What is the Composition and Function of Blood in the Human Body?

Blood is an essential component of the human body. It is responsible for the transportation of oxygen and nutrients all throughout the body. Additionally, it helps the body remain homeostatic, meaning that the body remains balanced as it needs to be. It also helps a person's body control its temperature and protect against potential threats and pathogens. Finally, if a person somehow injures himself or herself, blood has the ability to form a clot to prevent a person from bleeding out too much.

Blood is made from two main things, plasma and elements. The plasma is blood the liquid that allows it to flow freely through the various vessels that it travels through. It is made mostly from water, but also contains a small amount of proteins and other molecules. The elements are the important things in the blood that serve various purposed. Some of these elements are white blood cells, red blood cells, and blood platelets.

Red blood cells are primarily responsible for transporting oxygen throughout the body. What makes them different from other cells is that they do not develop a nucleus. The body is constantly producing red blood cells, but they typically only live for roughly four months. Additionally, they contain hemoglobin, which is a combination of oxygen and iron.

White blood cells, unlike red blood cells, do contain a nucleus. However, they do not contain hemoglobin like red blood cells do. They are usually larger in shape and their main function is to fight of diseases or other pathogens that invade the body. There are five different types that all serve different purposes.

Blood platelets are pieces of megakaryocytes that are from red bone marrow. There main function is to help the blood coagulate, or clot, when necessary. There are a large number of factors that help blood clot. The body produces these various factors throughout the body and then add them too the blood. For example, fibrinogen is a protein that is made by the liver so that it can be added to the blood to assist in the clotting process. Without these factors, blood would never clot and would lead to many serious issues.

Source:

Benitz, Bill. Lecture: Human Biology. November 9, 2009