The effects of aging on the immune system
The immune system is comprised of a vast number of cells and tissues, all working in tandem to defend us against foreign invaders. As we age, these cells and tissues start to decline. This decline affects both the innate and adaptive immune systems, ultimately leading to a weakened resistance to pathogens.
//Innate immunity is the first line of defense against pathogenic microbes. It is present in every tissue in our bodies, including our skin, epithelial lining of the respiratory tract, and the gastrointestinal tract. The innate immune system consists of physical barriers, like the skin or mucosa lining the lungs or digestive tract; inflammatory cells that can fight infection through phagocytosis or by producing inflammatory cytokines; and chemical barriers like acid in the stomach or lysozyme in tears that can destroy certain microorganisms. The innate immune system doesn’t change with age. However, it can become less effective over time as its chemical and physical barriers degrade.//
//The adaptive immune system is our body’s second line of defense against pathogens. It develops after an initial infection with a pathogen, allowing us to recognize future invasion by the same pathogen more quickly than we could before the infection occurred. Adaptive immunity relies on T-cells and B-cells that are produced in