Lec 16: Intro To Liver Flashcards
The liver is located beneath and attached to the ______, protected by the _____, and held in
place by _____.
- Diaphragm
- lower rib cage
- ligamentous attachments
The liver is divided unequally into two lobes by the ______________, or equally into two by the ______________
- Falciform ligament
- Line of Cantlie
Liver is an extremely vascular organ that receives its blood
supply from what two major sources?
Hepatic portal vein (75% blood), hepatic artery (25%)
Give the correct order of blood flow starting from the Portal triad until the systemic circulation
portal triad —> the sinusoids —> central vein —> hepatic veins —> inferior vena cava —> heart —> lungs —> heart —> the rest of the body
- Portal triad consists of ___.
- Two major cell types (liver)
- Hepatic artery, Portal vein, Bile duct
- Hepatocytes, Kupffer cells
4 major functions of Liver
- Excretion & secretion
- metabolism
- detoxification
- storage
- The pigment formed from the degradation of RBCs.
- Lifespan of RBC.
- The pigment released from RBC destruction/hemolysis.
- Bilirubin
- 120 days
- Hemoglobin (main pigment of RBC)
- Hemoglobin is separated into ___ & heme.
- Heme is separated into ___ by enzyme ___.
- The main product of Heme is reduced by enzyme ___ into unconjugated Bilirubin.
- What carrier protein does unconjugated bilirubin bind to in order to travel from blood to liver?
- The protein that transports Unconjugated bilirubin into the hepatocytes.
- Globin
-
Products: CO, Iron, porphyrin ring, biliverdin
Enzyme: Heme oxygenase - Biliverdin reductase
- Albumin
- Ligandin
- The enzyme that conjugates the unconjugated bilirubin.
- Product of conjugation
- Conjugated bilirubin will be excreted in bile which will be stored in the ___.
- The bilirubin released in the intestine is converted into a colorless pigment called ___ by ____.
- UDPGT
• adds glucuronic acid to bilirubin - Bilirubin diglucuronide / conjugated bilirubin
- Gallbladder
- Urobilinogen, GI trapped bacteria
Urobilinogen (pathways)
- Converted to stercobilin for feces color
- Absorbed into blood and excreted in urine as urobilinogen
- Converted to urobilin pigment
- Enterohepatic Recirculation
• reabsorbed in blood then returns to liver
Differentiate Conjugated and Unconjugated bilirubin
- Solubility
- Toxicity
Unconjugated bilirubin
1. Fat soluble
2. Toxic
• Can cross fatty nervous tissue & blood-brain barrier
• especially to brain —> Kernicterus
Conjugated bilirubin
1. Water soluble
2. Not toxic
- An unconjugated bilirubin that is covalently bound to albumin.
- It is seen in significant Hepatic obstruction.
- It reacts in lab methods as conjugated bilirubin.
Delta bilirubin
Composition of Total bilirubin
• unconjugated bilirubin (a-bilirubin) (indirect)
• monoglucuronide bilirubin (b-bilirubin)
• conjugated/diglucuronide bilirubin (y-bilirubin) (direct)
• Delta bilirubin
Liver metabolizes carbohydrates, FA or lipids, Amino acid & protein
Carbohydrate is broken down into glucose. What are the 3 methods/ways the liver can process glucose?
- Glucose —> pyruvate —(enters)—> TCA or Krebs’s cycle = more ATP
- Circulated throughout the body
- Stored as glycogen
Almost all proteins are synthesized by the liver except ___.
- Immunoglobulin & antibodies
• formed by lymphocytes - Adult hemoglobin
• synthesized by precursor cells
TRANSAMINATION
- Alanine
• enzyme
• co-enzyme
• products - Aspartate
• enzyme
• co-enzyme
• products
-
Alanine
• Alanine aminotransferase (ALT)
• Pyridoxam-5-phosphate
• pyruvate & glutamate -
Aspartate
• Aspartate aminotransferase (AST)
• Pyridoxam-5-phosphate
• oxaloacetate & glutamate
- Describe transamination reaction
- After transamination, deamination degrades them to produce ________ ions that are consumed in the synthesis of ______, which is excreted by the ________.
- Amino groups are transferred from amino acid to alpha-keto acid with the help of coenzyme PLP.
- Ammonium ions
Urea
Kidneys