6.2.2 - Entry Routes Of Pathogens

Question 1

What Are The 4 Main Ways That Pathogens Can Enter The Body?

Answer 1

~ Broken skin.
~ Digestive system.
~ Respiratory system.
~ Mucosal surfaces.

Question 2

How Can Pathogens Enter The Body Through Broken Skin?

Answer 2

They have direct access to the tissues and the bloodstream.

Question 3

How Can Pathogens Enter The Body Through The Digestive System?

Answer 3

When we consume contaminated food and drink.

Question 4

How Can Pathogens Enter The Body Through The Respiratory System?

Answer 4

As we inhale.

Question 5

How Can Pathogens Enter The Body Through Mucosal Surfaces?
(2 Points)

Answer 5

~ Through the lining of body cavities.
~ E.g. Inside the nose, mouth and genitals.

Question 6

What Are The 4 Barriers To Infection?

Answer 6

~ Skin.
~ Micro-organisms of the gut and skin.
~ Stomach acid.
~ Lysosyme.

Question 7

Describe Skin As A Barrier To Infection
(4 Points)

Answer 7

~ Provides a physical barrier against infection.
~ If damaged, leaves the exposed tissue beneath vulnerable to pathogens.
~ Blood clotting prevents pathogen entry when there is broken skin.
~ However, blood clotting takes time meaning pathogens can still get in.

Question 8

Describe Micro-organisms As A Barrier To Infection
(2 Points)

Answer 8

~ Known as gut or skin flora.
~ Compete with pathogens for natural resources (Space, water and nutrition), limiting their numbers and ability to infect.

Question 9

Describe Stomach Acid As A Barrier To Infection
(3 Points)

Answer 9

~ Contains hydrochloric acid at a pH level of 2, anything above a pH of 4 will be favourable to pathogens.
~ Creates an acidic environment unfavourable to many pathogens.
~ However sometimes a few pathogens are able to survive and infect.

Question 10

Describe Lysozyme As A Barrier To Infection
(3 Points)

Answer 10

~ Damages bacterial walls, causing them to burst.
~ Is a secretion of the mucosal surfaces.
~ E.g. Tears, saliva and mucus all contain lysozyme.