How does adult body defend itself from infection caused by bacteria or virus?
Human body has a defense systems build in to fight against various types of infections or so called foreign body attacks. When, bacteria or viruses (foreign body) break physical barriers like skin and enter into our blood stream, then our immune system react in two ways 1. recognize that foreign body has entered and 2. respond to the foreign body to fight against it White Blood Cells (WBC), also know as leukocytes, are present in blood and are responsible for fighting against infection and foreign bodies. Surface of the white blood cells have “Toll-like receptors (TLRs)”, which are able to distinguish different types of foreign bodies that can cause infection. Although, biologically, TLR mechanism is complicated, but in simple terms, TLRs can be imagined as antenna that have capability to catch different frequencies and enable us to watch different channels on TV or listen to programs on Radio. After recognition of foreign body by TLRs, TLRs send signals to various cells and genes and
