1. I MMUNE SYSTEM ORGANS & CELLS

2. I – S TEM OR M OTHER CELLS : It’s the place of the origin (Generation of lymphocytes) *found in the fetal liver during embryonal life. *then after birth → from bone marrow.

3. II- P RIMARY LYMPHOID ORGANS : (C ENTRAL LYMPHOID ORGAN ) Function … *maturation *education of the cellslymphocyte *differentiation Where the cells enter to grow, proliferate, mature, differentiate & transformed into the secondary lymphoid organ.

4. T HESE ORGANS ARE … Thymus → for T-lymphocytes. Bursa equivalent (In mammals), bursa fabracius (In birds). Bursa equivalent (bone marrow) in mammals & payer patches in cattle.

5. THYMUS GLAND 1 ST It is bi-lobe gland present on both sides in the esophagus in the entrance of esophagus cavity. In birds → it is 14 lobes It found from birth & continue to increase in size to full size at puberty, then decrease in size. The thymus consist of cortex & medulla. There is thymus barrier between the blood and the T cell unable to react with antigen. T- lymphocyte → called T cell because it’s maturation occurin thymus.

6. I N THIS THYMUS : The T cell maturation. education (Carry receptor called CD 4 & CD 8 ) Differentiation. T cytotoxic & T suppressor → carry CD 8 T helper → carry CD 4

7. 2 ND BURSA OF FABRICIUS Sac of lymphoid tissue present on cloaca present in birds. Responsible for maturation, education & differentiation of B-lymphocytes

8. 3 RD BURSA EQUIVALENT Group of tissues differ from mammals to another. In human, rodents → bone marrow. In cattle → payers patches

9. III-S ECONDARY LYMPHOID ORGANS :(P ERIPHERAL I.O).. Spleen, lymph nodes, tonsils, lymphoid organ (MALT). MALT → mucosal associated lymphoid tissue. 1. Spleen: Consist of white pulb & red pulb. For B cell in perarteriolosheath For T-Cell in white follicle. 2. Lymph node: It is consist of : cortex → housing of B-cell Paracortical area → housing T-Cell. Medulla → for another immune cells. 3. Tonsils 4. Malt Aggregates of lymphoid organ. e.g. BALT → baronchial associated lymphatic tissue. MALT → mucosal associated lymphatic tissue. GALT → gut associated lymphatic tissue.

10. 1ry lymphoid2ry lymphoid Other name Central L.T Peripheral L.T Function Maturation, education, differentiation Size Increase to size ↑ in to full size puberty The small size on life RemovalAfter the immunity Not affect the puberty Reaction to antigen Can’t react with AgReact with Antigen

11. C ELL OF IMMUNE SYSTEM 1- Lymphocytes B cellsT cells OriginB.M, liver of fetusB.M., liver of fetus Maturation education Bursa of fabricius bursa equivalent (B.M., players patches) Thymus StorageSpleen, (Periaertiolar tonsils, cortex) lymph node, MALT. Spleen (white follicle), tonsils (Paracortical area) L.node, MALT

12. C ONTINUE …. TypesOne 1 type Th → T helper, help both humeral and cell mediated immunity (Carry CD 4 ) Tc → T cytotoxic Ts → T suppress of immune system after complete Ag destructiare. Cells products (Secretions) Bcel differentiate to plasma cell & memory cells. Plasma cell: secret Antibody Active Tc release certain enzymes called lymphokine.

13. C ONTINUE …. Lymphocytes transformation Yes to plasma cell Yes to small lymphocytes Life spaneShortLong Receptor 1.For AgBCRTCR 2. E-rosette formation (receptor to sheep RBC) NoYes 3. C3b for complementYesNo 4. Carry MHC MHCI &MHCII because it is Apc MHCI 5. Other receptorCD 19, CD 21 CD 3 Th → CD 4 Tc & Ts → CD 8 CD 2 & CD 58

14. C ELLS THAT LINK IN INNATE & ADAPTIVE IMMUNITY (APC).. Antigen Presenting Cells: A) Dendritic cell: It is cell found in epithelial tissue. It is APC & act also as phagocytic cell as m.ø. What is APC doing? APC → Carry to Ag on MHCII, this antigen is exogenous Ag- & present it to Th. T helper carry CD4 for MHCII or carry Ag direct to B cells. N B APC → carry the antigen after engulfment, fragmentation to different epitopes. Then epitope exposed on surfaces of APC with MHCII.

15. B) Macrophage: as (A) C) B cells: Act as APC in the 2ry immune response Can be activated directly by exogenous antigen but fully activated by T-helper cell which secret factors → help B-cell to be fully activated.

16. R ECEPTORS OR M ARKERS OF T & B CELL 1) Ag binding receptors → BCR, TCR BCR (B cell receptor)  2 class of immunoglobulin (IgM and IgD)  There are 200,000- 500,000  Bivalent  Specified TCR (T cell receptor)  2 polypeptide (α, β)  100,000 copy  Is less  Not specified

17. 2) O THER RECEPTOR ON T CELL CD 2 & CD 58 → Bind m.ø. CD 3 → To amplify signals. CD 4 on Th → for MHCII. CD 8 on Tc & Ts → for MHCI.

18. 3) M AJOR HISTO - COMPATIBILITY COMPLEX Group of surface receptor. MHCI: On an nucleated cells, carry endogenous antigenous for T cytotoxic & T suppressor. MHCII: on APC (m.ø. B cells & dendritic cells) Carry exogenous Ag. To T helper and B cells

19. 4) R ECEPTOR FOR REGULATOR THE FUNCTION OF T & B CELLS For complement For cytokine For antibody 5) R ECEPTOR FOR UNKNOWN FUNCTION.

20. THANK YOU