Chapter 14

Chapter 14 - Chapter 14 Nonspecific Defense of the Host...

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Chapter 14 Nonspecific Defense of the Host Defense Mechanisms 0 •Innate, nonspecific 0 –1st line of defense - (anatomical and physiological barriers) 1 –2nd line of defense (cellular and chemical symptoms 1 •Acquired, specific, 3rd line 0 –Naturally acquired 0 Active (infection) 1 Passive (maternal antibodies) 1 –Artificially Acquired 0 Active - vaccination 1 Passive - immune serum 1 1st Line of Defense 0 •Physical factors 0 –Skin (consisting of 2 layers) 0 -Epidermis – outer thinner portion made of tightly packed cells (upper layer - dead cells) 1 -Dermis – inner thicker portion; provides strength to skin 2 -Infection can develop when the epithelial surface is broken 1 –Mucous Membranes 0 -Mucous membranes line the gastrointestinal, respiratory and genitourinary tract 1 -Epithelial layer secretes the mucous that maintains the surface of the membrane always moist 2 -Mucous membranes are more susceptible to infection than skin 2 3 Other Barriers 4 •Lacrimal apparatus 0 Provides washing action removal of microbes 5 •Ciliary escalator 0 Lower respiratory tract covered with cilia, propel mucous containing microorganisms upward 1 2 •Chemical factors 0 –Sebum - oily substance produced by skin; contains unsaturated fatty acids - inhibit the growth of certain bacteria 1 –Gastric juice - mixture of hydrochloric acid, enzymes and mucous, kills most of bacteria except Clostridium botulinum and staphylococcus aureus 2 –Lysozyme (in saliva and tears) - enzyme that hydrolyzes the peptidoglycan
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Second and Third Line of Defense: Immune System Responsible for: 3 –Surveillance of the body - white blood cells 4 –They recognize foreign material - distinguish between “self” and “nonself” 5 –Destruction of foreign entities Systems Involved in Immune Defenses
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This note was uploaded on 09/16/2011 for the course MCB 2000 taught by Professor Gantar during the Fall '08 term at FIU.

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Chapter 14 - Chapter 14 Nonspecific Defense of the Host...

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