How does the human body and various microorganisms interact in terms of disease?

(page 315)
• virulence: “relative power of an organism to produce disease”
• resistance
• host
• pathogen
• contamination: “the act of introducing disease germs or infectious material into an area or substance”

• true pathogen: “an organism that due to its virulence is able to produce disease:
• attenuation: “dilution or weakening of virulence of a microorganism, reducing or abolishing pathogenicity”
• pathogenicity: “the state of producing or being able to produce pathological changes and disease”

• indigenous flora: “synonymous with normal flora, indicates the microbial population that lives with the host in a healthy condition”
• opportunists: “an organism that exists as part of the normal flora but may become pathogenic under certain conditions”
• drug-fast: “resistant, as in bacteria, to the action of a drug or drugs”

Page 316
Define local, focal, and general infections, and give an example of each.

• primary: “the first infection that a host has after a period of health”
• secondary: “infection caused by a different organism than the one causing the primary infection
• mixed: “infection caused by two or more organisms” (Fig. 24-2 page 317)
• blood: viremia; bacteremia

Page 316
Define septicemia and toxemia and include an example of each. What are the symptoms/characteristics for septicemia and toxemia?
Color Plate 38

• Readings question #3: Page 319
Describe toxins, exotoxins, and endotoxins, and give an example of each.

(Page 323)
• Direct: viral respiratory disease, staphylococcal infections, hepatitis A, measles, scarlet fever,
STDs, AIDS, infectious mononucleosis
- hand washing, gloves etc.
• Indirect:
Readings question #4: Describe the four primary mechanisms of indirect contact.
Include examples with each mechanism.
What are fomites?

• Page 326
• What is a vector? What are biological and mechanical vectors? Give an example of each.

• Page 329
• mechanical defenses
• physiological defenses
• chemical defenses

• Skin: epithelium (epidermis), sebaceous glands, dryness, “necrobiosis”
• Eyes: lacrimal apparatus
• Saliva: cleansing action
• Respiratory Tract: mucus, ciliated epithelium
• Urinary Tract: flushing action

• Page 331
• Inflammation: pus
• Fever: 102-104 degrees
• Phagocytosis: phagocyte ingests material
- Page 332 Figure 24-8

• Lysozome: enzyme that breaks down cell walls of gram-positive bacteria and some gram-negative bacteria
• Sebum: sebaceous glands, oily substance, protective film, lowers skin pH
• Gastric Juice: HCl, enzymes, mucus, acidic
• Interferon: eukaryotic cells, surface receptors

• Page 333
• Latin immunis “to exempt”
• Why is it that some people tend to be sick more often than others?
• Why can two people eat the same infected chicken, and only one person contracts food poisening?
• children, elderly, immunocompromised

• “a foreign substance that stimulates the formation of antibodies that react specifically with it”
• substance that provoke a specific response
• Antibodies: “glycoprotein substance developed by the body in response to, and interacting specifically, with an antigen. Also known as immunoglobulin.”

• 1) destroy pathogens by neutralizing the toxins the pathogen produces
• 2) coat the pathogen with a substance that attracts phagocytes by forming a substance that clumps the antigens together
• 3) prevent the pathogen from adhering to the body’s cells

• Page 334
• Natural (Innate)
• Acquired: Naturally Acquired – active, passive
Artificially Acquired
- active: vaccines
- passive: antibodies immune serums

• “an acquired, abnormal immune response to a substance (allergen) that does not normally cause a reaction”
• Immediate: 2 – 30 minutes
– systemic (shock, breathing difficulties)
– Localized (hay fever, asthma, hives)
• Delayed: 1-2 days
– TB skin test, contact dermatitis