Cardiovascular System Overview

Cardiovascular System

• The cardiovascular system is comprised of the heart and the circulatory system of blood vessels.
• The heart is composed of four chambers: two atria (left and right) and two ventricles (left and right).
• Blood enters the heart through the upper chambers of the left and right atria and exits via the left and right ventricles.

Functions of the Cardiovascular System

• The cardiovascular system has three major functions: transportation of materials, protection from pathogens, and regulation of the body's homeostasis.
• The heart acts as a two-way pump, with the left and right sides operating as separate pumps.

The Heart

• The heart is a four-chambered "double pump" with each side separated by a muscular wall of tissue known as the septum of the heart.
• The right side of the heart receives deoxygenated blood from the systemic veins and pumps it to the lungs for oxygenation.
• The left side of the heart receives oxygenated blood from the lungs and pumps it through the systemic arteries to the tissues of the body.

Circulatory Loops

• There are two primary circulatory loops in the human body: the pulmonary circulation loop and the systemic circulation loop.
• The pulmonary circulation loop involves the right side of the heart, lungs, and pulmonary veins.
• The systemic circulation loop involves the left side of the heart, systemic arteries, and systemic veins.

Cardiovascular System Components

• The cardiovascular system includes the heart, blood vessels, and blood.
• The heart is a muscular pump that forces blood around the body.
• The blood vessels include arteries, veins, and capillaries.
• Arteries carry blood away from the heart, while veins bring blood back to the heart.
• Capillaries are tiny vessels that branch off from arteries to deliver blood to all body tissues.

Heart Valves

• Heart valves normally allow blood flow in only one direction through the heart.
• The heart has four chambers: two upper, thin-walled atria, and two lower, thick-walled ventricles.
• The two atrioventricular (AV) valves are the mitral valve and the tricuspid valve.
• The two semilunar (SL) valves are the aortic valve and the pulmonary valve.

Function of the Heart

• Blood lacking oxygen returns from the body and enters the right atrium via the inferior vena cava and superior vena cava veins.
• Blood flows through the tricuspid valve and enters the right ventricle, then pumps blood through the pulmonary valve and out of the heart via the main pulmonary artery.
• The blood then flows through the left and right pulmonary arteries into the lungs, where it picks up oxygen and releases carbon dioxide.
• The oxygen-rich blood returns to the heart and flows into the left atrium via four pulmonary veins, then flows through the mitral valve and enters the left ventricle.

Learn about the structure and function of the cardiovascular system, including the heart's four chambers and the circulation of blood through the body. Explore how blood is pumped through the aortic valve into the aorta and distributed to the rest of the body.