Jan. 16, 2025 | Blood is a specialized body fluid. It has four main components, plasma, red blood cells, white blood cells, and platelets. Blood has many functions, including transporting oxygen and nutrients to the lungs and tissues and bringing waste products to the kidneys and liver, which filter and clean the blood. The blood that runs through the veins, arteries, and capillaries is known as whole blood. About seven to eight percent of your total body weight is blood. An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about nine pints. There are four blood types, A, B, AB, or O. Also, blood is either Rh-positive or Rh-negative. So, if you have type A blood, it’s either A positive or A negative. Which type you are is important if you need a blood transfusion. And your Rh factor could be important if you become pregnant as an incompatibility between your type and the baby’s could create problems.

Jan. 16, 2025 | The liquid component of blood is called plasma, a mixture of water, sugar, fat, protein, and salts. The main job of the plasma is to transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones, and proteins that help maintain the body’s fluid balance. Plasma is also responsible for regulating your body temperature by absorbing and releasing heat and providing defense against bacterial, viral, fungal and parasitic infections. It’s a light yellow color and resembles the color of straw. Although plasma makes up more than half of your blood’s total volume, the color of red blood cells dominates the color of your whole blood. Plasma is essential for your body to function and serves as the liquid that holds your red and white blood cells and platelets together. Plasma disorders are rare, but your donation of plasma can help others live healthy lives.

Jan. 16, 2025 | Red cells are the most abundant cell in the blood, accounting for about 40 to 45 percent of its volume. Red blood cells start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream. Unlike many other cells, red blood cells have no nucleus and can easily change shape, helping them fit through the various blood vessels in your body. However, while the lack of a nucleus makes a red blood cell more flexible, it also limits the life of the cell as it travels through the smallest blood vessels, damaging the cell’s membranes and depleting its energy supplies. Red cells contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled. The percentage of whole blood volume that is made up of red blood cells is called the hematocrit, a common measure of red cell levels.

Jan. 16, 2025 | White blood cells protect your body against infection. As your white blood cells travel through your bloodstream and tissues, they locate the site of an infection and act as a general to notify other white cells of their location to help defend your body from an attack of an unknown organism. Once your white blood cell army arrives, they fight the invader by producing antibody proteins to attach to the organism and destroy it. If you have a low white blood cell count, you are likely to get infections, a condition called leukopenia. If your white blood cell count is too high, you may have an infection or a medical condition like leukemia, lymphoma or an immune disorder. It is normal for you to produce nearly 100 billion white blood cells each day. After completing a blood draw, a test counts your white blood cells, which equals number of cells per microliter of blood. The normal white blood cell count ranges between 4,000 and 11,000 cells per microliter.

Jan. 16, 2025 | Platelets are tiny blood cells that help your body form clots to stop bleeding. If one of your blood vessels gets damaged, it sends out signals to the platelets. The platelets then rush to the site of damage and form a clot to fix the damage. The process of spreading across the surface of a damaged blood vessel to stop bleeding is called adhesion. This is because when platelets get to the site of the injury, they grow sticky tentacles that help them adhere to one another. They also send out chemical signals to attract more platelets. The additional platelets pile onto the clot in a process called aggregation. It’s important that you have enough platelets but not too many of them. Too few platelets can put you at risk of losing too much blood if you’re injured. Too many platelets may increase your risk of blood clots. The right number of platelets can prevent blood loss during injury without putting you at risk of harmful clots that can restrict blood flow.