T Lymphocytes

Question 1

When are lymphocytes used

Answer 1

They are used in a specific immune response

Question 2

What are the 3 types of antigen presenting cell

Answer 2

A phagocyte which has engulfed a pathogen
A cancer cell
A body cell invaded by a pathogen

Question 3

What do the 3 types of APCs have in common

Answer 3

In all of them, the antigens present on the outside of the cell

Question 4

Define antigen

Answer 4

A foreign protein which triggers an immune response

Question 5

What type of immunity do T lymphocytes have? What does this do?

Answer 5

Cell mediated immunity
They can detect the antigens on the surface of antigen presenting cells

Question 6

Describe the role of T lymphocytes in a specific immune response

Answer 6

Specific helper T cells with complementary receptors bind to the antigen on the APC
This stimulates other T cells to:
- Stimulate B cells to divide and produce antibodies
- Stimulate phagocytes to engulf pathogens promoting a non specific response
- Divide in to cytotoxic T cells which cause holes to be made in the cell membrane meaning cells become more permeable to substances

Question 7

What happens in the immune response when B cells divide

Answer 7

The B cells produce antibodies

Question 8

What happens in the immune response when the phagocytes are stimulated

Answer 8

Pathogens are engulfed in phagocytosis which promotes a non specific response

Question 9

What happens in the immune response when the T cells divide into cytotoxic T cells

Answer 9

The killer T cells cause holes to be made in the cell membrane meaning cells become more permeable to substances