3B-Physiology of the LIVer Flashcards by Austin Shackelford

You ready for the BOOM?! How bad do you want that A?! WHAT ARE THE 13 MAJOR LIVER FUNCTIONS? This is a mastery type flashcard..

1.GlycogenoLYSIS 2.Glycogenesis 3.Protein Metabolism 4.Urea Synthesis 5.Lipid Metabolism 6.Hormone Metabolism 7.Iron Metabolism/Storage 8.Vitamin Storage 9. Drug Detoxification 10. Vitamin D Activation 11. Plasma Protein Synthesis 12. Clotting Factor Synthesis 13. Bile Synthesis

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Liver cells can typically store up to ___% of their weight as glycogen (____-____ g in an adult).

8%…100-120g

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Which tissue stores more TOTAL glycogen: liver or skeletal muscle? In the muscles, glycogen is found in a much lower concentration then the liver (___-____% of the muscle mass).

Skeletal Muscle….1-3%

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What is the first step to amino acid degradation?

DEAMINATION! Remove the AMINE group from the AA

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What 2 enzymes are required for the first step in amino acid degradation?

1.Aspartate TransAminase (AST) 2.Alanine TransAminase (ALT)

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What are the 2 roles of the enzymes AST and ALT?

Deaminate Amino Acids 2.Synthesize non-essential AA’s in the liver

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High blood levels of ____ (SGPT) and ____ (SGOT) can be indicative of liver disease.

AST & ALT

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Ultimately, the amine groups cleaved from the amino acids are converted into _______ (___) or ________ (____), which are then converted into ____.

ammonia (NH3) or ammonium ions (NH4+)…..urea

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Where does Urea synthesis occur?

the liver

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What is the name of the cycle where ammonia is converted into urea?

the Anders ÖRN-ith-ine Cycle!

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What is the diseased liver STATE caused by accumulation of AMMONIA in the blood? (two names)

Hepatic Coma or Hepatic Encephalopathy

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What is the diseased liver STATE caused by accumulation of UREA in the blood? (two names)

AZ-O-temia or Uremia

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What can be the result of a build up of urea in the body and it precipitates on the Pt’s skin?

Uremic Frost…Interesting!

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What is a BUN? What is a normal BUN range?

Blood Urea Nitrogen…5-26 mg/dL in adults

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What are the 4 ways BUN can be elevated? Whats the most common?

1.Impared Renal Function (MOST COMMON) 2.Increased Protein intake/catabolism 3. G.I. Bleeding (bacteria make Nitrogenous waste) 4. Dehydration

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Where are chylomicrons made? Where are most of them absorbed?

the Small Intestine…absorbed into the Lymph

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Which lipoproteins are carrying cholesterol/fats from the liver to the body? (2 types)

VLDLs and LDLs

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Which lipoproteins carry cholesterol/fats from the body and bring it to the liver?

HDL

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Which lipoprotein is the deflated beach ball?

HDL!

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WHAT IS THE CATALINA WINE MIXER of endogenous cholesterol synthesis?

HMG-CoA REDUCTASE!!

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What is the ONLY WAY the body gets rid of excess Cholesterol?

VIA the BILE (HDLs pick it up and bring it to the limbs)

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What is the main cause of Gall Stones?

TOO much Cholesterol in the Bile solution

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What are the two main causes of KetoGenesis?

1.Fasting State 2.Type I Diabetes

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REVIEW: What are the three Ketone Bodies?

1.Acetone 2.Beta-Hy-droxy-but-yric Acid 3.Aceto-Acetic Acid

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What are the three main types of hormones the liver degrades?

1.Steroid Hormones 2.T3 3.T4

What is the difference between T3 and T4?

An extra Iodine!

What molecule STORES iron in the liver?

Ferritin

What is the classic sign of Hema-Chromo-Cytosis?(high ferratin)

Bronzing of the Skin (not addison's disease)

What is the form of iron in the blood?

Transferrin

What does iron bind to in the liver to make its final storage complex (ferratin)? (we didn't discuss this)

Apo-ferritin + iron =ferritin, final storage form

What three vitamins are stored in LARGE quantities in the liver?

Vitamins A, B12, and D

What is the most important enzyme system in the liver for DRUG metabolism?

Cytochrome P450

The basic purpose of drug metabolism in the body is to make drugs less _______ and more _______ and thus more readily excreted in the _____ or _____.

less active....more water soluble.....urine or bile

Which enzymes are associated with Phase I in drug metabolism?

CytoChrome P450 enzymes

Which enzymes are associated with Phase II in drug metabolism?

Conjugate Enzymes

What can the drug possibly be split into in Phase 1 of drug metabolism?

1.A metabolite with modified activity 2.A metabolite that is inactive

The Cytochrome P450 enzymes are most predominant in the liver but can also be found in the ______, ______ and other organs.

intestines, lungs and other organs

Each CYP enzyme is termed an _____ since each derives from a different gene.

isoform

During Drug Metabolism, Conjugation reactions are designed to make metabolites more _____/_______, sometimes after they've been created by P450 enzymes.

polar/hydrophilic

What are the 4 endogenous substrates added to a metabolite during the conjugation phase? What is the most common one?

1.Glu-Cur-Onic Acid (AKA Glu-cur-on-idation= most common) 2.Gluta-thi-one 3.Acetyl-CoA 4. An Amino Acid

What DDI results in DECREASED metabolic activity of CP450 enzymes, leading to DECREASED metabolism of drugs?

CP450 INHIBITION...Grapefruit juice inhibits the metabolism of cocaine!

Which DDI results in INCREASED activity of CP450 enzymes leading to INCREASED metabolism of the drugs?

CP450 INDUCTION...Ethanol speeds up the metabolism of tylenol or BROCCOLI speeds up the metabolism of caffeine!

What is the final, active product of Vit D activation? What hormone stimulates the final steps?

1,25-Di-Hydroxy-chol-e-cal-ciferol...PTH

REVIEW: What are the three MAIN types of plasma proteins? Are these the only proteins found in the blood?

1. Albumin 2.Globulin 3.Fibrinogen...HELL NAW, not the only proteins found in the blood!

___-___% of the globulins are formed in the liver. The remainder of the globulins are formed almost entirely in the __________. They are mainly ______ globulins that constitute the antibodies used in the immune system.

50-80%...lymphoid tissues...Gamma

BOOM GO TIME: What are the 5 main functions of Plasma Proteins?

1.Oncotic Pressure(prevents edema) 2.Buffer 3. Transport(hydrophobic stuff, metals, what not) 4.Clotting 5.Immune response

WHAT ARE THE 9 clotting factors synthesized in the liver?

1,2-----5------7, 8, 9, 10, 11, 12...EASY as PIE!

What are the 6 constituents of bile? How much of bile is technically waste?

1. Bile Salts (50%) 2. Phospholipids (40%) 3.Cholesterol (4%) 4.Bile Pigments-Biliruben(2%) 5.Electrolytes 6.Water...50% is technically waste!!

What are the two PRIMARY Bile Acids? What are they synthesized by?

Cho-Lic Acid and Chen-o-deoxy-Cho-Lic Acid...Synthesized by the liver

What are the two SECONDARY bile acids? What are they synthesized by?

Deoxy-Cho-Lic Acid and Litho-Cho-Lic Acid... Synthesized by intestinal bacteria

What are the two AA's used to turn bile acid into bile salt?

GLYCINE or TAURINE

What is the purpose of conjugating bile acids into bile salts?

Makes them AMPHIPATHIC!

Which class of bile acid is found in the gall bladder? Which class gets converted to bile salts?

PRIMARY...cholic acid and chenodeoxycholic acid have not been exposed to the intestinal bacteria yet....Secondary get converted to the bile salt

What is the most common phospholipid found in bile?

Lecithin "LESS-EH-THIN"

Hepatic synthesis of ____ _____ accounts for the majority of cholesterol breakdown in the body.

bile acids

In humans, roughly ____ mg of cholesterol are converted to bile acids and eliminated in bile every day.

500 mg

Bilirubin is a waste product of _______ degradation.

Hemoglobin

What are the two types of bilirubin? (With ALL their names :))

1.Free/Unconjugated/Indirect Bilirubin and 2.Conjugated/Direct Bilirubin

_____ bilirubin is transported in the BLOOD attached to ALBUMIN.

Free/Unconjugated. Indirect

What are the three steps that a hepatocyte must do to turn free bilirubin to conjugated biliruben?

1.Uptake from circulation 2.Conjucation of the bilirubin 3.Excretion of bilirubin in bile

WHAT IS ATTACHED to bilirubin in order to CONJUGATE it?? What is the ENZYME that catylizes this RXN?

GLU-CUR-ONIC ACID...Glu-cur-onyl Transferase

Which is more water soluble: conjugated or free bilirubin?

Conjugated bilirubin is much more water soluble then free bilirubin.

What is the form of bilirubin in feces?

Sterobilin

What are the three steps to bile synthesis?

1.hepatocytes secrete bile into CANALICULI 2. water and HCO3 added to bile by CHOL-ANGIO-CYTES 3. 50% gets Stored inGall Bladder

The first two steps of bile synthesis may produce ___ ml/day of "_______"

900 ml/day of "hepatic bile"

What is the extremely aggressive form of cancer in the CholAngioCytes?

"bile duct" cancer

Between meals, approx. ____% the hepatic bile is diverted to the ________, which stores the bile and removes _____ and _____. Here the contents are increased __-___ fold.

50%....gall bladder....salts and water..10-20fold increase

So, during meals, the bile that reaches the duodenum is a mixture of relatively "dilute” _____ bile and “concentrated” ________ bile.

hepatic bile....gall bladder bile

What are the 2 important functions of Bile?

1.Excrete things the kidney can't 2.Lipid Digestion/Absorption