Lymphoid Tissues

Question 1

What are primary lymphoid tissues?

Answer 1

Organs that produce lymphocytes (e.g. B cells, T cells, Natural Killer cells) - lymphopoiesis : thymus, bone marrow, foetal liver

Question 2

Adaptive immune response comprised of?

Answer 2

B and T cells

Question 3

After birth

Answer 3

Bone marrow very cellular - increase in white cell production
Age = bone marrow replaced by fat so restricted lymphocyte production

Question 4

Increased lymphoeisis

Answer 4

After infection / inflammation

Question 5

Progenitor

Answer 5

To nk, b or T cell

Or dendritic

Question 6

Repertoires definition

Answer 6

Range of cells

Question 7

Thymus

Answer 7

Fatty lymphoid tissue on top of heart

Question 8

Stepwise defferentiation

Answer 8

Positive Cells deleted when combining genes to produce new receptors goes wrong - nonfunctional
Negative - if it does; it’s removed

Double positive

Question 9

Age?

Answer 9

Thymus gets smaller AND becomes fatty thymus embolition (double check)
Ability to generate new T cells declines as we age

Question 10

What are secondary lymphoid tissues?

Answer 10

Spleen
Lymph nodes
Appendix
Mucosal associate

Question 11

What is the issue with huge T cell / B cell reservoirs?

Answer 11

Many T cells but only one of them can recognise a specific antigen (lost in the entire body)
2nd lymphoid tissue must find a way to get that specific cell to interact with the …

Question 12

Distribute lymphoid tissue all Dover the body

Answer 12

Lymphocyte can circle around any possible common point of threat

Question 13

Lymph nodes

Answer 13

Discrete organs - distinct tissues that can be felt

Or regions of larger tissues (some part of the spleen)

Question 14

Fibrotic reticular cell - recruiting T cells

Answer 14

Look it up

Question 15

Different zones in the lymph nodes

Answer 15

T cell zone

B cell zone

Question 16

Spleen

Answer 16

Distinct t and B cell zones
Spleen = Site for antigen screening
Red and white pulp - organised into distinct t and B cell follicles

Question 17

Epithelial barriers

Answer 17

Physical barrier skin + different tracts

Connected to lymphoid tissues

Question 18

Below epithelium of the ileum

Answer 18

Receives anthems directly from draining lymph or sample via m cells / dendritic cells

Question 19

Why there are so many active B cells in our gut?

Answer 19

Ingest many pathogens = major source of infection
More bacteria in our guts than cells in our body
Permanent source of foreign antigens
Immune system responds by secreting Abs

Question 20

Tonsils

Answer 20

Continuous exposure to oral antigens

Microbes living on top of epithelial layer