Components of the Blood

Components of the Blood

Learning Objectives

• By the end of this section, you will be able to do the following:

  • List the basic components of the blood.

  • Compare red and white blood cells.

  • Describe blood plasma and serum.

Overview of Blood Composition

• Blood is a term used to describe the liquid that moves through the vessels, consisting of:

  • Plasma (liquid portion): Contains water, proteins, salts, lipids, and glucose.

  • Cells: Includes red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

  • Cellular Components: Approximately 45% of blood, liquid plasma comprises 55%.

  • Extracellular Fluid: Blood constitutes 20% of a person’s extracellular fluid and 8% of total body weight.

Functions of Blood

• Blood is vital for the regulation of body systems and homeostasis.

  • Homeostasis: Stabilizes pH, temperature, osmotic pressure, and helps eliminate excess heat.

  • Nutrient Distribution: Supports growth by distributing nutrients and hormones while removing waste.

  • Protection:

  • Transports clotting factors and platelets to prevent blood loss.

  • Carries white blood cells to combat infections.