Blood is primarily used to transport cells and different substances around the body. It can be divided into 4 categories of components: the blood plasma, trombocytes (platelets), leukocutes (white blood cells) and erythrocytes (red blood cells). The blood plasma is a mixture of water as well as salts and different organic molecules such as sugars and lipids and is used to transport nutrients and other necessary materials to cells across the body as well as get rid of the waste from those cells so that it can be removed. The other 3 groups are cell types, each having a different function within the blood stream. Firstly, red blood cells are responsible for carrying oxygen to cells (those are referred to as being in an oxygenated state) as well as carbon dioxide form cells (deoxygenated state). Red blood cells do not have a nucleus in order to fit larger quantities of oxygen and carbon dioxide. White blood cells are responsible for targeting foreign substances and organisms within the body and removing them. They can be divided into different categories based on how they function and use different methods to eliminate threats, from chemical reactions to devouring the foreign elements. Lastly, platelets, coupled with coagulation factors, are responsible for blood clotting. They are used to seal any damage done to the veins and arteries so that blood is not lost and the injury can be then repaired.