Biology – 8.2 Transport in humans | e-Consult

The structure of the heart is highly adapted to facilitate efficient blood circulation. Its key features include four chambers (two atria and two ventricles) and a system of valves.

Chambers:

• Right Atrium: Receives deoxygenated blood from the body via the superior and inferior vena cava.
• Right Ventricle: Receives deoxygenated blood from the right atrium and pumps it to the lungs via the pulmonary artery.
• Left Atrium: Receives oxygenated blood from the lungs via the pulmonary veins.
• Left Ventricle: Receives oxygenated blood from the left atrium and pumps it to the rest of the body via the aorta. This is the most muscular chamber.

Valves:

• Tricuspid Valve: Located between the right atrium and right ventricle. It prevents backflow of blood from the right ventricle into the right atrium.
• Pulmonary Valve: Located between the right ventricle and the pulmonary artery. It prevents backflow of blood from the pulmonary artery into the right ventricle.
• Mitral Valve (Bicuspid Valve): Located between the left atrium and left ventricle. It prevents backflow of blood from the left ventricle into the left atrium.
• Aortic Valve: Located between the left ventricle and the aorta. It prevents backflow of blood from the aorta into the left ventricle.

Adaptations for efficient circulation:

• Four Chambers: Separation of oxygenated and deoxygenated blood prevents mixing, ensuring efficient oxygen delivery to the body.
• Thick Walls (especially Left Ventricle): The left ventricle has significantly thicker walls than the other chambers, reflecting the higher pressure required to pump blood to the entire body.
• Valves: The valves ensure unidirectional blood flow, preventing backflow and maximizing efficiency.