Human Body: Circulatory System

The circulatory system’s primary role in the human body is transporting substances like gases (oxygen and carbon dioxide), nutrients, hormones, and waste products across various parts of the body.
This system consists of three major parts: the heart, blood vessels, and blood.
The heart, which acts as a pumping station, has four chambers - the left and right atria and the left and right ventricles.
The heart’s pumping action maintains pressure, propelling blood throughout the body. This pump is divided into two halves. The right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the rest of the body.
There are three types of blood vessels: arteries, veins, and capillaries.
Arteries carry oxygenated blood away from the heart (except the pulmonary artery), while veins transport deoxygenated blood towards the heart (except the pulmonary vein).
Capillaries, being small and thin, allow for exchange of substances between the blood and the body cells.
Red blood cells contain haemoglobin, a protein that binds to oxygen in the lungs and transports it to the body’s cells. Haemoglobin then picks up carbon dioxide, a waste product, to be expelled from the lungs.
White blood cells play a vital role in the body’s immune response, helping combat infections and diseases.
Platelets help in the clotting of blood, preventing excessive blood loss during injury.
Blood plasma, a yellowish liquid component, carries cells, proteins, hormones, nutrients, and waste products.
The circulatory system also helps regulate body temperature. When you’re hot, blood vessels in the skin dilate to allow more blood flow to the skin’s surface, promoting heat loss. When you’re cold, these blood vessels constrict to keep warm blood deeper in your body, conserving heat.
The circulatory system and respiratory system work closely together. Oxygen enters the body via the respiratory system, then the oxygenated blood is circulated around the body by the circulatory system.