Blood is essential to life. Blood circulates through our body and delivers essential substances like oxygen and nutrients to the body’s cells. It also transports metabolic waste products away from those same cells. There is no substitute for blood. It cannot be made or manufactured. Generous blood donors are the only source of blood for patients in need of a blood transfusion. There are four basic components that comprise human blood: plasma, red blood cells, white blood cells, and platelets.
Blood brings oxygen and nutrients to all the parts of the body so they can keep working. Blood carries carbon dioxide and other waste materials to the lungs, kidneys, and digestive system to be removed from the body. Blood also fights infections and carries hormones around the body
Blood is made up of blood cells and plasma. Plasma is a yellowish fluid that has nutrients, proteins, hormones, and waste products. The different types of blood cells have different jobs. With each heartbeat, the heart pumps blood throughout our bodies, carrying oxygen to every cell. After delivering the oxygen, the blood returns to the heart. The heart then sends the blood to the lungs to pick up more oxygen. This cycle repeats over and over again.
The circulatory system is made up of blood vessels that carry blood away from and toward the heart. Two types of blood vessels carry blood throughout our bodies: Arteries carry oxygenated blood (blood that has gotten oxygen from the lungs) from the heart to the rest of the body. Blood then travels through veins back to the heart and lungs, so it can get more oxygen to send back to the body via the arteries.