1. Blood

2. Blood is a fluid connective tissue that circulate through the cardiovascular system Conveying nutrients and oxygen to cells Carrying wastes and carbon dioxide away from cells Carrying hormones and other regulatory agents to and from the cells Having a major homeostatic role

4. BLOOD CONSISTS OF: FORMED PLASMA, 55% ELEMENTS, 45%which include: Red blood cellsWater White blood cells Proteins Blood platelesalbumin globulins fibrinogen Other solutes

6. Cells and platelets in circulating blood

7. Red blood cells (erythrocytes) Red blood cells constitute the largest number of cells in the blood (4,5-5,5 mln/mm cub) Red blood cells do not have a nucleus Red blood cells are specialized for the transport of oxygen and carbon dioxide by means of hemoglobin

9. White blood cells White blood cells are motile cells: they leave the circulation and migrate to their site of activity in the connective tissue Include: GRANULOCYTES AGRANULOCYTES Neutrophils Lymphocytes Eosinophils Monocytes Basophils

15. Blood platelets Plateles are membrane-bounded, enucleate cytoplasmic fragments of the resident cells of the red bone marrow - megacaryocytes Plateles function is blood clotting, clot retraction, and clot dissolution

17. Hemopoiesis

18. Origin of connective tissue & blood cells

19. Prenatal hemopoiesis Mesoblastic phase (2-6 weeks of gestation) – within the wall of the yolk sack (umbilical vesicle) Hepatic phase (6-38 weeks of gestation) – within the liver of embryo & fetus) Splenic phase (12-38 weeks of gestation) – within the spleen of embryo and fetus Myeloid phase (from 24 week of gestation through the rest of lifespan) – in the red bone marrow

20. Postnatal hemopoiesis (myeloid & lymphoid cell lines) Stem cells – Pluripotential hemopoietic stem cells (PHSC) – Multipotential hemopoietic stem cells (MHSC) (colony-forming units: CFU-GEMM + CFU-Ly) Progenitor cells – Unipotential cell lines (colony-forming units: CFU-E, CFU-Meg, CFU-Eo, CFU-Ba, CFU-GMo, CFU-LyT, CFU-LyB) Precursor cells

21. Precursor cells in the formation of erythrocytes and granulocytes