1. Chapter Immune system

2. 1. Components
1)      Cells

3. ① Lymphocyte: a. T-lymphocytes:
cytotoxic T cell: Tc C- kill the tumor cell, virus infective cell and foreign cell
helper T cell: Th C- promotes activity of BLC and Tc C
suppressor T cell: Ts C –regulate the function of BLC and TC
b. B-lymphocytes: become into plasma cell
c. NK cell: counteract virus infective cell and tumor cell

4. ②Plasma cell
③antigen presenting cell:
a. dendritic cell:
Blood DC
Langerhans cell
interstitial cell
veiled cell
interdigitating cell
b.macrophage: mononuclear phagocytic system

5. ④other cells:
granulated cell
mast cell
blood platelet
blood-borne stem cell
*Function:
i.      immunologic defence function
ii.     immune surveillance function
iii.    immune homeostasis

6. 2)     Lymphoid tissue
---reticular T:
reticular cell: stellate-shaped with processes to form network
reticular fiber
---lymphocytes, macrophage, plasma cell and mast cell

7. a. Diffuse LT:
no clear boundary
mainly consists of TLC
postcapillary venules:
-high endothelial venules
-opening for LC enter LT from blood

8. b. Lymphoid nodule:
spherical or ovoid
have clear boundaries
mainly composed of BLC
germinal center: stained pale
* primary LN → secondary LN

9. 3) Lymphoid organs
a. Central lymphoid organs: thymus, bone marrow
developed earlier
blood-borne stem cell comes from yolk sac
microenvironment → proliferation
promoting
send LC to PLD and LT two weeks before borne

10. b. Peripheral lymphoid organs: lymph node, spleen and palatine tonsil
developed later
LC come from CLO
cell proliferation need antigen stimulating- antigen dependent
place for immune reactions

11. 2.thymus Structure of thymus ---capsule: CT→interlobular septum
---cortex: dark-staining
---medulla: lighter-staining
---consists of thymic epithelial cell, thymic stromal cell( ma, eo,mc, fibroblast and myoid cell) and thymocytes

12. ①cortex:
---thymic epithelial cell(epithelial reticular cell):
subcapsular epithelial cell:
/flattened
/secret β 2-microglobulin, thymosin and thymopoietin
interdigitation dendritic cell:
/more processes
/MHC antigen
---thymocyte: different stages of LC
large LC( prethymocyte): superfacial cortex
common thymocyte: deep cortex %

13. 2) medulla:
---epithelial reticular cell
medullary epithelial cell: secret thymosin
thymic corpuscle epithelial cell
* thymic corpuscle:
/spherical or ovoid, 30-50um in D
/concentrically-arranged epithelial reticular cells
/peripheral cell: inmature
/near centra: mature
/center cell: keratinased-eosinophilic, hyalinised, with invading of macrophage, eosinophil and LC
/function: unknown
---thymocyte, macrophage

14. 3) Blood-thymus barrier:
---Components
Contineous endothelial cell
Complete basement membrane of endothelium
peri-vessel space containing macrophage
basal lamina of epithelial reticular cell
Processes of epithelial reticular cell
---Function: provide a stable environment for lymphocytes development

15. 4) function:
a. Place for mature and differentiation of TLC
b. Immune regulation

16. 3. Lymph node ---widely distributed ---in groups
---ovoid or kidney-shaped with hilum
---afferent and efferent lymphatic vessel

17. 1) Structure
---capsule: CT, trabeculae or septa
---cortex: outer densely-stained part
---medulla: inner paler-stained part

18. ①Cortex: a. superfacial cortex: ---lymphoid N:
BLC, Macrophage, FDC, Th
primary LN → secondary LN
*germinal center: central pale area
/dark zone: large, immature BLC, Th
/light zone: medium-sized BLC, Th C, macrophage, FDC
/cap: small BLC: mature←supermutation
---diffuse LT: thin layer

20. FDC: (follicular dendritic cell)
light zone
no expression of MHC-II molecules (major histocompatibility complexes)
have Fc receptor and C3 receptor: collect the antigen-antibody complexes and transfer them to BLC and Th C
function:
i. active the BLC
ii. regulate the synthesis of antibody

21. b.Paracortex zone-deep cortex unit
---diffuse LT:
TLC, Marcophage, Th cell
interdigitating cell: DC cell
-more processes
-N: irregular
-less organelle
-express MHC-II
postcapillary venules:
-thick endothelial cell
-LC within the wall
-opening for LC enter LN

23. c. Cortical sinus ---subcapsular sinus: afferent LV enter
---peritrabecular sinus
---structure:
endothelium
RF and RC
cavity:
-endothelial cell: stellate for support
-macrophage: filter lymph
-veiled cell: Langerhans cell ( phagocytose antigen) → efferent LV → LN → paracortex zone

25. ②Medulla
---medullary cord: LT cord:
/BLC, plasma cell, macrophage, mast cell
/postcapillary venules: channel
---medullary sinus:
/similar to cortical sinus and connect with C S
/more macrophage

26. ③Passage of Lymph in LN
afferent LV →subcapsular sinuses→peritrabecular sinuses→(narrow channel) →medullary sinus→efferent LV

27. 3)      Functions:
a.Filter the lymph
b.Place to give rise to the immune response
c. Involve in the recirculation of LC
*Recirculation of LC:
LC(blood) →(postcapillary venules) → LN → medulla → efferent LV → Blood →LN artery → postcapillary venules →LN
Time: 24-48h

28. 4. Spleen
1) Structure
---capsule: thick DCT with SM and mesothelium, also form trabeculae
---white pulp
---marginal zone
---red pulp

29. ① White pulp: 1-2mm gray-white spots periarterial lymphatic sheath:
-central artery
-diffuse LT : TLC, macrophage, interdigitating cell
splenic corpuscle:
-BLC, macrophage, FDC
-lymphoid nodules

30. ② Marginal zone:
100um width
TLC, BLC, macrophage, less erythrocyte
marginal sinus: central artery’s branch- channel for antigen and LC enter LT
place: capture recognize and induce immune reaction

31. ③ Red pulp: constitute about 2/3 of splenic volume
a. splenic cord:
LT cord
BLC, DC. M, TC , erythrocytes
place: filter blood
b. splenic sinus:
Blood sinus; 12-14um
endothelial cell: rod-liked, gap RT
basal lamina: incomplete
M-more

33. 2) Blood supply of spleen
splenic A→trabecular A→central A branches → marginal sinuses
penicillar Arterioles(including: pulp arteriole→ sheathed capillary→ arterial capillary) → splenic sinus→ pulp venule→ trabecular vein→ splenic vein

34. 3) Function:
a. filter the blood
b. immune reaction
c. production of blood in fetus
d. blood storage: 40 ml

35. 5. tonsil
---palatine tonsil
---pharyngeal tonsil
---lingual tonsil

36. palatine:
---structure:
Stratified squamous epi: invaginated to form many crypts
Epithelium of crypt contain LC, PC, Ma and Langerhans cell
Space and channel between epi.cell: opening to crypt epi. surface, LC filling the channel- lymphoepithelial tissue
Lamina propria: Diffuse LT and LN