Immune System Quiz

This blog post will be discussing how the Immune system works and why it is very important to humans for survival.  The four questions that will be answered the most in this post are:

1. Provides an immediate nonspecific immune response
2. Activates T and B cells in response to an infection
3. Responds to a later exposure to the same infectious agent
4. Distinguishes self from non-self

So, firstly, our immune system is very important because it is constantly working to protect our body from harmful bacteria.  It does this mainly through a nonspecific immune response.  This is the first line of defense our body has against foreign invaders.  Unlike the adaptive immune system, after warding off an invader the host will not gain immunity or adapt to fight this invader.  This type of immune systems is in plants, but we as vertebrates, have an adaptive immune system as well.  This innate immune system is triggered when there is an infection or foreign bacteria in the body.  In these situation it triggers a chemical reaction telling your body to send white blood cells to this location.  Next, we must look at how and why T and B cells are sent to infected areas and what their purpose is.  B cells produce antibodies that can eliminate bacteria and other dangerous materials.  T cells hunt viruses that have invaded our body.  Both of these cells are activated when their respective purposes are needed.  This activation is brought on by a process initiated with proteins in the circulatory system.  They identify and "paint a target" on foreign invaders.  These targets bring phagocytes that "eat" bacteria until they die.  Often, phagocytes create antigens that attach to receptors to T and B cells in the lymphatic system.  Once these receptors are filled the cells go out to fight the infection or invasion where the bacteria or virus is at.

This whole process helps later infections using a memory in the T and B cells that remembers what the bacteria or invaders were.  This means that if you were to get the same bacteria in your system again at some point, your body would be faster to respond and neutralize the problem.  An important question to ask through all of these processes is, how does our body know what cells are foreign?  Well, quite simply put, your body recognizes it's own cells and your bodies own cells unless mutated or harmful will not set off antibodies.  This is the reason blood types are important and there must be matches for organ transplants.  Your immune system will always attack what is foreign.  Your body can only judge what is foreign however, if it knows what is 'self'.  This happens when you are in the womb.  Over time as you develop in the womb, your body learns what cells to accept.  This is why your antibodies do not destroy cells all the time.  This is a basic overview of how your immune system works.  It is vital in human survival to have a resilient immune system.  Not only does it save our lives from millions of bacteria, it creates cells that know how to handle much more dangerous invaders very quickly.