Immunity & Disease

Question 1

What is the main role of the immune system?

Answer 1

To distinguish self from non-self molecules

Question 2

What are the two main pathways of the immune system?

Answer 2

Innate and adaptive

Question 3

What is innate immunity?

Answer 3

Non specific defences that are designed to prevent infections by viruses and bacteria. e.g. intact skin, mucus and cilia.

Question 4

What properties of the skin make it adaptive for innate immunity?

Answer 4

The outer layer of keratin acts as a mechanical barrier
Dead skin cells are constantly sloughed off making it harder for bacteria to colonise
Sweat and oils contain anti-microbial chemicals

Question 5

What properties of mucous membranes make it adaptive for innate immunity?

Answer 5

Normal flow of mucous washes bacteria and viruses off of mucous membranes
Cilia in the respiratory tract
Acid in the stomach and vagina
Enzymes in saliva and the eyes

Question 6

What 2 types of proteins act as chemical barriers in the innate immune system?

Answer 6

Complement and interferons

Question 7

What do interferon proteins in the innate immune system do?

Answer 7

They inhibit the replication of many viruses

Question 8

What are the 3 types of granulocytes?

Answer 8

Neutrophils, eosinophils and basophils

Question 9

What do granulocytes do?

Answer 9

Remove dead cells and micro organisms. They are attracted by an inflammatory response of damaged cells.

Question 10

Macrophages are in the category of…

Answer 10

Monocytes

Question 11

What are macrophages attracted to?

Answer 11

Different stimuli and usually arrive at sites of invasion later than granulocytes to stimulate specific immune responses

Question 12

Which proteins signals are released by macrophages?

Answer 12

Interleukin 1 and interleukin 6

Question 13

Why is fever a non specific response to infection?

Answer 13

To kill bacteria as bacteria grow in optimum temps below body temperature.

Question 14

How does pain, swelling and redness help in response to infection?

Answer 14

It increases capillary permeability, promotes blood flow and brings more phagocytic cells to the area

Question 15

What is the role of acute-phase proteins released from the liver?

Answer 15

They bind to bacteria and activate complement proteins

Question 16

What is adaptive immunity?

Answer 16

It is reliant on antigens (specific substances found in foreign microbes. It involves lymphocytes which travel swiftly around the body when in the blood or lymph

Question 17

Where are lymphocytes produced?

Answer 17

In the bone marrow

Question 18

Where do B cells mature?

Answer 18

In the bone marrow and then concentrate in the lymph nodes and spleen

Question 19

Where do T cells mature?

Answer 19

The thymus

Question 20

Circulation of B cells and T cells ensures…

Answer 20

That they come into contact with pathogens and each other

Question 21

What do T cells do?

Answer 21

Directly attack invaders (cytotoxic, CD8+ MHC I) for cell mediated immunity and recognise pathogens that have entered cells. They also help B cells

Question 22

What are the 2 types of T cells?

Answer 22

Cytotoxic and Helper

Question 23

What do cytotoxic T cells do?

Answer 23

Seek out and destroy any antigens in the system and destroy microbes tagged by antibodies
Some can recognise and destroy cancer cells

Question 24

What do helper T cells do?

Answer 24

Stimulate B cells and activate cytotoxic T cells and macrophages to attack infected cells

Question 25

How do T cells recognise an invader?

Answer 25

By detecting antigens on the cell surface

Question 26

Which cells do HIV destroy?

Answer 26

Helper T cells and CD4+, diminishing immune response

Question 27

What do B cells do?

Answer 27

Produce antibodies, cause agglutination, bind to antigens or become memory cells

Question 28

What are the causes of secondary immunodeficiency?

Answer 28

Malnutrition, burns, uremia, diabetes mellitus, immunotoxic medications, self medications of recreational drugs and alcohol & AIDS

Question 29

Type 1 diabetes mellitus, coeliac disease, multiple sclerosis, Hashimoto’s thyroiditis and rheumatoid arthritis are examples of…

Answer 29

Autoimmune diseases

Question 30

In what situations would we want to manipulate or suppress the immune system?

Answer 30

Organ transplants to prevent rejection
Immunotherapy for cancer
Vaccinations