Defense and disease

Question 1

Immunity?

Answer 1

Collective term for all organism’s defense mechanisms

Question 2

Components of immune system and functions.

Answer 2

Bone marrow - Produce red blood cells
Thymus gland - aids maturation of T-lymphocytes
Lymph nodes - Contain macrophages and lymphocytes
Spleen - Filters debris from blood.

Question 3

Features of innate immunity? (your default immune system)

Answer 3

non-specific
from birth
first line of defence
rapid response
- Activates acquired immune system through cell signalling.

Question 4

Pathogen barriers?

Answer 4

Tears, mucus, sweat, fur

Question 5

Examples of innate immunity?

Answer 5

Inflamatory response, fever

Question 6

What do macrophages circulate in?

Answer 6

extracellular fluid

Question 7

What are macrophages?

Answer 7

Antigen presenting cell for T cell to detect.

Question 8

What happens to neutrofils?

Answer 8

Released to kill other bacteria in localised area.

Question 9

Recall process of phagocytosis!

Answer 9

Yeah…thumbs up

Question 10

What do natural killer cells do?

Answer 10

Target viral host cells

1. Recognises cells that have lost surface glycoproteins - MHC-1.
2. Create hole in infected cells plasma membrane.
3. Water enters cell via osmosis and the cell bursts.

Question 11

What cells do NK cells also target?

Answer 11

Cancerous cells.

Question 12

What’s the inflammatory response?

Answer 12

Innate immune response used a lot in wild animals.

Question 13

Process of a fever?

Answer 13

• Macrophage phagocytes a microbe and secretes intrleukin-1.
• Interleukin-1 travels in bloodstream to brain.
• Brain raises core body temperature in response - Fever.

Question 14

What do antibodies do?

Answer 14

Bind to pathogens and self cells.

Recognise specific antigens they are complimentary to.

Question 15

Antibody structure?

Answer 15

4 polypeptides - 2 light chains/ 2 heavy chains.
Antigen binding site is the variable region
variable and non variable regions
chains held together by disulphide bonds.

Question 16

What can antibodies also be called

Answer 16

immunoglobins

Question 17

Classes of antibodies?

Answer 17

IgB, IgE, IgD, IgM, IgA

Remember IgBEDMA

Question 18

Features of Aquired immunity

Answer 18

• Specific
• Slow response
• Called adaptive immunity (not born with it).

Question 19

Types of acquired immunity?

Answer 19

Active-Natural-Clinical disease (having disease), subclinical infection (Having infection).
Active-Artificial-Vaccine, toxoid.
Passive-Natural-From mother (inherited)
Passive-Artificial-immunoglobins (from vaccines)

Question 20

Why are lymphocytes critical to specific immune response?

Answer 20

• Produced in bone marrow
• Circulate in blood and lymphatic system
• B lymphocytes/ T lymphocytes.

Question 21

Process of T-cell mediated immunity?

Answer 21

1. Macrophage presents complimentary viral antigen on its cell surface membrane via MHC-II protein.
2. T helper cell has a receptor complimentary to viral antigen and so it takes viral antigen.
3. At same time antigen -presenting cell uses MHC-I protein to provide viral antigen to cytotoxic T cell with a complimentary receptor.
4. Proliferation - helper T cell gives interlukin-2 to cytotoxic T cell.
5. Cytotoxic T-cell binds to an infected cell and destroys it as it’s complimentary.

Question 22

Process of B-cell immunity?

Answer 22

1. Invading microbes are binded to by B cell receptors (antibodies).
2. At same time macrophage processes antigen from microbe by MHC-II protein and transfers antigen to complimentary T cell receptor on helper T cell.
3. Helper T cell transfers processed antigen to complimentary receptor on a B cell.
4. Clonal selection - B cell divides by mitosis into plasma cells that secrete monoclonal antibodies specific to original microbe.
5. Antibodies bind to microbes and mark them as destructible.
6. Same plasma cells divide into memory cells that record pathogen’s antigen for next time. So in future invasion it can divide into plasma cells with monoclonal antibodies specific to that pathogen.

Question 23

What do vaccines do and why?

Answer 23

-Produces same effect as active immunity without true exposure to the real pathogen.
-Therefore the recipient of the vaccination does not become ill from the disease
.- Can provide life long protection via memory B cells.

Question 24

What are the issues with vaccines?

Answer 24

Risky - Development expensive and not 100% successful
Needs a consumer market
Disease eradication badly effects business
Not a vaccine for every infectious disease.
Pathogens mutate and evolve - past vaccines stop working so need replacement.

Question 25

How does herd immunity work?

Answer 25

• No one immune - Contagious disease spreads through population.
• Some population immunised - contagious disease spreads through some of population.
• Most of population immunised - spreads of contagious disease is contained.

Question 26

How do Allergic reactions work?

Answer 26

1. Allergen contacts B cell.
2. Divides into plasma cell that release IgE antibodies.
3. Mast cell has IgE receptors.
4. Mast cells IgE receptors bind to allergens which triggers histomines to be released by Mast cell as an allergic reaction.

Question 27

What’s the autoimmune response?

Answer 27

Body fails to detect self cell and attacks it.

Question 28

Features of Immunodeficiency?

Answer 28

• Primary or secondary depending on if it occurs In infancy or birth.
• Disorders include protein deficiencies - HIV infection, removal of spleen.