With so many diseases and bacteria running amok in the world, how do we tend to stay fairly healthy? Luckily, our bodies are equipped with a defense system to wipe out threats before they become an issue. The lymphatic system and its series of vessels, similar to veins, work to eradicate invaders that are in the bloodstream, tissues, and cells of our bodies. In addition, this system works to maintain fluid levels, absorb fat in the digestive tract, and remove waste products.
Lymphocytes
Your body produces white blood cells, also called leukocytes, as your private army. Each type of leukocyte responds to a particular type of threat. The lymphatic system aids in the body’s defense by producing lymphocytes: B cells, T cells, and NK cells. All three lymphocytes originate from the spongy tissue inside of bones called bone marrow. The migration of the cells following production allows for their specialization.
- B cells remain in the bone marrow and mature to become factories for antibodies. An antibody is a protein produced by the immune system for fighting invaders, called antigens. Each antibody matches an antigen, like a lock and key, to destroy it.
- T cells migrate from the bone marrow to the thymus. Once there, they mature into cancer killing machines. T cells monitor foreign substances or mutated cells to prevent the spread of a virus or cancer to other cells.
- NK cells are known as natural killers that go out and attack cancer or virus ridden cells, similar to T cells.
Parts of the System
The lymphatic system displaces excess fluid from cells and tissues (lymph) using several branches of tubes (lymphatic vessels) that span the entire body. Along these vessels are several “pit stops” called lymph nodes. Each lymph node houses numerous immune cells that filter out infected or cancerous cells from the lymph. Once lymph moves past the nodes, it eventually arrives at one of the collecting ducts. Here, the lymph is dumped back into the bloodstream to increase blood volume and the number of white blood cells. The organs of this system are summarized in the graphic below:
Lymph becomes mobile through muscular contraction and changes in pressure surrounding the lymphatic vessels. Essentially, moving the body leads to movement in the system as well. The movement of lymph begins when lymph capillaries (very thin lymph vessels) in the tissues absorb the fluid that the cells do not. Once in the capillary, the lymph is pushed to lymph nodes to be filtered and sent on to the next until it reaches a collecting duct. This process, as well as an overview of the system, are shown in the diagram below:
Want to know more about the human body? Check out this article!
