Term
| What are the six definitions of nonspecific host defenses? |
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Definition
- Innate - in born in every human.
- Provide a general protective response against any pathogen.
- Function in the same way aginst all MOs
- Vary in strength from person to person
- Do not depend on previous exposure to the MO
- Not effected by prior contact to the MO
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Term
| What are the four main first-line nonspecific host defenses (Surface Defenses)? |
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Definition
- Structural
- Mechanical
- Biochemical
- Normal Flora
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Term
| What are the two structural defenses? |
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Definition
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Term
| What are the key characteristics of skin? |
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Definition
- Thick physical barrier (epidermidis)
- Continually replaced
- Maintains normal flora
- Intact skin is a good barrier
- Damaged skin allows MOs in
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Term
| What are the key characteristics of the mucous membranes? |
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Definition
- Line the GIT, RT, and GUT
- Secrete mucous
- Intact mucosa is a good barrier but not as strong as skin
- Some MOs can penetrate mucous membranes if enough:
- Treponema pallidum
- Mycobacterium tuberculosis
- Streptococcus pneumoniae
- Neisseria gonorrhoeae
- HIV
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Term
| What are the three mechanical defenses (movements)? |
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Definition
- Muscular Activity of Wall of Intestines - keeps food moving with pathogens (peristalsis)
- Mucociliary System
Mucous - trap bacteria
Cilia - move, beat to expell MOs or move them to the stomach for digestion. - Washing Action
Urine - expels MOs as it flows out urethra
Tears - constantly moving across eyes, flushing MOs
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Term
How does normal flora act in the first-line defense? |
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Definition
- normal flora in the right place, numbers and species provide microbial antagonism.
- Microbial antagonism (competition) is competition between normal flora and pathogens (prevent growth) and between normal flora and normal flora (prevents overgrowth of NF)
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