Our Natural Defense System
- Janani Prasad
- Jun 23, 2020
- 3 min read
Disease. Infection. Viruses. These are the deadly predators that swear to destroy our body. But every human has a hero that protects itself from these dangers. That is our immune system. The immune system has been a prevalent subject in the news recently. Doctors say that having a healthy immune system will reduce your chances of getting severe Covid-19. But what exactly is the immune system?
What is the immune system?
Basically, the immune system is a complex network of cells that work to defend your body against infections. It also has special cells that keep a record of the infectious cell so that the body will have a better attack system if it is introduced to the same infection again. An abnormal immune system can be the cause of autoimmune disorders, allergic diseases, and immunodeficiencies. The process of defending the body involves many steps, but all of them have a similar pattern.
What are the main components of the Immune system?
Lymphatic system: removes toxins from the body
Lymph Nodes: B and T cells live here. Lymph Nodes are found all over the body (around 500).
Lymphocytes: different types of white blood cells
Antibodies: help fight off infections
Spleen: removes aged and damaged blood cells
Bone Marrow: production of B and T cells. B cell maturation site
Thymus: T cell maturation site
What is the process of the immune system?
The first line of defense in our body is our skin and mucosal membranes. Both prevent bacteria and viruses from getting inside. But let’s say that you scraped your knee while playing soccer. Now, that area is exposed to harmful bacteria and deadly viruses.
Once the bacteria/virus get inside, Mast cells release a chemical called histidine that sends signals to the brain to start the inflammatory response and activate the secondary response, the innate response. Macrophages - a type of white blood cells - come and eat the bacteria/virus cells. For the most part, this solves the problem for little cuts. But sometimes, macrophages are not enough to wipe out virulent illnesses.
This is when the third line of defense is activated, the adaptive immunity. The adaptive immunity response includes B cells - white blood cells that are produced in bone marrow - and T cells - white blood cells that are produced in bone marrow but mature in the Thymus. There are two stages of adaptive immunity: cell-mediated response and Humoral response. In the cell mediated response, Cytotoxic T-cells are released into the bloodstream. They destroy infected cells by injecting a protein called perforin, which enables the infected cell to undergo apoptosis (to self-destruct). The second part of adaptive immunity is the Humoral response. In this response, helper T-cells bind to antigens - flag-like structures - and stimulate B cells to produce antibodies which will destroy infectious cells.
Along with both these responses, memory B and T cells keep a “memory” of the infection. In the case of another infection by the same bacteria/virus, the memory cells will be able to recognize the bacteria/virus and stimulate a faster and more efficient immune response. These memory cells are the main reasons why vaccines work.
How do you build a strong immune system?
Don’t smoke
High vegetables and fruit diet
Exercise frequently
Get sufficient sleep
Lower stress
Conclusion
The immune system is a complicated procedure, but it is essential for our survival. It protects us from the many dangers of the world. Thanks to our immune system and advancements in medical technology, humans are able to live a long life.
Works Cited
Department of Health & Human Services. “Immune System.” Better Health Channel, Department of Health & Human Services, 30 Mar. 2014, www.betterhealth.vic.gov.au/health/conditionsandtreatments/immune-system.
Publishing, Harvard Health. “How to Boost Your Immune System.” Harvard Health, www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system.
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