Blood and the Body
The average person has about one to one and a half gallons of a liquid inside its body called blood. Blood is the most essential and important part of the body's circulatory system. The circulatory system is responsible for the movement of blood throughout the body through blood vessels. The heart is the pump that makes it all happen.
Blood has several ingredients found inside the body that are mixed together. Bone marrow, located inside the bones of the body, makes most of these ingredients that come together to produce blood. They include red blood cells, white blood cells, and platelets. In addition, a fourth ingredient called plasma, which is mostly water, is another important component of blood. Each of these components have a special function for the body.
Red blood cells carry oxygen throughout the body. It is the most abundant of the different cells inside the blood. A chemical called hemoglobin is carried by the red blood cells and gives blood its red color, and carries the oxygen too all parts of the body. The hemoglobin receives the oxygen each time a person breathes.
White blood cells help the body fight infections and are larger than red blood cells. They are not as abundant as red blood cells especially when a person is healthy. However, they increase in number when a person gets sick in order to fight off the illness. There are three kinds of white blood cells.
Granulocytes help heal wounds after an injury, prevent infections, and kills germs before they enter the body. Lymphocytes include B cells and T cells. B cells help produce antibodies which gets rid of germs when a person like bacteria or viruses. These cells also help prevent a person from getting the same germ in the future. T cells also battle germs by producing special chemicals to fight infections. Monocytes surround and destroy bacteria and viruses which can cause infections.
Platelets are cells that help stop the body from bleeding if it gets cut. When a person's skin is broken blood vessels are also cut. The platelets send out a chemical signal for the cut to eventually clot and stop bleeding by sticking together. The blood vessels heal during the process of clotting. Without platelets the bleeding would never stop.
Plasma is a yellowish liquid that carries hormones, nutrients, and proteins throughout the body. It is mostly made of water but the nutrients come from the chemicals in digested food. The chemicals give the body energy and other things the cells of the body need to keep it working and healthy. The hormones carried by the plasma carry messages throughout the body that gets muscles and bones to grow. The proteins in the body work with the platelets to help with clotting. Plasma also carries away cell waste.
Finally, even though everybody's blood is red, it is not all the same. There are eight different blood types which are described using the letters A, B, and O. The letters represent specific proteins found on the red blood cells, and not everyone has the same proteins. A person's blood type is also either positive or negative, which tells whether the body has a special protein called 'Rh'.
In summary, blood is important for the body, which contains four major components, red and white blood cells, platelets, and plasma. The blood inside the body helps keep a person well, which is why it is important to eat healthy so a person can get the vitamins and minerals it needs.