Question

Normal saline, which is 0.9% NaCl, is isotonic with body cells and fluids, and can be safely used intravenously. If distilled water is accidentally used instead of normal saline, are the cells surrounded by a hypotonic, hypertonic, or isotonic environment? a) Hypotonic b) Hypertonic c) Isotonic d) Osmotic.

Answer 1

If distilled water is used instead of normal saline, the cells are surrounded by a hypotonic environment, leading to water entering the cells, potentially causing them to swell and burst. Normal saline is isotonic and therefore should be used to avoid cellular damage. The correct option is A.

Step-by-step explanation:

If distilled water is accidentally used instead of normal saline, the cells are surrounded by a hypotonic environment. This is because distilled water lacks solutes and has a lower osmolarity compared to the cytoplasm of body cells. Therefore, water will enter the cells to equalize the solute concentration, which could cause the cells to swell and potentially burst, a phenomenon known as lysis. Normal saline, which is 0.9% NaCl, is used intravenously because it is isotonic with body cells and fluids, meaning it has the same osmolarity, preventing the net movement of water into or out of the cells.

When dehydrated patients require intravenous fluids, isotonic solutions like 0.9% NaCl or 5% glucose are used because they match the solute concentration of body fluids, maintaining cellular integrity.

Hypotonic solutions, on the other hand, would lead to an influx of water into cells, while hypertonic solutions would cause cells to shrink due to water leaving the cell. It's crucial for medical professionals to use an isotonic solution to avoid causing harm to the cells.