Life on Earth
Audesirk & Audesirk
Prentice-Hall, Inc.


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

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