Innate Immune System

Question 1

1st line of defence

Answer 1

External barrier

• physical barriers
• chemical barriers

Question 2

What are the physical barriers?

Answer 2

• mucus
• cilia ‘
• skin
• trachea
• nose

Question 3

What is mucus?

Answer 3

• thick and sticky substance that coats all open cavities that are exposed to the external environment.
• mucus traps pathogens to prevent them from entering

Question 4

Cilia

Answer 4

• tiny hairs that beat and sweep mucud containing pathogens out of the open cavity

Question 5

trachea

Answer 5

contains mucus and hair to protect the lungs

Question 6

nose

Answer 6

nose hairs and mucus

Question 7

skin

Answer 7

• made up of dead cells so viruses cannot infect and reproduce in cells - poor environment for growth
• well supplied with blood which contain white blood cells
• contains beneficial bacteria which kill harmful pathogens

Question 8

chemical barier

Answer 8

• tears
• salivia
• sweat
• stomach
• large intestines
• bladder
• reproductive and anal passages
• small intestines
• lysozomes

Question 9

tears

Answer 9

contain lysozomes and wash the eye with each blink

Question 10

sweat

Answer 10

sebum (oil) is broken down by skins bacteria to make lactic acid which inhibits fungal and bacterial growth

Question 11

stomach

Answer 11

contains stomach acid to kill pathogens

Question 12

large intestines

Answer 12

contains microflora

Question 13

bladder

Answer 13

contains acidic urine which cleans the urinary tract

Question 14

reproductive and anal passages

Answer 14

acidic environment

Question 15

small intestines

Answer 15

contains microflora which are harmless, in the gut and reproctive tract

these bacteria and fungus compete with each other for resources in the body which balances tyhe popuations and prevents overgrowth

Question 16

lysozomes

Answer 16

anti-bacterial enzymes which destoryg the cell wall of bacteria

Question 17

2nd line of defence

Answer 17

this is a defence adaptation that is inherited and non-specific to pathogens

Question 18

FIP

Answer 18

fever
inflammation
phagocutosis

Question 19

fever

Answer 19

increased temperature due to pyrogens via an inhospitable environment

Question 20

inflammation

Answer 20

dilation of blood vessels to bring increased blood flow to the infected area

Question 21

how does inflammation work

Answer 21

1. the injured cell releases chemokine. The cell can become “injured” when infected by pathogens or as a result of harmfulo pathogen toxins
2. chemokines promote basophils and mast cells to release prostoglandin and histamine
3. blood vessels dilate to increse blood flow to the infected area. Blood brings heat and more white blood cells which increases the rate of pathogen death through phagocytosis.

Question 22

phagocytosis

Answer 22

the process of engulfing and destroying any foreign body that phagocytes detect

Question 23

two types of phagicytes

Answer 23

neurtophils and macrophage

Question 24

neutrophils

Answer 24

• die immediately after engulfing the pathogen

Question 25

macrophage

Answer 25

• can kill up to 100 pathogens and are antigen-presenting

Question 26

process of neutriphils during phagocytosis

Answer 26

1. neutrophils scans the pasthoigen and realises that it is foreign
2. neutrophils engullfs the pathogen through endocytosis. it basically wraps around the pathogen.
3. lysosomes in the neutrophil contain digestive enzymes that break down the pathogen into smaller framents.
4. the neutophil releases the digested pathogen throuh exyocytosis

Question 27

process od macrophage killing pathogen

Answer 27

1.macrophage scans the pasthoigen and realises that it is foreign
2.macrophage engullfs the pathogen through endocytosis. it basically wraps around the pathogen.
3. lysosomes in the macrophage contain digestive enzymes that break down the pathogen into smaller framents.
4. the macrophage releases the digested pathogen throuh exyocytosis
5. macrophage displays a piece of the pathogen on its surface