Erythrocytes are Red blood cells that are at usual, without a nucleus. They have proteins in them that are called hemoglobin, which contains red iron relating to why the color of our blood is red. They are round in shape, and can be imagined as doughnuts, except without the hole in the middle. Enterocytes have two main functions. First, is to transmit its Oxygen taken in as food and fuel into the body. So you body can function on a regular basis, and second. Bring Carbon dioxide to the lungs to be exhaled. Leukocytes, also called white blood cells fight off the bacteria that enters our system on a daily basis. Part of our immune system, they also help protect against foreign agent that appears to be a threat. There are currently 5 different types of leukocytes in our body. Neutrophils, Eosinophils, Basophils, and Monocytes. Neutrophils, one that makes up the largest leukocytes in the body, are one of the first responders to bacteria trying to enter our body. Within our blood, they eliminate invaders by consuming them and can be seen as the puss in a cut being terminated. Basophils, one that makes up the smallest amount of leukocytes in the body, are responsible for the allergic reaction us humans have at times. Asthma attacks, hives, and swelling being a common example. It is how our body responds to bacteria or anything foreign of the sort trying to enter our body. Basophils make antibodies to this and help eliminate the cause. Eosinophils, whose job is to destroy bacteria and parasites, trap bacteria and kill without having to know the enemy. They help in tissue repair, and organ formation as well. Last but not least, Monocytes. Being the biggest type of leukocyte, they destroy foreign invaders that were not caught. After time, they also evolve, and change into other types of things that defend our body. They also take out dead, and non moving cells within our body. Also within our immune system we have B Cells, and T Cells. B Cells point out bacteria that enters our body, and form antibodies, inabling the bacteria to carry out its function. T Cells, also involved in this process, completely eliminate the foreign substance. Lastly, within in our blood system we also have something called platelets. Platelets, within our blood, stop blood loss from damaged vesicles. When there is basically a tear, they close tears by attaching to the wall and also change shape, enabling then to connect to one another. This forms fibrin threads to where chemicals are released.