The immune system is responsible for your health and well being. It keeps you alive and feeling good, and it also causes symptoms of colds, such as a runny nose, fever, and swelling. These are all signs of your body trying to maintain homeostasis. There are also multiple types of tissue in the immune system. First, epithelial tissue is important because the skin is the first line of defense in the immune system. Also, there is connective tissue, which connects all of the different organs in the immune system. Finally, there is nervous tissue. The brain controls all of the immune system. The nervous tissue links the organs to the nervous system.
The immune system is constantly fighting external pathogens, or bacteria that cause disease. To go about this, there is a distinct process that goes on. First, the pathogen has to get into the body. Then, the bacteria grow and multiply under the radar. Third, the macrophage cells take notice. They eat and kill the bacteria, call for help, and cause inflammation. Neutrophils come from the blood. They also kill bacteria. Dendritic cells are activated by the macrophages. They evaluate what type of infection there is, and then proceed to call in helped T-cells. Next, the Helper T cells go fight, make Memory Helper T cells, and activate B cells. B cells produce antibodies to fight the pathogens. The antibodies allow macrophagesg and Killer T Cells to easily destroy pathogens.
The immune system does many things, but it also interacts with many other systems. First, the skin is the first line of defense in the immune system, so the integumentary system is very important. Second, T Cells are produced and stored in lymph nodes, so the lymphatic system is essential. The immune system also works with the circulatory system in order to prevent infection.