lymphopoiesis.p vptx

ggf

1. monocytes

2. TECHNICAL UNIVERSITY OF MOMBASA FACULTY OF APPLIED AND HEALTH SCIENCES DEPARTMENT OF MEDICAL SCIENCES BACHELOR OF MEDICAL LABORATORY SCI.  UNIT CODE: AML 4206 UNIT NAME: HAEMATOLOGY 1 ASSIGNMENT: LYMPHOPOIESIS

3. FESTUS NGENO BMLS/027J/2014 OSUMBA PHELIX BMLS/037J/2014 FLORENCE KIIO BMLS/010J/2014 LECTURER: MR. RONALD WIGINA DATE: 08 TH MARCH 2016

4. MONOCYTES Monocytes are a type of white blood cell or leucocyte. They are the largest type of leucocyte and differentiate into macrophages, dendritic cells and foam cells. Monocytes influence the process of adaptive immunity. There are at least three types in human blood.

5. Monocytes are amoeboid in appearance and have a granulated cytoplasm containing nuclei. These are cells are one of the types of mononuclear leucocytes which shelter azurophil granules. The archetypal geometry of the monocyte nucleus is ellipsoidal, metaphorically bean shaped or kidney shaped .

6. Monocyte compose 2% to 10% of all leucocytes in the human body and has roles such as: Replenish resident macrophages, and move quickly in response to inflammation signals from sites of infection in the tissues. Divide or differentiate into macrophages or dendritic cells to effect an immune response. Monocytes are identified in stained smears by the large kidney shaped or notched nucleus

7. Monocytes under a light microscope from a peripheral blood smear surrounded by red blood cells.

8. PHYSIOLOGY Monocytes are produced in the bone marrow from precursors called monoblasts , bipotent cells that differentiated from hematopoietic stem cells. Circulate in the blood stream for 1-3 days and then typically move into tissues throughout the body. Half of them are stored as a reserve in the spleen in clusters in the red pulp`s Cord of Billroth . In the tissues monocytes mature into different types of macrophages at different anatomical locations.

9. Monocytes that migrate from blood stream to other tissues will then differentiate into tissue resident Macrophages or dendritic cells. Macrophages are responsible for protecting tissues from foreign substances, also suspected to be part of formation of important organs like heart and brain. Monocyte and their macrophages and dendritic-cell progeny functions by: Phagocytosis, antigen presentation and cytokine production .

10. MONOCYTE SUBPOPULATION There are at least three types of monocytes in human blood The classical monocyte: It’s characterized by high level of the CD14 cell surface receptor.   2.The non-classical shows low level expression of CD14 and additional co-expression of the CD16. 3.The intermediate monocyte with high level of expression of CD14 and low level expression of CD16.

11.     REFERENCES Kelley SL, Lukk T, Nair SK Journal of immunology Clinical hematology by Frank Firkin, Colin Chesterman , Bryan Rush. Fundermentals of immunology 5 th edition.