3.2.4.4 - Humoral Immunity

Question 1

What is meant by ‘humoral immunity’?

Answer 1

An immune response that involves the destruction of pathogens using antibodies.

Question 2

How many different types of B-lymphocytes exist in the body?

Answer 2

10 million (approx) - each one has different shaped receptors that bind to specific antigens.

Question 3

B-lymphocytes can develop into which type of cells after an immune response?

Answer 3

Plasma cells

Memory cells

Question 4

Plasma cells develop from B-lymphocytes. What is their function?

Answer 4

They produce antibodies to destroy pathogens.

Question 5

Memory cells can develop from B-lymphocytes. What is their function?

Answer 5

They are responsible for the secondary immune response.

If they encounter the same pathogen again they multiply rapidly and develop into plasma cells, which produce antibodies.

Question 6

Describe the process of humoral immunity.

Answer 6

1. Foreign antigen enters blood, initiating an immune response.
2. A specific B-lymphocyte engulfs forein antigen via endocytosis and presents foreign antigens on its cell surface membrane.
3. T_h cell binds to and stimulates specfic B-lymphocyte to undergo mitosis (clonal selection).
4. Cloned B-lymphocytes develop into plasma cells that produce monoclonal antibodies (primary response).
5. Some B-lymphocytes become memory cells that circulate blood ready to develop into plasma cells upon a recurring infection (secondary response).

Question 7

Describe how the presentation of a viral antigen leads to the secretion of antibody against viral antigens

Answer 7

T cells bind to the antigen (on APC)

T cells are activated in to T helper cells

T helper cells stimulate SPECIFIC B cells

B cells stimulated to divide by mitosis (clonal selection)

Forms plasma cells which release antibodies

Question 8

What makes all antibodies unqiue?

Answer 8

Specific tertiary structure

Variable region will ONLY bind/complementary to one antigen

only forms antigen-antibody specific complexes with specific antigens

Question 9

How is a secondary immune response different to a primary response

Answer 9

Secondary is

FASTER

GREATER concentration in antibodies produced

No LAG/Delay in antibody production

Question 10

How is passive immunity different to active immunity

Answer 10

Passive is

QUICKER

No MEMORY cells produced