Components of the Circulatory System

This guide provides an overview of the circulatory system, focusing on the composition of blood, the structure of the heart, and the role of blood vessels in circulation.

Blood Composition

Blood comprises four main components:

• Red blood cells (RBCs)
• White blood cells (WBCs)
• Platelets
• Plasma

Anatomy of the Heart

The heart, located slightly to the left center of the chest and about the size of a fist, has four chambers:

• Two upper chambers called the atria
• Two lower chambers called the ventricles

Heart Valves

The heart contains several types of valves:

• Atrial-ventricular valves between the atria and ventricles
• Semilunar valves and pulmonary valves

Heart Circulation Model

The heart circulates blood in two main pathways:

• The right side receives deoxygenated blood from the body and sends it to the lungs via the pulmonary artery.
• The left side receives oxygenated blood from the lungs via the pulmonary vein and distributes it throughout the body via the aorta.