Main Topics Flashcards
Chain of Infection
- Infectious Agent
- Reservoir Host
- Portal of Exit
- Mode of Transmission
- Portal of Entry
- Susceptible Host
5 types of potentially pathogenic agents
- Viruses
- Bacteria
- Fungi
- Protozoa
- Helminths
Examples of Viral Disease
- Common cold
- Influenza A and B
- Herpes
- Infectious hepatitis (e.g., hepatitis B and C)
- Acquired immunodeficiency syndrome (AIDS), which is caused by the human immunodeficiency virus
Common Disease caused by Bacteria
- Tuberculosis
- Urinary tract infections
- Pneumonia
- Strep throat
Protozoa
Unicellular parasites that can replicate and multiply rapidly once inside the host
* Often seen in tropical climates which have large insect populations
Fungi
Can be unicellular or multicellular; mushrooms, molds, yeasts
Treatment for fungal infections
Antifungal agents:
*Topical for tinea infections: Lotrimin (clotrimazole)
*Vaginal Suppositories for candidiasis: Monostat (miconazole)
*Oral: Fluconazole (Diflucan), ketoconazole (Nizoral), terbinafine (Lamisil)
Helminths
Multicellular; tapeworms, roundworms, flatworms
Two ways antibodies can be acquired:
*Actively: the body actively makes antibodies after exposure of the disease causing organism. i.e. vaccines, having the disease
*Passively: the body is given the antibodies without having to work for them. i.e. immunoglobulins, mother to child.
the body’s 3 lines of defense against pathogenic invasion:
1st Line: Physical barriers; The skin, Tears, Cilia, Mucous membranes, Defecation/vomiting
2nd line: Chemical/Cellular; phagocytic cells engulf and destroy the microbe, causing inflammation.
3rd line: Specific immunity: The body responds by creating antibodies specifically designed to combat foreign substances
Humoral Immunity
The immune system responds by producing antibodies specifically designed to combat the presence of a foreign substance, or antigen.
*responsibility of the body’s B cells
Cell-mediated Immunity
causes the destruction of pathogenic cells at the site of invasion or infection
Erythema
redness
edema
swelling
What happens when the body is exposed to an infectious agent/foreign sybstance?
inflammation mediators ( i.e. histamine, prostaglandins, and kinins) are released, causing 3 different responses:
1. blood vessels at the site dilate, causing an increase in local blood flow, which results in redness (inflammation) and heat. Blood vessel walls become more permeable, which allows for the movement of WBCs through the vessel wall
2. The WBCs begin to form a fibrous capsule around the site to protect surrounding cells from damage or infection. Blood plasma also filters out of the more permeable vessel walls, resulting in edema (swelling), which puts pressure on the nerves and causes pain.
3. The increased number of WBCs at the site results in phagocytosis. Destroyed pathogens, cells, and WBCs collect in the area and form a thick, white substance called pus.
