Plasma contributes approximately _____ percent of the volume of whole blood, and water accounts for _____ percent of the plasma volume.
(a) 55, 92
(b) 25, 55
(c) 92, 55
(d) 35, 72

Verified step by step guidance

1. Step 1: Understand the components of blood. Whole blood consists of plasma and formed elements (like red blood cells, white blood cells, and platelets). Plasma is the liquid portion of blood.
2. Step 2: Recall that plasma makes up a significant portion of whole blood volume, typically more than half. This percentage is commonly around 55%.
3. Step 3: Recognize that plasma itself is mostly water, with other components like proteins, electrolytes, and nutrients dissolved in it. The water content of plasma is usually very high, close to 90% or more.
4. Step 4: Match the typical values for plasma volume percentage of whole blood and water percentage of plasma volume to the given options. The correct pair should reflect approximately 55% plasma in whole blood and about 92% water in plasma.
5. Step 5: Select the option that best fits these known physiological values.

Key Concepts

Composition of Whole Blood

Whole blood consists of cellular components (red cells, white cells, platelets) suspended in plasma. Plasma is the liquid portion, making up about 55% of the total blood volume, which is essential for transporting nutrients, hormones, and waste products.

Plasma Composition

Plasma is primarily composed of water, which accounts for approximately 90-92% of its volume. The remaining plasma consists of proteins, electrolytes, nutrients, and waste products, making water the major solvent in blood plasma.

Volume Percentages in Blood Components

Understanding the percentage volumes of blood components helps in clinical assessments. Plasma volume is about 55% of whole blood, and within plasma, water constitutes roughly 92%, which is critical for maintaining blood fluidity and transport functions.