Question

When the kidney goes into failure, one of the signs that doctors will see is that red blood cells will crenate (shrivel up). Why does this happen in kidney failure? What process is occurring to the blood cells?

a) Hypotonicity causes excessive water loss from the cells.
b) Hypertonicity results in water influx into the cells.
c) Increased urea concentration leads to osmotic stress on the cells.
d) Decreased glucose levels affect cell membrane integrity.

Answer 1

In kidney failure, red blood cells crenate due to a hypertonic blood condition created by increased urea concentration, which causes water to exit the cells, leading to crenation.

Step-by-step explanation:

When the kidney goes into failure, one of the signs is that red blood cells will crenate. This condition indicates that the blood is hypertonic, which means there is a higher concentration of solutes outside the cells compared to inside. As a result, water moves out of the cells to balance the solute concentration, causing the cells to shrivel up. This shift in osmotic balance can be attributed to an increased urea concentration in the blood, which is common in kidney failure as the kidneys are less able to excrete urea. Therefore, the correct answer to what is occurring to the blood cells is that increased urea concentration leads to osmotic stress on the cells, option c).