Week 9

Question 1

What are the 3 lines of defence?

Answer 1

1st
2nd
3rd

Question 2

Briefly describe the first line of defence.

Answer 2

Non-specific so acts as a defence against any pathogen

Question 3

Is the first line of defence specific?

Answer 3

No

Question 4

What type of pathogens does the first line of defence act on?

Answer 4

All

Question 5

Briefly describe the second line of defence.

Answer 5

Specific for bacteria and viruses.

Question 6

Describe the specificity of the second line of defence

Answer 6

Specific to viruses and bacteria

Question 7

What the of pathogens does the second line of defence act on?

Answer 7

Viruses and bacteria

Question 8

Briefly describe the third line of defence

Answer 8

Specific for a particular pathogen

Question 9

Describe the specificity of the third line of defence

Answer 9

Specific for a particular pathogen

Question 10

What are innate defences against pathogens?

Answer 10

Mechanical barriers which prevent entry and help undergo phagocytosis.

Question 11

If a pathogen manages to invade the body, what type of reaction occurs and why?

Answer 11

Inflammatory reaction to keep the infection contained.

Question 12

What is the general purpose of an inflammatory reaction in the body?

Answer 12

To keep an infection localised and prevent its spread.

Question 13

When is the first line of defence against pathogens present?

Answer 13

Constantly because it is innate (natural).

Question 14

Is the first line of defence against pathogens physical or chemical?

Answer 14

Both

Question 15

What is the first line of defence for the eyes and how does this work?

Answer 15

Lysozymes in the tears and other secretions dissolve pathogen cell walls.

Question 16

How does the skin act as part of the first line of defence?

Answer 16

Acts as a physical barrier.

Produces antimicrobial fatty acids and is normal flora inhibits pathogen colonisation.

Question 17

How does the stomach prevent pathogenic growth?

Answer 17

Has rapid changes in pH

Question 18

How is colonisation of pathogens prevented in the urinary tract?

Answer 18

Flushing of the urinary tract.

Question 19

How are pathogens expelled from the nose?

Answer 19

Removal of particles by rapid passage of air over cilia in the nasopharynx.

Question 20

How are microorganisms prevented from entering the body via the trachea?

Answer 20

Microorganisms are suspended in the mucus and are moved out of the body by the cilia.

Question 21

What prevents phagocytic colonisation in the lungs?

Answer 21

Mucus and phagocytes.

Question 22

In the intestines, what prevents bacterial growth?

Answer 22

The normal bacterial flora.

Question 23

What is the overall purpose of the second line of defence against pathogens?

Answer 23

Used to localise infection, neutralise toxins and repair tissue damage.

Question 24

What is the third line of defence against pathogens mediated by?

Answer 24

Antibodies and cells

Question 25

What are the cardinal signs of acute inflammation?

Answer 25

``` Redness. Swelling. Heat. Pain. (Loss of function). ```

Question 26

What are the factors that transmission of pathogens depends on?

Answer 26

Number of microorganisms shed. Microorganisms stability in the environment. Number of microorganisms required to infect the new host.

Question 27

What is a reservoir of infection?

Answer 27

The population of organisms or the specific environment in which an infectious pathogen naturally lives and reproduces, or upon which the pathogen primarily depends for its survival.

Question 28

What must a disease have to persist in a community that is not it's natural habitat?

Answer 28

A reservoir or continual source of organisms that are either living or non-living.

Question 29

What are the types of disease reservoirs.

Answer 29

Human Animal Insect

Question 30

Give examples of non-living disease reservoirs.

Answer 30

Soil Water Air Food

Question 31

What are zoonoses?

Answer 31

Diseases which can be transmitted between humans and animals.

Question 32

Name some portals of exit for microorganisms from a human

Answer 32

Ear via ear wax. Broken skin via blood. Skin. Anus via faeces. Eyes via tears. Nose via secretions. Mouth via saliva. Mammary glands in females via milk. Vagina via discharge or blood. Urethra via urine. Seminal vesicles via semen and lubricating secretions.

Question 33

What are the 3 categories of microorganism transmission ?

Answer 33

Contact transmission Vehicle transmission Vector transmission

Question 34

What are the types of contact transmission for microorganisms?

Answer 34

Direct contact. Indirect contact. Droplet transmission.

Question 35

How are pathogens spread via indirect contact ?

Answer 35

They are spread from one host to another via fomites.

Question 36

What are fomites?

Answer 36

Inanimate objects that are used to transfer pathogens to a new host.

Question 37

What are the sub-types of vehicle transmission of pathogens?

Answer 37

Airborne Water borne Food bone

Question 38

What are the 2 types of vector transmission of pathogens ?

Answer 38

Biological vectors | Mechanical vectors

Question 39

What are biological vectors?

Answer 39

They transmit pathogens and act as a host for multiplication.

Question 40

Give some examples of biological vectors.

Answer 40

Insects, ticks and mites.

Question 41

What are mechanical vectors of pathogens?

Answer 41

They are insects that carry pathogens passively.

Question 42

What are the types of person-to-person transmission ?

Answer 42

``` Respiratory Salivary Venereal Faecal-oral Skin Blood ```

Question 43

How are pathogens passed from person-to-person via the respiratory routes?

Answer 43

When people sneeze or cough particles containing the pathogen will be in each particle and will be transmitted to others.

Question 44

When is respiratory person-to-person transmission of disease increased?

Answer 44

In crowded conditions

Question 45

How are diseases spread person-to-person via the general route?

Answer 45

Generally spread as a result of mucosal contact.

Question 46

How are faecal-oral measures of disease transmission reduced?

Answer 46

Adequate sewage disposal and purified water.

Question 47

How are diseases spread via the faecal-oral route in more developed countries ?

Answer 47

Via food and fingers.

Question 48

How are diseases spread via the faecal oral route in less developed countries ?

Answer 48

Via water and flies.

Question 49

How are diseases spread via the skin?

Answer 49

Through shedding from the hair, skin and nails or direct contact.

Question 50

Describe horizontal transmission of disease.

Answer 50

Exponential. Most common in crowds.

Question 51

When is horizontal disease transmission most common?

Answer 51

In crowds.

Question 52

Give examples of vertical disease transmission.

Answer 52

Mother to baby through the placenta or at childbirth via the milk.

Question 53

What is meant by systemic infection?

Answer 53

When the blood becomes infected.

Question 54

Where in the body does mycobacterium tuberculosis infect?

Answer 54

The lungs.

Question 55

How is mycobacterium tuberculosis spread?

Answer 55

Respiratory aerosols.

Question 56

Where in the body does Neisseria Gonorrhoea infect?

Answer 56

The urogenital tract.

Question 57

Where in the body does Vibrio Cholerae infect?

Answer 57

Gastrointestinal tract.

Question 58

What is the portal of entry for vibrio cholera?

Answer 58

The mouth via contaminated food or water.