Cardiovascular System Overview

Introduction to the Cardiovascular System

• The cardiovascular system comprises the heart, blood vessels, and blood.
• Its primary function is transporting oxygen-rich nutrients to all body parts and returning deoxygenated blood to the lungs.
• The main components of the cardiovascular system are blood, the heart, and blood vessels.

Blood

• Blood consists of blood cells (red blood cells, white blood cells, and platelets) and plasma (the fluid portion).
• Red blood cells (RBCs) carry oxygen and carbon dioxide.
• White blood cells (WBCs) are part of the immune system.
• Platelets are involved in blood clotting.
• Plasma is largely composed of water, proteins, ions, nutrients, and wastes.

Heart

• The heart is a four-chambered, hollow muscular organ roughly fist-sized.
• It is located superior to the diaphragm, left of the midline, and anterior to the vertebral column, behind the sternum.
• The heart has four chambers: two atria and two ventricles.
• The right atrium receives deoxygenated blood, while the left atrium receives oxygenated blood.
• The right ventricle pumps blood to the lungs, and the left ventricle pumps blood to the rest of the body.

Heart Valves

• Heart valves ensure unidirectional blood flow.
• Atrioventricular (AV) valves (tricuspid and mitral/bicuspid) are between the atria and ventricles, preventing backflow into the atria during ventricular contraction.
• Semilunar valves (pulmonary and aortic) are at the bases of the large vessels leaving the ventricles, preventing backflow into the ventricles during ventricular relaxation.

Pathway of Blood Through the Heart and Lungs

• Deoxygenated blood enters the right atrium, then through the tricuspid valve to the right ventricle.
• The right ventricle pumps the blood to the lungs via the pulmonary arteries.
• Oxygenated blood returns from the lungs via the pulmonary veins to the left atrium.
• Then through the mitral valve to the left ventricle.
• The left ventricle pumps blood through the aortic valve to the aorta, distribution to the rest of the body.

Pulmonary Circulation

• Pulmonary circulation is the portion of the cardiovascular system responsible for transporting deoxygenated blood away from the heart to the lungs and returning oxygenated blood back to the heart.
• This is where oxygen enters the blood, and carbon dioxide leaves the blood.

Systemic Circulation

• Systemic circulation is the portion of the cardiovascular system transporting oxygenated blood away from the heart to the rest of the body and returning deoxygenated blood to the heart.
• It's a much longer process than pulmonary circulation, as it involves transporting blood to every part of the body.

Coronary Circulation

• Coronary circulation is the circulation of blood through the arteries and veins supplying the heart muscle.
• It's the functional blood supply to the heart muscle itself.

Blood Vessels

• Blood vessels form a closed network of tubes.
• Arteries carry oxygenated blood away from the heart.
• Capillaries are the smallest blood vessels for nutrient and gas exchange.
• Veins carry deoxygenated blood back to the heart.

Blood Vessel Structure (General)

• Blood vessels have three layers: tunica intima, tunica media, and tunica adventitia.

Test your knowledge on the fundamental aspects of the cardiovascular system. This quiz covers the functions of heart valves, circulation types, and blood composition. Dive into the details of how blood flows through the heart and the role of different components in the circulatory system.