PATHOLOGY

Detailed explanation-1: -External defense systems include your skin, tears, mucus, saliva, stomach acid, cilia (small hairs) and helpful bacteria in your bowel. Your skin provides a physical block to stop bacteria and viruses from finding their way straight into your blood.

Detailed explanation-2: -Internal Defenses. When pathogens enter the body, the innate immune system responds with a variety of internal defenses. These include the inflammatory response, phagocytosis, natural killer cells, and the complement system. White blood cells in the blood and lymph recognize pathogens as foreign to the body.

Detailed explanation-3: -Inflammation is the immune system’s response to harmful stimuli, such as pathogens, damaged cells, toxic compounds, or irradiation [1], and acts by removing injurious stimuli and initiating the healing process [2]. Inflammation is therefore a defense mechanism that is vital to health [3].

Detailed explanation-4: -Natural Barriers Against Infection. The Blood. Inflammation. Immune Response. Fever.