Be immuned to Immunology

When we usually talk about immunology, most of us think about white blood cells first. Recalling back to my previous post on the innate immune system, I stated that the innate immune cells are the front line of defence. However, let's not forget our epithelia. Skin Your skin is like an armour that protects your whole body from the environmental pathogens. It serves as a physical barrier, which blocks any pathogen from entering your system. The many layers of skin makes it much more difficult for any pathogen invasion. Also, in the epidermal layer, there are Langerhan's cells (epidermal dendritic cells) which will act to capture pathogens, and present it to T cells to activate them. Innate immune cells can be most commonly found in the skin, so that they are able to get rid of pathogen immediately. Now, the skin usually protects the whole body from external pathogens. However, there are 2 openings which can increase the chance of pathogen invasion. The mouth and nosetril...