The Immune system differs from all the other Systems of our human body. This system is not a specific tissue organ system. Instead, it involves many different tissue groups, organ systems, and specialized but widely distributed defense cells.
Together, this alliance of extraordinary substances joins forces to perform all of the defense functions that your body depends upon to keep you alive and free from infections.
What is your first line of defense in the never-ending battle?
Your body’s primary line of defense against infections is your innate or nonspecific defense system. Like your average frontline soldier, your Immune System is prepared to engage with anyone suspicious immediately. It primarily includes stuff we were born with. These are:
- the external barricades of your skin
- mucous membranes
- internal defenses such as phagocytes
- antimicrobial proteins,
- other attack cells.
However, some enemies must be fought with special forces. Here, your body can employ your adaptive or specific defense system.
Let us see how your Immune System uses an arsenal of chemical and physical barriers, fever, and killer cells to keep you healthy.
Sometimes the symptoms we associate with ill health are the signs that we are healing.
Innate defenses
Your body can defend itself from infections in a very sophisticated manner. Your skin does a fantastic job of keeping out all malevolent microorganisms, just like a wall around a fortress. The tough, keratinized epithelial membrane keeps many bacteria at bay until it gets torn open or busted up too much.
Your mucous membranes also serve as a physical barrier. They line all cavities that open up into the outside world, including the respiratory, digestive, urinary, and reproductive tracts. Not only does your skin and mucous provide simple physical protection, but they also pack some serious chemical weaponry. What happens when you walk face-first into your coworker’s sneeze cloud? You don’t need to worry because your nasal passages can whip up a tissue box worth of sticky mucus to help trap viruses before they enter your lungs.
You’ve also got bacteria-fighting enzymes in your saliva and your lacrimal eye fluid. In addition, you have peptides called defensins in your skin and membranes that help keep bacteria and fungi from setting up around scraped or inflamed skin.
When you cut yourself or have your first line of defense breached, it’s time to call on your innate internal defenses. This is where your body starts pulling up strategic maneuvers such as:
- firing up a fever
- releasing chemical signals
- causing inflammation
- other defensive tactics that help identify and attack infectious invaders.
How do viruses work?
Viruses need a host to do their job. They are not something that can replicate on their own. Instead, viruses work by latching onto specific cells in the host body. First, they inject their genetic material into the ”vulnerable cells” to infect them. Then a cascade of events is triggered, resulting in the merger of the virus with the cell. This merger allows the cell to release its genetic material and hijack the cell’s internal machinery.
Once this happens, the human cell is turned into a factory that churns out new virus cells. The cell then does the same things that the virus wants it to do.
What happens when your first line of defense is breached
Let’s say you slip and scrape your knees. Your outer fortress has been breached, and your pathogens are just flooding in. Now your body wants to contain the spread of pathogens, clean up the mess and get healing as quickly as possible. So, it cues up your inflammatory response. This is an internal fire alarm. The only disparity is that it uses chemicals instead of sirens to get the message across. Instead of smoke and fire, you sense redness, swelling, heat, and pain. They are all signs of healing. Fever increases your body’s temperature and races up the cells’ metabolic rates so that they can repair themselves faster.
Fortunately, the human immune system has several different ways to identify and eradicate virally infected cells. Let us see how your immune system works in response to viral infections.
Some of the first defensive cells on the scene are your phagocytes. Their name means “to eat,” and they indiscriminately chase intruders and gobble them up. They come in a few different varieties:
First, you’ve got the neutrophils which are the most abundant type of white blood cells. They self-destruct after devouring a pathogen. And you’ve probably seen piles of their dead bodies because that is what pus is made of.
The bigger, tougher phagocytes are the macrophages. They are derived from monocyte white blood cells that have moved out of the bloodstream to occupy tissues. So, when you happen to cut your finger, your macrophages see a new bacterium coming along. They snare it using cytoplasmic extensions, reel in it completely, engulfs it, essentially digests it, and spits the rest out.
Cytotoxic t cells
Your immune system is a highly complex intelligent system. One of the weapons at its disposal is cytotoxic t cells. Cytotoxic t cells are circulating in your system and are sort of like a police car on patrol. For example, suppose it notices that a virus has blocked a receptor on a cell. In that case, it releases these cytotoxic factors to prevent grand theft.
So, cytotoxic t cells are one of the weapons constantly scanning and patrolling via the Immune system.
Natural killer cells (NK cells)
Viruses are very crafty. They sometimes try to hide out, causing a reduction in the active receptor sites on the cell. The natural killer cells function like the FBI, sniffing out clues and seeing that the virus is trying to hide. When they discover that a particular cell is not working usually or is not looking like the rest of the cells, it puts a case together. It then goes after the virally infected cells by releasing toxic substances that destroy the infected cells.
Interferons
Another immunological weapon that we have is interferons. Interferons are a group of signaling proteins made and released by your host cells in response to the presence of viruses. They are named interferons because of their ability to interfere with viral replication and protect nearby cells from viral infections. These interferons are like undercover agents keeping an eye out, sending signals, and interfering with any wrongdoing.
Sooner or later, a threat will come that is stronger than what the first responders can handle. That’s when it is time for the adaptive or acquired immune system to step in. Your innate immune system takes its zero-tolerance policy very seriously, trying to toast any foreign microbe that it encounters. However, your adaptive immune system does things differently.
It must be expressly introduced to a specific pathogen and recognize it as a threat before it will attack. As the name suggests, you are not born with a working adaptive immune system. It is slow to act because it takes time to shake hands with so many pathogens and get to know them.
Once the immune system remembers a specific pathogen, it never forgets them. Thus, the ability to recognize particular pathogens is the crucial difference between adaptive and innate defenses.
Humoral Immunity
One more weapon that our incredible Immune system has is known as B cells. B cells are responsible for what is known as humoral immunity. Humour Immunity produces proteins called antibodies that quote remember an infection and stand ready if your body should ever be exposed again. The intelligence of your immune system learns that virus and remembers how to handle that virus with speed.
Some antibodies have this unique ability to stick to receptors on viruses, making them unable to attach to other cells. They also work by tagging viruses and sending macrophages to destroy them by eating up.
So you probably don’t have to worry about getting mumps again for the rest of your life if you had it once as a child. It is also why doctors, nurses, and patients have survived the Ebola virus. This disease was incurable at one time. And, this is why vaccinations work.
Babies naturally obtain passive humoral immunity while they are in the womb. They assimilate readymade antibodies from their mothers through the placenta and later on through breast milk. This works pretty well for a few months. However, the protection is temporary because passively obtained antibodies don’t live long in the new body. You can acquire this immunity as you grow up through a healthy lifestyle and gradually building up a healthy immune system to strengthen your defenses. Hence the name Adaptive Immunity. The stronger your Immune system, the greater is its ability to fight off infections. You can have a healthy immune system by doing the following:
- Eat antioxidant foods
- Take more zinc
- Sleep adequately
- Lead a healthy lifestyle
Having seen how a healthy Immune system combats infections and intruders and its importance in the era of pandemics and the germy world, Munulex has much to offer.
