Diseases --> Semester 2

Question 1

Disease definition –> and the 3 types

Answer 1

A condition or change that negatively impacts the normal functioning of an organism.
the three types are:
- non-infectious
- congenital
- infectious

Question 2

Infectious disease definition

Answer 2

can be spread
transmitted from organism to organism. all are caused by pathogens

Question 3

Non-infectious disease definition

Answer 3

cannot be spread
disease that cannot be passed from one individual to another, they are caused by physical factors

Question 4

Pathogen and 5 Types

Answer 4

A pathogen is an organism causing disease to its host,

viruses, bacteria, parasites, fungi, protists

Question 5

what is Airborne transmission

Answer 5

airborne droplets remain suspended in the air.

commonly transmitted through small respiratory droplets. These droplets are displaced when someone with the airborne disease sneezes, coughs, laughs, or otherwise exhales in some way.

Question 6

what is Vector-borne transmission

Answer 6

vectors such as arthropods are living carriers of pathogens. Occurs when a pathogen lives on the surface of the vector, pathogen transmitted directly from vector to host

Question 7

what is Contact Transmission

Answer 7

direct or indirect
pathogen being transmitted from person to person (touching, kissing, or sexual contact)

Question 8

what is Vehicle transmission

Answer 8

non-living pathogen carriers. called fomites (clothes, utensils, furniture, door-knobs)

Question 9

1st line

Answer 9

Physical
- skin (keratin)

Chemical
- lysozyme
- mucus
- stomach acid

Mechanical
- coughing
- sneezing

Question 10

2nd line

Answer 10

Complement system
- 25 proteins

Interferons
- proteins that disrupt viral replication

Inflammation
- involves phagocytosis

Question 11

how can an increase in core body temp help body fight against infection

Answer 11

slows down pathogen growth and increases the rate of phagocytosis by WBC (white blood cells)

Question 12

phagocytes have an organelle called what? and what does it contain?

Answer 12

lysosomes that contain digestive enzymes for destroying pathogens

Question 13

what system and fluid can WBC be found?

Answer 13

lymphatic system and lymph fluid

Question 14

3 lines of defence

Answer 14

1. physical, chemical & mechanical barriers
2. non-specific (innate)- immune system
3. specific (adaptive)- immune system

Question 15

Distinguish between the two types of immunity:

Answer 15

Innate (non-specific)
Acquired (specific)

Question 16

how can the immune system distinguish between non-self cells and self cells?

Answer 16

by recognising antigens.
–> signalling structures unique to a specific cell.

Question 17

why are antibodies only effective against a specific pathogen?

Answer 17

the shape is complementary to the shape of antigen on pathogen

Question 18

t-cells are involved in what?

Answer 18

specific immune response to infection

Question 19

3 types of t-cells in specific immune response

Answer 19

cytotoxic t-cells
helper t-cells
memory t-cells

Question 20

cytotoxic t-cells?

Answer 20

release perforin and cause apoptosis

Question 21

helper t-cells?

Answer 21

help activate b-cells and cytotoxic t-cells

Question 22

memory t-cells?

Answer 22

contain antigens specific for certain pathogen

Question 23

4 points of entry

Answer 23

respiratory surfaces
wounds
digestive system
reproductive organs

Question 24

acquired? (adaptive?)

Answer 24

specific defences
- cell-mediated
- humoral

Question 25

innate?

Answer 25

non-specific defences - physical, chemical and mechanical - phagocytosis and inflammation

Question 26

phagocytosis is what?

Answer 26

The process when cell is trying to destroy something, - virus or infected cell, - often used by immune system cells.

Question 27

phagocytosis steps

Answer 27

1. engulfs pathogen 2. phagosome forms 3. phagosome fuse with lysosome --> phagolysosome 4. digestive acids and enzymes destroy pathogen 5. digested pieces released into extracellular space by exocytosis

Question 28

define immunity

Answer 28

ability of host to resist infectious disease

Question 29

categories of protection in non-specific immune response

Answer 29

physical and chemical barriers, the inflammatory response, and interferons.

Question 30

specific immune response is triggered by what

Answer 30

triggered by antigens

Question 31

example of physical protection

Answer 31

skin --> makes hard protective layer

Question 32

example of chemical protection

Answer 32

tears --> cells in eye produce and secrete range of chemicals including enzymes

Question 33

example of mechanical protection

Answer 33

blinking --> reflex action to irritation by particles (pathogens)

Question 34

what are non-self pathogens (molecules) called

Answer 34

antigens

Question 35

symptoms of inflammation

Answer 35

swelling heat redness pain

Question 36

what is an antigen

Answer 36

causes the body to make an immune response

Question 37

infection steps

Answer 37

1. host access gained 2. attachment to host cells 3. survive host defences 4. replicate and cause host cell apoptosis

Question 38

inflammation steps

Answer 38

1. bacteria invade, chemical messengers released (histamine). 2. platelets cause blood clot, WBC arrive 3. phagocytes (macrophages and neutrophils) digest bacteria, tissue heals

Question 39

what does a phagocyte do? and another name?

Answer 39

macrophage & neutrophils recognise, engulf and kill pathogens by process --> phagocytosis

Question 40

what do lysosomes do in phagocytosis

Answer 40

fuses with phagosome --> phagolysosome they consist of acids, oxidisers and enzyme these chemicals decompose/breakdown pathogens

Question 41

what do memory t-cells do

Answer 41

recognise/remember pathogen if returned

Question 42

how are cytotoxic t-cells activated?

Answer 42

interleukin-2 released by helper t-cells --> leads to development of cytotoxic t-cells

Question 43

what is role of cytotoxic t-cells in immune response?

Answer 43

detect antigen and release protein called perforin results in cell burst

Question 44

2 types of b cells

Answer 44

plasma cells and memory b cells

Question 45

congenital

Answer 45

genetically inherited

Question 46

all disease is caused by what?

Answer 46

pathogens

Question 47

epidemic

Answer 47

national spread of a disease

Question 48

pandemic

Answer 48

international spread of disease

Question 49

what cause the body to make immune responses

Answer 49

antigen

Question 50

role of interleukin1

Answer 50

activate B and T cells

Question 51

what is apoptosis

Answer 51

cell death

Question 52

3rd line

Answer 52

1. phagocyte engulfs pathogen and becomes APC 2. Helper T-cell binds to antigens on APC 3. phagocyte (APC) releases interleukin-1 4. Helper T-cells release interleukin-2 APC = antigen presenting cell (pathogen)

Question 53

3rd line cell mediated

Answer 53

1. phagocyte engulfs pathogen and becomes APC 2. Helper T-cell binds to antigens on APC 3. phagocyte (APC) releases interleukin-1 4. Helper T-cells release interleukin-2 5. growth and development of cytotoxic t-cells (killer t-cells) 6. killer t-cells bind to infected host cells and release perforin 7. perforin causes holes in membrane of infected cells 8. cell bursts and dies (apoptosis)

Question 54

3rd line humoral

Answer 54

1. phagocyte engulfs pathogen --> APC 2. Helper T-cell binds to antigens 3. phagocyte (APC) releases interleukin-1 4. Helper T-cells release interleukin-2 5. growth of b cells --> plasma & memory 6. plasma cells produce antibodies 7. antibodies bind to pathogens

Question 55

neutralisation?

Answer 55

3rd line humoral --> (step 7, antibodies bind to pathogen) antibodies bind to pathogen antigens and prevent penetration into host cells

Question 56

agglutination?

Answer 56

3rd line humoral --> (step 7) antibodies bind to pathogens 'glue', them together and reduce mobility

Question 57

what is cell mediated?

Answer 57

an immune response that does not involve antibodies

Question 58

complement system?

Answer 58

promotes inflammation, and attacks the pathogen's plasma membrane.