Primary non-specific defences

Question 1

What is non-specific defence?

Answer 1

It doesn’t distinguish on pathogen from another

Question 2

What is specific defence?

Answer 2

Recognition of a pathogen by lymphocytes and immunity is developed

Question 3

What are the non-specific defence mechanisms?

Answer 3

First and second line of defence

Question 4

What is first line of defence?

Answer 4

Skin, mucous membranes and secretions of skin

Question 5

What is second line of defence?

Answer 5

Phagocytic white blood cell, anti-microbial proteins and inflammatory response

Question 6

What is the specific defence mechanism?

Answer 6

Third line of defence

Question 7

What is the third line of defence?

Answer 7

Lymphocytes, antibodies and memory cells

Question 8

What are the 2 types of disease transmission?

Answer 8

Horizontal and vertical

Question 9

What is horizontal transmission?

Answer 9

From person to person

Question 10

What is vertical transmission?

Answer 10

From parent to unborn child

Question 11

What is the purpose of primary defences?

Answer 11

Stop pathogens from entering body

Question 12

When is secondary defences used?

Answer 12

If pathogens are in the body

Question 13

What is direct transmission?

Answer 13

Contact with another person, breaks in skin and ingestion

Question 14

What is indirect transmission?

Answer 14

Droplets on surface, inanimate fomites and vectors

Question 15

How does the stomach quickly expel contents?

Answer 15

The vomiting reflex

Question 16

What is the purpose of vomiting?

Answer 16

To quickly remove harmful substances from the gut

Question 17

What is function of diarrhoea?

Answer 17

A host defence to eliminate the pathogen or it may be a pathogen microbial adaptation to ease/allow transmission to other hoss

Question 18

He is the eye adapted as defence?

Answer 18

Tears wash away and blinking drains fluid, lysosome present in tears (degrades peptidoglycan in bacterial cell walls) so is anti-microbial and macrophages present

Question 19

How is the body adapted defence to airborne transmission?

Answer 19

Trachea contains mucous and epithelial cells which trap particles and beat up to throat to be swallowed and in alveoli, many macrophages phagocytose any particles missed by mucous

Question 20

How is the skin adapted to defence?

Answer 20

There is a high NaCl concentration in sweat so is osmotically stressful for microbes, antimicrobial substances produced on skin surface and it regenerates

Question 21

What is the structure of the skin?

Answer 21

It is made of hard layers of dead cells, is very dry and has a pH of 5.5

Question 22

Why is the nose and mouth adapted to defence?

Answer 22

Gastrointestinal tract is major entry point for pathogens as tears, saliva and lung secretions swallowed

Question 23

How is the nose and mouth adapted to defence?

Answer 23

Saliva contains the enzyme lysosome and general antibodies, throat restricts airflow so microbes settle out and nose filters air which traps microbes in nasal mucous

Question 24

How is the stomach adapted to defence?

Answer 24

It has a very low pH, a thick layer of mucous, contains protein digesting enzymes which denature toxins and stomach lining cells are constantly shed as food scrapes past so hard for pathogens to attach

Question 25

What is blood clotting?

Answer 25

It blocks wound and platelets are activated

Question 26

What is the purpose of blood clotting?

Answer 26

To stop blood loss and pathogen entry

Question 27

What is inflammation?

Answer 27

Isolation of bacteria when wound breaks skin and bacteria enters

Question 28

What is the process of inflammation?

Answer 28

1. Mast cells release histamine and cytokines
2. Blood vessels dilate to increase blood flow, increasing heat which prevents pathogens dividing.
3. Blood vessels become more leaky (more tissue fluid and swelling) to dilute and wash away pathogens.
4. Cytokines attract neutrophils to phagocytose pathogens