Understanding the Immune System (Part 1)
We are starting a series of articles of articles on understanding the immune system as laughter has a profound effect on it. Scientific studies have shown that laughter affects different components of the immune system, thereby making it important to understand different types of immunity.
What is immune system: The immune system is a defense mechanism which protects us from foreign invaders like bacteria, viruses, fungi and parasites. The disorders of the immune system can lead to autoimmune diseases, inflammatory diseases and even cancer. Immune deficiency can occur when our immune system is less active than normal, resulting in life threatening infections. It can be genetic or acquired such as HIV/AIDS. This deficiency can also occur by using immuno suppressant medicines like steroids or chemotherapy.
Autoimmune diseases: These result from a hyperactive immune system attacking our own body cells as if they are foreign organisms. Some common autoimmune diseases are Hashimoto’s thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, systemic lupus erythmatosus (SLE)
Innate immune system: We are all born with some level of immunity, which is our first defence against all pathogens. The first barrier is our skin which covers the body protecting us from these invaders. Then we have our respiratory system, gastrointestinal tract, urinary system and the internal mucus membrane lining, all of which act as barriers against micro-organisms. We also have some chemical barriers in the form of tears, saliva and stomach acids which can kill micro-organisms. There is a cellular defense mechanism in the form of white blood cells which can attack the pathogens and also natural killer cells which can destroy tumour cells.
Adapted or Acquired immune system: As we grow, we are exposed to a variety of pathogens and slowly our body develops immunity against them. Our immune system develops antibodies or special type of proteins which protects these pathogens from entering our body again. This is also referred to as immunological memory, because our immune system remembers its previous enemies.
Passive immunity: This type of immunity is borrowed from another source and does not last long. For instance, a baby receives antibodies from the mother through the placenta before birth and from breast milk after birth. This passive immunity protects the babies from infections in the early years of life.
Blood-Brain Barrier (BBB): It is a highly selective filter – a semi-permeable membrane that separates blood circulation from the brain and cerebrospinal fluid in the central nervous system. It prevents potential neuro-toxins, bacteria and viruses from entering our brain and spinal cord.