Blood and lymph Hematopoiesis

1. Blood components and functions

2. Plasma

3. Erythrocytes

4. Leucocytes

5. Theories of hematopoiesis

6. Stem cell structure and functions

7. Embryonic and postembryonic hematopoiesis

8. Classes of hematopoietic cells

9. Main features of different hematopoietic lines

Tissues of inner environment

1. Blood and lymph 2. Connective tissues

Blood functionsTransport

1. Trophic

2. Respiration

3. Humoral

4. Excretion

Protective

Homeostatic

Blood= cells + plasma (RBC+WBC+PL)

hematocrit VFe/Vpl

Plasma

physical condition – colloid solution

chemical composition: 90-93 % water

7-10 % dry residue (7% proteins; albumins 4%, globulins 1-3%, fibrinogen 0,2-0,4%)

others 3% (enzymes, vitamins, salts, waste products…)

pH 7,36

Hemogram (general blood analysis)

Hematocrit 45:55

Erythrocytes men 3,9-5,5 x 10 12/l

women 3,7-4,9 x 10 12/l

Reticulocytes 2-10 per 1000 erythrocytes

Hemoglobin men 130-160 g/l

women 120-140 g/l

Leucocytes 4-9 x 10 9/l

Platelets 180-320 x 10 9/l

Speed of blood sedimentation men

6-12 mm/hour

women 2-14 mm/hour

ErythrocytesRespiratoryTransportAlkaline-acidic balanceGroup

Sickle-cellanemia

Discocytes, planocytes,echinocytes…

Anisocytosis >20% abnormalshaped

cells

Normocyte 7,1-7,9 mkm (75%)

Macrocyte >8 mkm

Microcyte <6 mkm

Poykilocytosis >25% abnormalsized cells

Leucocytes

Leucocytes count %

Granulocytes Agranulocytes

Bazophilic

Eosinophilic

Neutrophilic Lym-pho-cytes

Monocytes

Band Juve-nile

Segmen-ted

0-1 0.5-5 0.5-1

1-6 47-72 19-37 3-11

Neutrophils

Neutrophil

Eosinophil

Eosinophil

Basophil

Basophil

Lymphocytes –immunocytes

1. Small, medium sized, large

2. EM: small light and dark, medium sized, B-plasma cells

3. T and B

4. Active and memory cells

Lymphocyte

Monocyte-mononuclear cell>20 mkmBean-like nucleusGolgi apparatus =>lysosomesActive type - macrophage

Monocyte

Platelet

HEMATOPOIESIS –blood components development

(blood cells and plasma)

Hematocytopoiesis:

1. Erythrocytopoiesis

2. Leucocytopoiesis

a) granulocytopoiesis

b) agranulocytopoiesis

3.Trombocytopoiesis

THEORIES OF HEMATOPOIESIS

• POLYPHYLETIC THEORY – each mature blood cell type is derived from its own distinct stem cell

• MONOPHYLETIC THEORY (A.A. Maximov) – there is one stem cell, which can form all the mature blood cells types

• Multipotential stem cell (CFU-S – colony-forming-unit of spleen)

Scheme of hematopoiesis

Hematopoietic stem cell

1. Originates in the yolk sac

2. Thrives in RBM

3. Similar to small dark lymphocyte

4. Migrating cell

5. Pluripotential cell (gives rise to different cells)

6. Self-supporting cell

7. Rarely dividing cell (Go)

8. Sensitive cell

Mononuclear macrophagic system

Differences between embryonic

and postembryonic hematopoiesis

Embryonic Postembryonic

Histogenesis of blood

Blood physiologic regeneration

Extracorporal (extraembryonic)

Intracorporal

Intravascular Extravascular

Occurs in different organs

RBM

Megaloblastic erythropoiesis mesoblastic

Normoblastic

CLASSES OF HEMATOPOIETIC CELLS

I class – polipotent (pluripotent) stem cell

II class – hemistem cells for lymphocytopoiesis and myelopoiesis

III class – unipotent cell (committed) sensitive to exact hemopoietin (erythropoietin, leykopoietin, thrombopoietin)

IV class – blasts (young actively dividing cells)

V class – maturing cellsVI class – an “adult” mature cells

in peripheral blood

Erythropoiesis 1. Decrease in cell size (from 20 till 8 мm)2. Ejection (extrusion) of the nucleus3. Accumulation of hemoglobin in the cytoplasm4. Basophily decrease and acidophily increase

ERYTHROPOIESIS

GRANULOCYTOPOIESIS

GRANULOCYTOPOIESIS

1. Decrease in the cell size

2. Chromatin condensation

3. Changes in nuclear shape (flattening – indentation – lobulation).

4. Accumulation of cytoplasmic granules.

LYMPHOCYTOPOIESIS

LYMPHOCYTOPOIESIS

1. Begins in red bone marrow and then continues in lymphoid tissue

2. Lifespan varies in different types of lymphocytes

3. Antigenindependent development – in the central hematopoietic organs (red bone marrow and thymus) and antigendependent – in peripheral ones (spleen, lymph nodes and nodules)

MONOCYTOPOIESIS

1. Decrease in cell diameter

2. Decrease in nuclear diameter

3. Cytoplasm basophily decreases

4. Nucleus changes its shape from round to kidney-like

MONOCYTOPOIESIS

Trombocytopoiesis

Megakaryocyte