Question

1. 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. the patients red blood cells will shrivel up because the blood fluid is hypotonic compared to the cells.
b. the patients red blood cells will swell because the blood fluid is hypotonic compared to the cells.
c. the patients red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells.
d. the patients red blood cells will burst because the blood fluid is hypertonic compared to the cells.

1. explain your answer to #8.

Explanation:

Question 8

To solve this, we analyze osmosis: Red blood cells have solutes (like salts, proteins). Distilled water has no solutes, so the blood fluid (with distilled water) is hypotonic (lower solute concentration) compared to the cells. In a hypotonic environment, water moves into the cell (osmosis, from low to high solute). If water enters, cells swell (and may burst, but among options, "swell" is in option b). Let's check options:

• Option a: Shrivel in hypotonic? No, shrivel is in hypertonic (water out). Eliminate.
• Option b: Swell because fluid is hypotonic (water in). Correct logic.
• Option c: Shrivel in hypertonic, but distilled water makes fluid hypotonic. Eliminate.
• Option d: Burst in hypertonic? No, hypertonic causes water out. Eliminate.

Osmosis is the movement of water across a semipermeable membrane (like red blood cell membrane) from an area of low solute concentration to high solute concentration. Distilled water has no solutes, so the blood plasma (after adding distilled water) has a lower solute concentration (hypotonic) than the interior of red blood cells (which has solutes like hemoglobin, ions). Thus, water moves into the red blood cells via osmosis. As water enters, the cells swell (since they are flexible and the membrane can expand until it may burst, but the key here is the initial swelling due to hypotonicity). This matches option b's reasoning: the hypotonic fluid causes water influx, leading to cell swelling.

Answer:

b. The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.

Question 9