immunology 2

Question 1

what are the 3 functions of the lymphatic system?

Answer 1

• drainage of tissue
• absorption and transport of fatty acids and fats
• immunity

Question 2

where does the thoracic duct drain into?

Answer 2

left subclavian vein

Question 3

recognition phase in the adaptive immune takes place in ‘secondary lymphoid organs’ what are these?

Answer 3

lymph nodes, the spleen, mucosal associated lymph tissue

Question 4

where do the lymphocytes originate and receive their early training?

Answer 4

primary lymphoid organs - bone marrow and thymus

Question 5

what is the function of the spleen

Answer 5

to filter blood

Question 6

what transports an antigen from the lumen of the intestine to the Peyer’s patch?

Answer 6

M cells

Question 7

in selecting T cells that can be used in our body what things must they be able to do?

Answer 7

• learn not to recognise ‘self’ antigens

- be restricted to recognised antigens in association with our MHC (major histocompatibility complex)

Question 8

What are CD4 and CD8 T cells?

Answer 8

CD4 - helper

CD8 - cytotoxic

Question 9

what are the steps of positive selection of T cells?

Answer 9

• T cells not expressing CD4, CD8 or TCR enter Thymus from bone marrow
• migrate to cortex and proliferate
• begin to express both CD4 and CD8 along with TCR
• presented with ‘self’ MHC on epithelial cells
• those that recognise it live and rest die

Question 10

What does MHC Class 1 do?

Answer 10

presents ‘virally induced’ peptides to CD8+ T cells and trigger cytotoxic response

Question 11

what does MHC Class II do?

Answer 11

presents exogenously produced Ag to CD4+ T cells and activates macrophages and B cells

Question 12

what do cytotoxic T cells release when exposed to infected/dysfunctional somatic cells?

Answer 12

perforin which forms pores in target cell

also release Granzyme B, a protease, tat can enter target cells via the pore and induce apoptosis