Plasma Composition & Red Blood Cell Metabolism- Goueli Flashcards
How does cirrhosis of the liver lead to ascites? Mechanism?
The liver is responsible for synthesizing and releasing more than 90% of the plasma proteins….if it is damaged there will be less proteins in the blood which will disrupt the balance between osmolarity and hydrostatic pressure. End result is that fluid leaves the venous portion of the capilaries and builds up in the tissues…typically the oncotic pressure in the blood results in the fluid being reabsorbed in the vessels…..
What is ascites?
Fluid in the peritoneal cavity
How do you get hereditary spherocytosis?
Some sort of defect in the erythrocyte cytoskeletal proteins
What is your body’s #1 goal?
Get O2 into the tissue!
Explain the Starling forces (oncotic and hydrostatic pressure)?
- On the arterial end there’s more hydrostatic pressure than oncotic——> fluid leaves and goes into extravascular spaces
- On the venous end the hydrostatic pressure is decreased and the oncotic is the same——-> fluid from the extravascular spaces enters back into the blood
what is the major contributor to oncotic pressure?
Albumin, find this on comprehensive metabolic panel!
It also carries Ca2+ so that’s gonna be important to think about too someday
What should you give patients after doing a paracentesis?
Give them albumin! If you don’t their blood pressure will drop from the huge loss of fluid (albumin will keep fluid in the blood b/c osmolarity shiz….)
why do RBC’s have high surface area to volume ratio?
Rapid O2 absorption and faster gas exchange!
what does EPO do?
- Stimulates erythropoiesis! (along with a couple other hormones)
- Increases rate of Hb synthesis
- If given to healthy person, hematocrite may rise to levels that place intolerable strain on the heart!!! BAD NEWS BEARS!
Where is EPO made and released? What causes this to happen?
Released by the kidney in response to reduced tissue oxygenation
Why don’t RBC’s have mitochondria?
Because if they did the mitochondria would steal all of the absorbed oxygen and it wouldn’t be transported to the peripheral tissues!!!!
What is pyruvate kinase deficiency? What does it look like?
- Most common enzymopathy!
- ATP generated via glycolysis dec. 50%
- ion concentration issues in RBC’s
- Cells become rigid, leads to premature RBC destruction and hemolytic anemia
- clinical presentation varies from severe hemolytic anemia in neonates to fully compensated anemia
- Tx with folic acid supplements, splenectomy
How do you get acquired methemoglobinemia?
- Ingest certain oxidants ——> Turn into papa smurf (appear cyanotic)
- Benzacaine basically turns Fe2+ into Fe 3+
- Need to treat with reducing agent (Methylene blue) which converts Fe3+ back to Fe2+
What does Glutathione do?
Protects against ROS!
Why is G6PD important? What does it do?
- It is the first step in the Pentose Phosphate Pathway converting Glucose 6 phosphate to 6 phosphogluconate.
- In this reaction NADP+ is reduced to NADPH which in turn reduces glutathione
- Glutathione needs to be in the reduced form to clean up ROS…RBC lifespan directly correlated to G6PD
