Immunity ➔

Apuntes

•Immunity Protection against disease provided by the body’s immune system. Innate immunity involves organs, tissues, and cells present at birth, such as the skin. Acquired immunity develops over time, either actively—through infection (natural) or vaccination (artificial)—or passively—by receiving antibodies from others. •Natural passive immunity Antibodies received from the mother, such as through breast milk. Newborns acquire antibodies crossing the placenta during pregnancy, which remain for months. Colostrum, produced in the first 4-5 days after birth, contains IgA antibodies that protect the infant’s gut by preventing bacterial and viral growth, some passing into the bloodstream. •Artificial passive immunity Obtained via medicines like gamma globulin injections or infusions. For fatal diseases requiring immediate defense, antitoxin injections provide quick but temporary protection, as the antibodies are foreign and are eventually removed by phagocytes. •External defence system Physical, chemical, and cellular barriers prevent pathogen entry. For example, blood clotting stops blood loss and blocks pathogen entry through skin wounds. •Internal defence system ...