AAMC FL Practice Exam

What effect does malnutrition generally have on osmotic pressure in the blood?

1. Increase in osmotic pressure

2. No change in osmotic pressure

3. Decrease in osmotic pressure

4. Stabilization of osmotic pressure

The correct answer is: Decrease in osmotic pressure

Malnutrition often leads to a decrease in osmotic pressure in the blood primarily due to a reduction in the concentration of proteins, particularly albumin, which is a critical component of the blood plasma. Albumin plays a significant role in maintaining oncotic pressure, which is a subset of osmotic pressure that specifically pertains to the pressure exerted by proteins in the blood plasma. When a person is malnourished, their intake of essential nutrients, including proteins, is inadequate. This can result in lower levels of albumin and other plasma proteins, leading to reduced oncotic pressure. As a consequence, fluids may escape from the bloodstream into surrounding tissues, contributing to conditions such as edema. Understanding the relationship between nutrition and osmotic pressure is vital, as it underscores the importance of adequate protein intake for maintaining fluid balance within the vascular system.