Anatomy & Physiology Circulatory #11

Question

Which substance accounts for 90% of plasma?

Answers

  1. Water
    • Rationale:

      Water accounts for 90% of the volume of plasma.

  2. Oxygen
    • Rationale:

      While plasma albumin allows oxygen to enter the cells of the body, oxygen does not account for 90% of the plasma’s volume.

  3. Nutrients
    • Rationale:

      While plasma albumin allows nutrients to enter the cells of the body, these nutrients do not account for 90% of the plasma’s volume.

  4. Electrolytes
    • Rationale:

      While plasma albumin allows electrolytes to enter the cells of the body, these electrolytes do not account for 90% of the plasma’s volume.

Overview

Plasma is defined as the colorless fluid part of blood or lymph fluid in which corpuscles (i.e., fat globules) are suspended.

Explanation

Learning Outcomes

Over 50% of the volume of blood is plasma and over 90% of plasma is water. The other main component of plasma is plasma albumin. This is a protein that enables and controls the osmotic pressure of the blood thus enabling electrolytes, hormones, oxygen, and nutrients to enter the cells and tissues of the body. In addition, plasma albumin also enables the elimination of wastes from the cells and tissues of the body.

Test Taking Tip

Consider the substance that is contained in large amounts throughout the body to answer this question correctly.

Video Rationale