The Human Circulatory System - Biology Chapter 8, Class 10 ICSE

The circulatory system relies on three main fluids to transport nutrients and remove waste inside our bodies, which are blood, tissue fluid, and lymph. Blood consists of a liquid part called plasma and three types of cells. Red blood cells carry oxygen using a pigment called haemoglobin, white blood cells defend the body against infections by engulfing germs and producing antibodies, and platelets help form clots at wounds to prevent excessive bleeding. The human heart acts as the central pumping station and consists of four chambers equipped with valves that keep blood flowing in a single direction. We have a double circulation system, meaning blood passes through the heart twice during one complete cycle. The pulmonary circulation pumps deoxygenated blood to the lungs to receive oxygen, while the systemic circulation distributes this oxygenated blood to all other body tissues before returning it to the heart. Three main types of blood vessels form the pathways for this continuous flow. Arteries carry blood away from the heart under high pressure, veins bring blood back to the heart using valves to prevent backflow, and extremely thin capillaries connect them to allow the actual exchange of materials with surrounding cells. Working alongside this is the lymphatic system, which includes the spleen and lymph nodes, helping to drain excess tissue fluid, absorb fats, and provide additional defense against disease. #dohrao #dohraoicseclass10 #icseclass10 #icseclass10biology