If someone could help with this question I don’t understand would it be c
Why do solutions for intravenous injections into people with low blood volume (perhaps due to dehydration) normally contain 0.9% NaCl ?
A this is a hypotonic solution which will cause water to move into dehydrated blood cells
B this is an isotonic solution, and the water in IV fluid will follow Na+ and Cl- into the intracellular fluid compartment
C this is an isotonic solution, and Na+ and Cl- are non penetrating solutes. Na+ and Cl- will keep the water in iv fluid in the extracellular fluid compartment
D Na+ and Cl- are penetrating solutes which will get these more quickly into blood cells to increase their volume
For this question, what we're looking for is something that will increase the extracellular fluid level. That is, the question tells us that we give people 0.9% NaCl for those with low blood volume, thereby increasing their blood volume (extracellular fluid level). Knowing this, we can eliminate the other answer options as follows:
A. If it were hypotonic and water moved into the RBCs, they'd likely lyse. Also, we want to increase blood volume, not move water into RBCs.
B. Isotonic refers to the same solute concentration on either side and therefore there should be no net movement of water. Also, there should be no significant flux of \(Na^+\) or \(Cl^-\) into a cell, since they're both charged ions and hence cannot freely diffuse.
C. Yes, isotonic means no net movement of water, allowing the NaCl solution to remain the extracellular fluid.
D. Again, we don't want to increase the fluid within RBCs, and don't think they're penetrating solutes either