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Life on Earth
Chapter 24 Defenses Against Disease: The Immune Response |
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| At a Glance |
  
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- 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
- The skin and mucous membranes form barriers.
