What happens to the concentration of sodium ions in the ECF if you consume a large amount of salt without consuming any water? How will this affect the osmotic pressure of the ECF? Why could this lead to an elevation in blood pressure? (Connects to Chapter 19)See answers in Appendix A.

Video transcript

Everyone. Let's take a look at this question together. Which of the following is a consequence of increased sodium ion concentration in the extracellular fluid. Is it answer choice? A decreased osmotic pressure and blood volume. Answer choice B increased osmotic pressure and blood volume. Answer choice C decreased osmotic pressure and increased blood volume or answer choice D increased osmotic pressure and decreased blood volume. Let's work this problem out together to try to figure out which of the following answer choices is the consequence of increased sodium ion concentration in the extracellular fluid. So in order to solve this question, we have to recall what we have learned about sodium ion concentration in the ex cellular fluid to determine which of the following answer choices is a consequence if that sodium ion concentration in the extracellular fluid were to be increased. And we can recall that an increase in sodium ion concentration in the extracellular fluid results in an increase in osmotic pressure. And in addition to that increase in osmotic pressure, an increase in sodium ion concentration in the extracellular fluid would also make the extracellular fluid hypotonic as there would be a greater concentration in the extracellular fluid than in the surrounding area. Yeah. And as a result of the extracellular fluid becoming hypotonic water would flow into the extracellular fluid. In order to balance the solute concentrations, which a consequence of water flowing into the extracellular fluid via osmosis, there would be an increase in blood volume due to that influx of water. So a consequence of increased sodium ion concentration in the extracellular fluid would be an increase in osmotic pressure and an increase in blood volume. Which means that answer choice B is the correct answer since we would see an increase in both osmotic pressure and blood volume. If we increased sodium ion concentration in the extracellular fluid and all other answer choices are incorrect. I hope you found this video to be helpful. Thank you and goodbye.