An Overview Of Pathogen Biology In The Immune System

            The Immune system is the body’s overall defense system against harm causing invaders, that come from the outside world, that are able to inter the body one way or another. The immune system is not an organ or two that do all the work, but rather a network of parts all throughout the body that works with other bodily systems to fight off viruses, diseases, infections, and anything that the immune system knows does not belong in the body.

            A pathogen is any organism or virus that can cause a disease after entering the body. The first line of defense against pathogens are external barriers such as the skin. The nose has nostril hairs act like a filter for elements entering the body through the nose. The nose can also fill with mucus that can exit the body to get rid of any pathogens that might enter the nostrils. The eyes have eye lashes that can wave away pathogen’s when a person blinks. The average person blinks about 16 times a minute. That is typically enough to keep out pathogens floating in the nearby air. According to Campbell Essential Biology with Physiology 4th Edition (2012):

External barriers also include chemical defenses in the form of antimicrobial secretions. Sweat, saliva, and tears contain enzymes that disrupt bacterial cell walls. Glands produce oils and acids that make the skin inhospitable