Part A Will a red blood cell undergo crenation, hemolysis, or no change in each of the following solutions? Drag the appropriate items to their respective bine. Reset Help 2 % (m) glucose 0.9% (mv) NaCl 0.5% (m) Naci 9 % (mv) NaCl Crenation Hemolysis No change Submit Request Anas Provide Feedback
The Correct Answer and Explanation is:
Correct Classification:
- Crenation:
- 9% (m/v) NaCl
- Hemolysis:
- 0.5% (m/v) NaCl
- 2% (m/v) glucose
- No change:
- 0.9% (m/v) NaCl
Explanation
Red blood cells (RBCs) are highly sensitive to the osmolarity of their surrounding environment. The effects of various solutions on RBCs—whether they undergo crenation, hemolysis, or remain unchanged—depend on the tonicity of the solution relative to the internal environment of the cell.
1. Isotonic Solution (0.9% NaCl):
This is the standard isotonic saline concentration, which closely matches the osmolarity of human blood. When RBCs are placed in a 0.9% NaCl solution, there is no net movement of water across the cell membrane, so the cells maintain their normal shape and volume. Hence, no change occurs.
2. Hypertonic Solution (9% NaCl):
This solution has a much higher concentration of solutes compared to the inside of the RBCs. Water moves out of the cells to balance the concentration, leading to cell shrinkage. This process is known as crenation. Crenated cells appear shriveled under a microscope.
3. Hypotonic Solutions (0.5% NaCl and 2% glucose):
These solutions have lower osmolarity than the fluid inside the RBCs. Water enters the cells due to osmosis, causing them to swell. If too much water enters, the cells may burst, a process called hemolysis. Although 2% glucose is non-ionic, it is still hypotonic relative to the RBC’s interior, leading to water influx and hemolysis.
Understanding this physiological concept is crucial in medicine. For example, administering incorrect IV fluids can damage red blood cells. Isotonic solutions are typically used to avoid damaging RBCs, while hypertonic or hypotonic solutions are used only when clinically justified.
