Which plasma protein is most important for maintaining the blood's colloid osmotic pressure?

• A. Globulin
• B. Fibrinogen
• C. Hemoglobin
• D. Albumin

Answer: (D)

Verified step by step guidance

1. Understand the concept of colloid osmotic pressure: It is the pressure exerted by plasma proteins on the capillary walls, which helps to retain water in the bloodstream and prevent it from leaking into the tissues.
2. Identify the role of plasma proteins: Plasma proteins include albumin, globulin, fibrinogen, and others, each serving different functions in the blood.
3. Recognize the function of albumin: Albumin is the most abundant plasma protein and plays a crucial role in maintaining colloid osmotic pressure due to its high concentration and ability to bind water.
4. Compare the functions of other proteins: Globulin is involved in immune responses, fibrinogen is essential for blood clotting, and hemoglobin is responsible for oxygen transport, none of which primarily maintain colloid osmotic pressure.
5. Conclude that albumin is the most important plasma protein for maintaining the blood's colloid osmotic pressure due to its abundance and water-binding capacity.