Chapter 2

Question 1

What is the portal of exit?

Answer 1

Path by which a pathogen leaves its host.

Question 2

What corresponds to the site where the pathogen is localized?

Answer 2

Portal of exit.

Question 3

How do influenza viruses and TB exit the body?

Answer 3

They exit through the respiratory tract.

Question 4

How do schistosomes exit the body?

Answer 4

They exit through urine.

Question 5

How does cholera exit the body?

Answer 5

It exits through feces.

Question 6

How do scabies exit the body?

Answer 6

They exit through the skin.

Question 7

How do blood-borne organisms like rubella and syphilis exit the body?

Answer 7

They exit trans-placentally.

Question 8

How does Hepatitis B exit the body?

Answer 8

It exits through needle injuries.

Question 9

How does malaria exit the body?

Answer 9

It exits through mosquitoes (blood-sucking arthropods).

Question 10

What is the mode of transmission?

Answer 10

Method of transmission from reservoir to susceptible host.

Question 11

What are the direct modes of transmission?

Answer 11

Contact and droplet.

Question 12

What are the indirect modes of transmission?

Answer 12

Airborne, vehicle, and vector.

Question 13

What is contact transmission?

Answer 13

Transmission through skin-to-skin contact, kissing,kissing disease monoucleosis
sexual intercourse genorrhea, or contaminated soil.hookworm

Question 14

What is droplet transmission?

Answer 14

Spray with large (>5 microns) & short-range aerosols.
 Meningococcal infection
 Pertussis (whooping cough

Question 15

What is airborne transmission?

Answer 15

Infectious agents carried by dust or droplet nuclei (<5 microns) suspended in air.settled on surfaces and may be blown
over great distances by the wind.
 Measles

Question 16

What is vehicle transmission?

Answer 16

A substance such as food, water, blood, or contaminated materials transmits infectious agents.

Question 17

What is vector transmission?

Answer 17

Living organisms such as mosquitoes, fleas, or ticks transmit infectious agents.

Question 18

What is the portal of entry?

Answer 18

Path of entry of the pathogen to a susceptible host.

Question 19

How does the respiratory tract serve as a portal of entry?

Answer 19

It is the entry point for influenza.

Question 20

How does the fecal-oral route serve as a portal of entry?

Answer 20

Pathogen exits in feces and enters the mouth by contaminated food.

Question 21

How does the skin serve as a portal of entry?

Answer 21

It is the entry point for hookworm.

Question 22

How does blood serve as a portal of entry?

Answer 22

It is the entry point for HIV and HBV.

Question 23

How do mucous membranes serve as a portal of entry?

Answer 23

They are the entry point for syphilis.

Question 24

What is a susceptible host?

Answer 24

A person whose body defense mechanisms cannot withstand the invasion of a pathogen.

Question 25

What factors can make a host susceptible to disease?

Answer 25

Genetic factors and disrupting immunity due to malnutrition, disease, or therapy.

Question 26

What is the non-specific immune system?

Answer 26

Includes skin, mucous membranes, cilia in trachea, cough, and gastric acidity.

Question 27

What are the types of specific immunity?

Answer 27

Passive (trans-placental Ab or injection of antitoxin or Ig) and active (infection, vaccination, or toxoid).

Question 28

Vehicles carry pathogen either:

Answer 28

 Passive way (hepatitis A virus)  Active way (canned foods provide an environment suitable for production of toxin by Clostridium botulinum)

Question 29

Living organism such as mosquitoes, fleas or ticks transmit infectious agents to a susceptible host either

Answer 29

 Mechanical: on their appendages (shigella) or in their gut (plague).  Biological: malaria (maturation in mosquitoes