Pathophys Exam 2

Question 1

What determines the degree of Pathogenicity of a organism?

Answer 1

1) Virulence

2) The host’s defense

Question 2

Virulence Definition

Answer 2

The ability of a microorganism to produce disease.

Question 3

Virulence depends on?

Answer 3

1) Ability of organism to attach and enter host.
2) Ability of organism to produce endotoxins and exotoxins.
3) Ability of organism to induce host cell responses that cause injury.

Question 4

What are the Types of Host Defense?

Answer 4

1) Inflammatory response
2) Innate response
3) Acquired response

Question 5

Inflammatory Response

Answer 5

• Active process involving leukocytes and chemical mediators.
• The function is to kill the organism, to minimize damage, and to prevent further injury.

Question 6

Innate Response

Answer 6

• Non-specific immunity
• No memory
• Includes physical barriers like mucous membranes, epithelium (first line of defense), keratinized stratified squamous; environmental factors like pH and temperature; and also phagocytosis by netrophyls and macrophages.

Question 7

Acquired Response

Answer 7

• Highly specific
• Has memory
• Response to foreign substance improves with each exposure
• Includes Humeral (antibody and immunoglobulin mediated immunity) and cell mediated immunity.

Question 8

Sources of Infectious Diseases

Answer 8

1) Endogenous Organisms
2) Exogenous Organisms
3) Nosocomial Infections
4) Community Infections

Question 9

Endogenous Organisms

Answer 9

• Involves one own microflora, generally due to opportunistic organism.
• Generally due to impaired or supressed host’s defense system.

Question 10

Exogenous Organisms

Answer 10

• Derived from the external environment, humans, or animals.
• Can be from body fluids, blood, feces, urine, respiratory secretions, semen, saliva, tears, and any mucous associated with mucous membranes.

Question 11

Fomite

Answer 11

• It is a physical object that serves to transmit an infectious agent from person to person.
• Can be door knobs, combs, needles

Question 12

Nosocomial Infections

Answer 12

• Infection contracted at the hospital due to hospital stay.
• It’s secondary to patient’s original condition.
• Contracted within 48 hrs of hospitalization or up to 30 days after discharge.

Question 13

Community Infections

Answer 13

-Infections contracted outside of a health care facility.

Question 14

How organisms enter the body? (12)

Answer 14

1) Direct contact
2) Penetration wounds
3) Incision wounds
4) Abrasion, lacerations and avulsions
5) Deep puncture wounds
6) Inanimate objects
7) Insect bites and burrowing insects
8) Burrowing helminth larvae
9) Burns
10) Ingestion
11) Contaminated water
12) Inhalation

Question 15

Direct contact

Answer 15

• Exposure of intact mucous membrane or skin to contaminated tissue, fluids or fomites.
• Includes parasitic diseases like mites (scabies), lice, and dermatomycosis like ringworms and candida albican.
• Also STDs, HPV, strap and staph causing impetigo and folliculiti, transmission from mother to baby.

Question 16

Penetration wounds

Answer 16

-Causes breaching of epithelial barrier of body

Question 17

Acanthoamoeba

Answer 17

-Protozoan disease of cornea

Question 18

Incision wounds

Answer 18

• Cuts thru epithelium with sharp object
• Contamination may occur from the object or opportunistic organism.
• Staph and Strep are the most common for incision infections.

Question 19

Abrasion, lacerations and avulsions

Answer 19

• May involve opportunistic or environmental pathogens.
• Associated with more tissue trauma and therefore more necrosis.
• Most often bacterial infections but fungi may occur.

Question 20

Deep puncture wounds

Answer 20

• Penetration of deeper tissue with closure of tissue surface with a clot.
• Causes damage and inoculation of tissues with microorganisms.
• Ex: animal bites, gram negative and anaerobic bacteria with endo and exo toxin release as when stepping on nails

Question 21

Inanimate objects

Answer 21

• May involve same organisms from abrasions, lacerations and avulsions.
• Most concerning are the anerobic organisms such as clostridium tetani that can cause devastating systemic effects.

Question 22

Some Organisms involved in Abrasion, Lacerations and Avulsions

Answer 22

• staph aureus
• strep epidermis
• psedomonas aeroginosa
• hemophilus influenza
• clostridium species

Question 23

Insect bites and burrowing insects

Answer 23

• Fleas- give staph, strep, and yersinia pestis (plague)
• Lice- Richettsia peovwazekii - thyphus
• Assassin bug- chagas disease
• Ticks- Rocky Mt Spotted Fever (rickttsia rickttii), Lyme’s disease (borrelia burgdorferi)
• Mosquitoes- yellow fever, Viral encephalitis, West Nile fever, malaria (plasmadium), heart worm disease (helminth)

Question 24

Burrowing helminth Larvae

Answer 24

-Can penetrate skin soon after hatchin

Question 25

Cutaneous larval migrans

Answer 25

-Body migration of hookworms and round worms larvae