B Cells And Humoral Response

Question 1

What is the humoral response

Answer 1

The response which involves antibodies which are soluble and travel in body fluids. The old fashioned word for body fluid is humour, hence the name

Question 2

What are the first 3 steps of the humoral response: clonal selection

Answer 2

1: b lymphocytes have antibodies on their surface
2: when they encounter the complementary antigen (attached to a pathogen) the antibody attaches to the antigen and the b lymphocyte engulfs it, becoming an apc
3: t helper cell binds to the antigen on the surface of the b lymphocyte and causes the b lymphocyte to divide by mitosis, forming clones of the b lymphocyte

Question 3

What happens after clonal selection

Answer 3

The clones develop into plasma cells or memory cells

Question 4

What do plasma cells do

Answer 4

Secrete antibodies into the blood plasma

Question 5

What do memory cells do

Answer 5

They circulate in the blood or tissue fluid and if they encounter the same antigen, they produce the secondary immune response, dividing rapidly and producing many of the complementary antibodies. Giving long term immunity

Question 6

What is the primary immune response: first exposure

Answer 6

This is the first time the body comes across pathogens, there are no memory cells yet formed
After the first exposure there is a time delay due to clonal selection and expansion of b and t lymphocytes
and the synthesis of antibodies
During this time we likely feel unwell

Question 7

What is the secondary immune response: second exposure

Answer 7

Memory cells have formed
The t and b memory cells recognise the antigens and react much quicker, producing more antibodies in a shorter time
You don’t feel unwell