Chapter 24: At a Glance Defenses against Microbial Invasion The skin and mucous membranes form barriers. Nonspecific internal defenses combat microbes. The Immune Response A successful immune response recognizes, overcomes, and remembers. Recognition Antibodies and t-cell receptors recognize and bind to foreign molecules, triggering the immune response. An antibody contains both receptor and effector regions. T-cell receptors bind antigen and trigger responses. The immune system can recognize millions of molecules. The immune system distinguishes "self" from "non-self." Attack Humoral immunity is produced by antibodies in blood. T cells produce cell-mediated immunity. Memory Medicine and the Immune Response Antibiotics slow down microbial reproduction. Vaccinations stimulate the development of memory cells. Allergies are inappropriately directed immune responses. An autoimmune disease is an immune response against some of the body's own molecules. An immune deficiency disease results from the inability to mount an effective immune response to infection. AIDS The human immunodeficiency virus is a retrovirus that infects and destroys helper T cells. HIV virus is transmitted by exchange of body fluids. There are partially effective treatments, but no cures, for AIDS. AIDS is one of many widespread, lethal diseases. Cancer Cancer is caused by mutation, activation, or suppression of genes that control cell division. Evolutionary Connections: "Unnatural Selection" - The Evolution of Drug-Resistant Pathogens Designed in cooperation with Andrew Stull and Steven Brunasso. Last Update - July 25, 1997
Designed in cooperation with Andrew Stull and Steven Brunasso. Last Update - July 25, 1997
Last Update - July 25, 1997