A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water-equal to the volume of blood lost-is transferred directly into one of his veins. What will be the most probable result of this transfusion?
A) It will have no unfavorable effect as long as the water is free of viruses and bacteria.
B) The patient's red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells.
C) The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells.
D) The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.
E) The patient's red blood cells will burst because the blood fluid has become hypertonic compared to the cells.

Question

Quizplus · Accepted Answer

The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells. When distilled water is added to the bloodstream, it dilutes the blood plasma, making it hypotonic relative to the red blood cells. This causes water to move into the cells by osmosis, leading to swelling and potentially bursting (hemolysis).

A Patient Has Had a Serious Accident and Lost a Lot