IMM - Lymphoid tissue

Question 1

Lymphatic system

Answer 1

Made of lymphatic vessels and secondary lymphoid tissue

Question 2

Lymphoid tissue

Answer 2

Primary/secondary/tertiary

Question 3

Primary lymphoid tissue

Answer 3

Where lymphocytes (B/T/NK) are produced - lymphopoieses

Question 4

Primary lymphoid organs

Answer 4

Bone marrow/thymus/foetal liver (8-10 weeks after gestatio?)

Question 5

B and T cells

Answer 5

Comprise adaptive immune response which is SPECIFIC (range of unique T/B receptors) - builds immunological memory

Question 6

Infection

Answer 6

White cell production increases

Question 7

In children

Answer 7

Haematopoiesis in foetus - liver is primary organ for this (ALL bones)

Question 8

Adults

Answer 8

Bone marrow production in vertebrae/ribs

Question 9

T cell terminal differentiation

Answer 9

They migrate from bone marrow site into thymus

Question 10

Which bone marrow produces blood cells?

Answer 10

RED bone marrow

Question 11

Repertoire

Answer 11

Range of genetically different BCRs or TCRs present in a given host ; greater the repertoire more diverse can recognise a greater variety of threats

Question 12

B cell repertoire

Answer 12

Made in bone marrow - final maturation in periphery

Question 13

What type of T cells move from bone marrow to thymus?

Answer 13

Immature - thymocytes

Question 14

T cell selection

Answer 14

Positive selection - does it recognise antigens via their TCR - can the TCR signal
Negative selection - does it react against out own body and get very activated to self antigens

Question 15

Thymus cortex/medulla

Answer 15

Medulla below cortex ; medulla is lighter than cortex

Question 16

Thymus decline?

Answer 16

With age - shining/reduction in mass ; thymic involution reduced output of T cells

Question 17

T cell vs t cell repertoire

Answer 17

3.75*10^11 t cells
TCR repertoire ; genes allow for between 10^15/10^20 - how does small pop of cells find a antigen in the body

Question 18

Secondary lymphoid tissues

Answer 18

Where lymphocytes can interact with antigens and other lymphocytes

Question 19

Secondary lymphoid organs

Answer 19

Lymph nodes
Tonsils
Spleen
Appendix
Mucosal associated tissue

Question 20

How are lymphoid tissue distributed

Answer 20

Interconnected via lymphatic system and blood

Question 21

Discrete organs

Answer 21

Lymph nodes/adenoids
(or can be part of an organ like the spleen for example)

Question 22

Lymph node structure

Answer 22

Look at pic
Afferent lymphatic vessel and efferent so the lymph fluid is drained (not blood via arterial/venous connection)

Question 23

Germinal centre

Answer 23

B cells undergo rearrangement so they are better at secreting antibodies

Question 24

On the outside lymph nodes

Answer 24

Lymphoid follices (b cell area)

Question 25

Inside area (after yellow circles of germinal centre)

Answer 25

t cell area

Question 26

Spleen

Answer 26

Filters blood for antigens (only the red pulp part of the spleen)

Question 27

Gut associated lymphoid tissue

Answer 27

Specialised tissue called Peyer's patches and found below epithelium of the ileum of the small intestine ; follicle highly enriched with germinal centres - home to largest community of microbiota

Question 28

Tonsils

Answer 28

Oral antigens are detected - forms the waldeyer ring

Question 29

Where are SLO particularly located?

Answer 29

Barrier surfaces like the lungs/skin/GI tract

Question 30

Lymphatic network

Answer 30

Lymphatics drain fluid from around the body and bring large volume of molecules through SLO

Question 31

Purpose of lymphatic network

Answer 31

Immune cells including lymphocytes and antigen bearing dendritic cells to migrate to and from sites of inflammation to lymph nodes

Question 32

B/T cells

Answer 32

Constantly recirculate round every 24 hours rather than just being static in the SLO

Question 33

When inflammation

Answer 33

Lymph nodes closest to site of inflammation will send out signals to retain B/T cells