Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
11 Cards in this Set
- Front
- Back
|
List and discuss the five fundamental requirements for a pathogen to successfully infect a host.
|
1. Enter the host (portal of entry)
2. Establishment (sticking) 3. Avoid, evade, or compromise, the host's defenses 4. Damage the host (virulence factors) 5. Exit the host (portal of exit) |
|
|
Identify and describe the portals through which pathogens invade the body
|
Skin - Large surface area *populated (hair follicle, duct, break in skin)
Mucous Membrane - Respiratory tract, favorable route, aerosol droplets, dust particles (cold, influenza, TB, whooping cough, pneumonia) gastrointestinal tract, **fecal-oral route of contamination (most common mode of transport)**, food and beverage, genitourinary tract, UTI (most common in nurses), STI (Genital warts chlamydia, gonorrhea, genital herpes, syphilis, HIV) Placenta Parenteral Route - mechanism by which a pathogen is deposited into tissues beneath skin or mucus membranes, punctures, bites, stab wounds, cuts, surgery. |
|
|
Identify and describe the portals of exit that pathogens take from the hosts body.
|
Secretions - eyes, ears, nose, mouth
Skin - flakes or blood Blood - needles, bites, wounds Vaginal secretions/semen Excreted body wastes Urine, feces, sweat |
|
|
Explain how microbes adhere to host cells and why this is important to pathogenicity
|
It is important to be able to stick to a host and stay on the host long enough to do damage
|
|
|
List the types of adhesion factors and the roles they play in infection.
|
Glycocalyx, flagella, fimbrae these all have a sticky outer coat that allow for sticking onto the host. Attachment proteins. Viruses & Bacteria
|
|
|
Define ID50 and LD50 and describe their role in the virulence of pathogens.
|
ID50 - Infectious dose, how small or large of a dose that infects 50% of the population. (The number of organisms required for 50% of population to show signs of infection)
LD50 - Lethal dose. The number of organisms required to kill 50% of the population. **Pathogens having the lowest LD50 and ID50 values are more virulent. |
|
|
Describe the different strategies pathogens employ to avoid, evade, or compromise host defense systems.
|
Some bacteria have ways to prevent phagocytosis or even lead to partial phagocytosis.
|
|
|
Explain how capsules and cell wall components contribute to pathogenicity.
|
Capsules and cell walls camouflage the disease so she WBC is checking for disease or foreign objects, it goes unnoticed and is able o break out later. Are able to grow and pultiply and become stronger. p. 87
|
|
|
Describe the role of enzymes (leukocidins, hemolysis, coagulase, kinases, hysaluronidase, and collagenase) in a pathogen's virulence.
|
Leukocidins - chemicals that kill WBC
Hemolysins - Enzymes that break down RBC Hyaluronidase - Breaks down connective tissue and collagen in host, which allows for infection to spread. Collagenase is the same as hyaluronidase. |
|
|
Compare and contrast the nature and effects of exotoxins and endotoxins.
|
Exotoxins - toxins that are produced by pathogens and then leave the pathogen cells and enter host cells. MOST LETHAL SUBSTANCE KNOWN.
Potent, protein (1. cytotoxins - kill cells that they come in contact with, anthrax toxin and dipitheria toxin. 2. Neurotoxins - interfere with neurological signal transmission. Tetanus & Botulinum. 3. Enterotoxins - affect lining of digestive system. Digestive tract/diarrhea. Vibrio toxin - Antitoxins - chemicals that break down and destroy Endotoxins - bacterial toxins that are part of the cell wall of Gram-negative bacteria. Only active when the bacteria that was carrying them was killed. Not as potent as Exotoxins. Lipid A (Gram-positive), Chills, fever, muscle weakness, aches. Disseminated intravascular clotting (can be treated with IV) |
|
|
Basics of Chapter 5
|
CONTAMINATION --> Port of Entry --> adhere (stick/stay ex. glycocalyx) --> avoid host defenses (avoiding phagocytosis) --> virulence factors (what makes a pathogen) --> INFECTION --> DISEASE
|
