosine = phe accumulates (toxic to brain) = brain damage
How does the liver detoxify ammonia
Urea production
Glutamine production
Things the liver is responsible for synthesizing
- Albumin
- Coagulation factors
- Transport proteins
- Immunologic proteins (e.g. complement)
- Bile salts
What is albumin? Responsible for…
Protein that transports non-esterified f.a. and drugs
Responsible for colloid osmotic pressures of plasma (keeps water in blood)
What happens when albumin is deficient
Colloid osmotic pressure fails = edema (swelling)
Proteins the liver makes responsible for blood clotting…
Fibrinogen, prothrombin
Protein made by liver that does iron transport
Transferrin
How does the liver function in protection?
- Prevents bacteremia (bacteria that get across gut barrier)
- Breakdown toxins and hormones
What kinds of toxins does the liver metabolize
Drugs and xenobiotics
How does the liver clear drugs etc from the body
Makes them hydrophilic (converts non-ionic to anions)
This facilitates excretion by the kidney (cannot cross membranes) and prevents reabsorption
If given meds, what must you do in terms of the liver to prevent excretion
Inhibit the liver enzyme responsible
Are substances bound to proteins cleared by the kidneys?
No, the liver
