Introduction To Immunology

Question 1

What is meant by innate defence ?

Answer 1

First line of defence
Not improved by further exposure

Question 2

What is meant by adaptive defence ?

Answer 2

Second line of defence
Response adapts and improves with each exposure

Question 3

Specificity memory

Answer 3

Improved by further exposure

Question 4

Examples of 3 physical barriers

Answer 4

Skin, epithelia
Movement cilia
Trading mucus

Question 5

Examples of biochemical barriers (4)

Answer 5

Low pH sweat
Vaginal secretions
Stomach sectretions
Lysozyme in secretions (damages bacterial cell wall)

Question 6

Phagocytosis

Answer 6

Involves engulfing and destroying the pathogen
Lysosome fusion

Question 7

Opsonin

Answer 7

Substance that coats cell/bacteria and enhances the ability of phagocytes to phagocytose the particle.

Question 8

Opsonisation

Answer 8

Process of coating cell/bacteria with an opsonin

Question 9

Interferons function

Answer 9

Their main function is to interfere with the replication of the viruses within infected cells.

Interfere with viral proliferation

Question 10

When is interferon produced ?

Answer 10

When host cells become infected by a virus, they may produce interferons.

Question 11

What is cell lysis ?

Answer 11

Lysis is the breaking down of the membrane of a cell.

Question 12

What are the 3 things that destroy bacteria ?

Answer 12

Lysis
Phagocytes
Opsonisation

Question 13

What is involved in the secondary response ?

Answer 13

IgG

Question 14

What are plasma cells ?

Answer 14

Cells which produce antibodies

Question 15

Function of oestrogen in pregnancy

Answer 15

Stimulates IgA and IgG secretions which inhibit T cells which could reject the foetus.

Question 16

What are cytokines ?

Answer 16

Cytokines are signaling proteins that help control inflammation in your body.

They allow your immune system to mount a defense if germs or other substances that can make you sick enter your body.

Too many cytokines can lead to excess inflammation and conditions like autoimmune diseases.

Question 17

What are chemokines ?

Answer 17

They attract cells along a gradient of low to high chemical concentration

Question 18

Function of neutrophils

Answer 18

Neutrophil phagocytosis is activated by interaction with bacteria, either directly or after bacteria have been coated (opsonized) to make them more ingestible

Question 19

Function of eosinophils

Answer 19

Eosinophils release pro-inflammatory mediators to provide immunity against parasites.

Question 20

Where are mast cells found ?

Answer 20

Tissues (skin & mucosa)

Question 21

Function of mast cells and basophils

Answer 21

Both mast cells and basophils release pro-inflammatory mediators.

They play a role in allergy response

Question 22

Function of macrophages

Answer 22

A key role of tissue macrophages is the maintenance of tissue homeostasis through clearance of cellular debris, especially following infection or inflammation

Question 23

Dendritic cells function

Answer 23

The function of dendritic cells is activation of naive T lymphocytes to initiate adaptive immune responses.

These cells are like the spies. They notice if there is an invader and then present evidence of the invader to T cells in the lymph nodes.

Question 24

What is the function of antibodies ?

Answer 24

In host defence, antibodies target, neutralize and remove infectious organisms and toxins from the circulation and tissues, often through recruitment of innate host effector mechanisms such as complement, phagocytes and mast cells (by binding to specific surface receptors on these cells).

Question 25

Results of phagocyte defects

Answer 25

Cause deep skin infections, abscesses and osteomyelitis

Question 26

Results of defective antibodies

Answer 26

Producers experience infections with pyogenic (‘pus-forming’) bacteria

Question 27

Results of T lymphocyte deficiency

Answer 27

Causes infection with fungi, protozoa and intracellular microorganisms.

Question 28

Function of NK cells

Answer 28

Natural killer (NK) cells are effector lymphocytes of the innate immune system that control several types of tumors and microbial infections by limiting their spread and subsequent tissue damage.

Question 29

Function of T cells

Answer 29

T cells control your body’s immune system response and directly attack and kill infected cells and tumor cells.

Question 30

Function of B cells

Answer 30

B cells make antibodies. Antibodies are proteins that target viruses, bacteria and other foreign invaders.