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.

Leptin Podcast + Transcript

Podcast Link: https://soundcloud.com/robert-stoddard-3/leptin-podcast


Manuscript:

Hello, I am Bob Stoddard and this is a podcast about the
hormone in your body, leptin.  Leptin is a hormone that
tells the body when it is full or had enough to eat.  This
is the opposing hormone to ghrelin; which tells the body
when it is hungry or needs to eat.  When a person has more
ghrelin and not enough leptin in their system they continue
to eat. This is a common cause of obesity. Leptin is mainly
produced in the adipocytes or fat cells. The amount of
leptin your body produces is regulated by the amount of
energy stored in the fat cells.  If the body has enough
energy stored it sends signals via the endocrine system to
the brain.  This creates a negative feedback loop that
reduces your appetite until your body needs more energy.  At
this point leptin production will continue. Leptin is water
soluble so that it can pass through the cell membrane. It
then travels to the brain. The leptin produced activates a
receptor mainly located in the hypothalamus.  When the
receptor is active, you lose appetite until the weight and
energy you gained is expended.