General Immunology

Question 1

What two broad categories is the immune system divided into?

Answer 1

Innate and Adaptive

Question 2

What’s the difference between innate and adaptive immunity?

Answer 2

Innate – quick response, first line of defence

Adaptive – delayed response, second line of defence

NB. these two systems work together

Question 3

What are the key players of the innate immune system? (5)

Answer 3

Macrophages

Dendritic cells

Mast cells

Complement proteins

Inflammatory mediators (chemical)

Question 4

Which cells initiate the adaptive immune system?

Answer 4

T-Cells

Question 5

What are the key players of the adaptive immune system?

Answer 5

T-Cells

B-Cells.

(+ Memory cells)

Question 6

What do B-cells secrete?

Answer 6

Antibodies

Question 7

What do T-Cells differentiate into?

Answer 7

T-Killer cells

T-Helper cells

Question 8

When an antibody combines with an antigen it can be eliminated by which cells?

Answer 8

Phagocytes

Question 9

What are the two main divisions of the adaptive immune system?

Answer 9

Humoral (B-Cells)

Cell-mediated (T-Cells)

NB. These two divisions work together to destroy pathogens.

Question 10

What is the job of phagocytes?

Answer 10

Innate immunity, first line of defence. Engulf and consume pathogen.

Question 11

What happens if the phagocytes can’t destroy the pathogen?

Answer 11

The pathogen is presented (by the phagocytes) to the adaptive immunity.

Question 12

What do T-Cells differentiate into?

Answer 12

Killer T-Cells

Helper T-Cells

Question 13

T-Helper Cells activate ……….. to secrete ………

Answer 13

B-cells, antibodies

Question 14

Naïve T Cells, and Naïve B-Cells originate from which cell?

Answer 14

Progenitor Lymphoid Cell

Question 15

How do naïve T Cells become activated?

Answer 15

When they are presented with an infected phagocyte within an antigen MHC (major histocompatibility complex) Class I

Question 16

Once activated, naïve T Cells become……

Answer 16

Cytotoxic T Cells (these kill infected cells)

Question 17

What is the job of T-Helper Cells? (3)

Answer 17

Enhance immune response by:

Activating B-Cells

Acivating NK (natural Killer) Cells

Activating macrophages

Question 18

What do naïve B-Cells have? (derived from progenitor lymphoid cells)

Answer 18

Antibodies

Question 19

What type of cells are used for 2nd exposure of an antigen?

Answer 19

Memory B Cells

Question 20

What are opsonins?

Answer 20

They are antibodies that bind with antigens to act as markers so that phagocytes can recognise foreign cells and destroy them.

Question 21

What does ‘humoral’ mean?

Answer 21

‘of or related to body fluids’

Question 22

What is an antibody?

Answer 22

It’s a type of globular protein that reacts with a specitic antigen

Question 23

What are the three different types of antibodies?

Answer 23

Opsonins

Agglutinins

Lysins

Question 24

Antibodies are produced by which type of lymphocyte?

Answer 24

B Cells (or B Lymphocytes)

Question 25

What type of cells to B Cells produce after encountering an antigen for the first time? (2)

Answer 25

Memory Cells Plasma Cells

Question 26

The humoral response of adaptive immunity uses......

Answer 26

soluble antibodies in the blood and lymph

Question 27

What is Cell-mediated response (part of adaptive immunity)

Answer 27

**_Cells_** rather than antibodies are produced which are specific to the antigens on the invading pathogens.

Question 28

Where do T Cells mature?

Answer 28

Thymus

Question 29

What cell is used in Cell-mediated response?

Answer 29

T Cells (type of lymphocyte) | (especially **helper T cells**)

Question 30

What happens when a helper T Cell meets an antigen? (2)

Answer 30

It divides mitotically. Some of the divided cells remain in the blood and lymph as **memory cells.** Other cells **activate** other cells in the immune system.

Question 31

What cells do helper T cells activate in the immune system? (4)

Answer 31

macrophages (large phagocytotic wbc) killer T Cells Suppressor T Cells also.. **they activate B cells**, therefore humoral and cell-mediated responses work together

Question 32

What is the function of suppressor T cells?

Answer 32

general regulation of the immune system by 'switching off' or suppressing immune responses when appropriate.

Question 33

What are cytokines?

Answer 33

small protein molecules. **Activators and inhibitors** of **cell signalling pathways** for growth, differentiation and behaviour of cells within the immune system. **Interferons** are a group of cytokines.

Question 34

Where do T-Cell precursors migrate to?

Answer 34

Thymus

Question 35

Where do immature B-Cell migrate to?

Answer 35

Lymph nodes (but they have to wait for a signal before they become activated)

Question 36

Where are leukocytes made?

Answer 36

Bood marrow – as stem cells

Question 37

Where do the granulocytes migrate to (after being produced in the bone marrow)?

Answer 37

They circulate in the blood stream

Question 38

What are the granulocytes?

Answer 38

Basophils Eosinophils Neutrophils Mast cells (they circulate around the blood stream)

Question 39

Where are complement proteins produced?

Answer 39

In the Liver (secreted into the bloodstream in an inactive form)

Question 40

What kind of cells will migrate into the tissues (generally)

Answer 40

Cells of the innate immune system

Question 41

What is the name of circulating macrophages in the blood stream?

Answer 41

Monocyte

Question 42

The process of migration of cells from the bloodstream towards the site of infection in the tissues is called….

Answer 42

Diapedesis

Question 43

What does the lymphatic system do?

Answer 43

It transports active T Cells and B Cells around the body. NB. There maybe inactive B-Cells in the blood stream. They have to go to the lymph nodes for activation.

Question 44

Lymphoid precursors circulate in the blood stream and then go to the ….. to become …….

Answer 44

Thymus T-Cells

Question 45

Define inflammation

Answer 45

The sum of the host's defences to infectious or noxious stimuli

Question 46

What is the point of inflammation?

Answer 46

* to bring defence cells to the area * inactive/ destroy invaders * begin repair

Question 47

If there is no infection, what do you find in lymph nodes?

Answer 47

Naive B Cells Naive T Cells

Question 48

What are the two types of inflammatory mediators?

Answer 48

1. Plasma inflammatory mediators (made by the liver); complement proteins and kinins 2. Cell-derived inflammatory mediators (derived from the cells)

Question 49

What are immunoglobulins?

Answer 49

**glycoproteins** on cell surface membranes of B cells. When B cell meets an antigen is produces \>\> immunoglobulins which when in the blood, act as **antibodies**.

Question 50

Where does the signal come from for B cells to start producing lots of immunoglobulins (antibodies)?

Answer 50

NOT from the antigen. Signal comes from helper T cells that are specific to the same antigen.

Question 51

When activated, B cells divide rapidly by ............ to produce ........... cells

Answer 51

mitosis plasma

Question 52

What do plasma cells do?

Answer 52

Produce lots of antibodies after activation of B cell by helper T cell.

Question 53

What is clonal selection?

Answer 53

The process by which a particular antigen promotes the production of a specific antibody.