Composition:suspension of cells in a complex liquid

(plasma)

Plasma: * H2O + organic molecules + mineral salls* After coagulation (- Fibrinogen) = serum

Blood Cells:* R.B. C * W. B. C. * platelets.

Origin:Site:* In the embryo (Liver, Spleen, Bone marrow)* After birth (only in the Bone marrow)* Lymmphoid tissues (B.M., L.N., Spleen, Payer's patches)

HEMOPOIESIS

1-Erythropoiesis:The erythroblastic line represents 10 -30% of the

bone marrow cells.2-Steps of maturation: It take 7 days under normal condition.1- Erythroblast (pronormoblast)2-Basophilic Normoblast3- Polychromatic normoblast.4-Orthochromatic normoblast.5-Reticulocyte6- R. B. C

4-In Cases or Urgent Blood Loss:E.g.: - after haemolytic attack

- after Hge1- Hypersecretion of erythropoietin2- Augmentation of no. of erythroblasts in B. M. resulting in:3- Acceleration of Hb. synthesis normal corpuscular conc. or Hb. occurs early decrease the number of cell divisions between stage of erythroblast and reticulocytes -- reduction of duration of erythropoiesis to 3-4 days.N.B as a result of Hyper secretion of the erythropoietin and acceleration of Hb. synthesis. Hypererythropoiesis occurs.

HYPERERYTHROPOIESIS

a- Increase in number or reticulocytes in the peripheral blood b- presence of immature R.B.CS (polvchromatophilia )c- Macrocytosis. (duo to reduction of number of mitoses between proerthroblasts and Reticulocytes)d- Some orthochromatic normoblasts may be found in the peripheral Blood

5-Exogenous Factors necessary for Erythropoiesis:

1-Iron2-Folic acid and Vitamin B12

EXAMINATION OF THE BLOOD:COMPLETE BLOOD PICTURE (C.B.C.)

A-QUANTITATIVE EXAMINATION:1-Quantitative Exam. of the RBCS with its constituents:a- R.B.Cs no./mm3:Male 4.5 – 6.2 x 106

Female & Child: 4 – 5.4 x 106

Infant 3.6 – 5 x 106

at Birth 5 – 6 x 106

b- Hematocrite: (relative volume of R.B.CS in the blood) - By centrifugation of a small column of blood in a standard tube:

Male 40 - 54 %Female 35 - 47 %

c- Hb. Content of 100 cc blood:Male 13 - 18 gm/100ccFemale & Child: 12 - 16 gm/100ccInfant 12 - 16 gm/100ccat Birth 14 - 20 gm/100cc

f- Reticulocytic count: - Normal life span of RBCs = 120 days - Reticulocytes are the newly fabricated RBCs within the 1st 24 hours (still containing cytoplasmic organelles) i.e. --- by special stain --- counting the no. of RBCs containing such organells among 1000 RBCs in %. - Absolute no. of reticutocytes: = RBCs count X reticulocytic %. * normal 25.000 ----- 100.000/mm3 (l-2 %) For Hb content within the normal range.* with anaemia increase in no. of the reticulocytes , if there is a normal ability of the B.M. to synthesis RBCs i.e., If Hb <= 8 gm in regenerative anaemia (e.g., haemolytic or post Hgic) -- reticulocytic count must be > 100.000 . If < 100.000 this means aregnerative, i.e., ( hypoplastic or aplastic ) anaemia.

2 - Quantitative Exam. of WBCS:Normal4.000 --- 10.000/mm3 in adultsInfants 1st year 5.000 - 20.000 /mm3

2nd year 6.000 – 17.000 / mm3 10 years 5.000 --- 13.000/mm3

N.B. In adult. * > 11.000 indicates leucocytosis * < 4.000 indicates leucopenia.

3- QUANTITATIVE ESTIMATION OF PLATELETS:

Normal l50.000 - 450. 000/mm3

< 150,000 indicates thrombocytopenia. >450.000 indicates thrombocytosis

B- MORPHOLOGIC EXAMINATION:RBCs Morphological exam. of RBCs.WBCS Differential white cell count.

I- Morphologic Examination of RBCs: Normally : RBCs are of * same form * same colour * same diameter.

Any abnormality Pathological condition: * in size : anisocytosis* in form: poikilocytosis

II- Differential white cell Count:-The absolute no. more important than

the %

Polymorphonuclear Neutrophils:* 40 – 70% of WBCS (1700 - 7000)

* Function: The main Function is phagocytosis of

foreign bodies esp. Bacteria

Granulopoiesis: It takes 10 days under normal conditions50 -70 % of B. M. cells

- Myeloblasts 2.3 %- Promyelocytes 4-8%- Myelocytes 10-15%- Metamyelocytes 15-20%- Polynuclear cells 20-30%

* Life span: in the circulation is very short within 12 hours . 50% of formed neutrophils leave the blood to the tissues and don't turn back again.

In cases of excess demand:

Rapid passage of neutrophils to the blood from the marrow resulting in the release of band forms, even metamyelocytes and myelocytes.

Polymorphonuclear leucocytosis: Due to increase polymorphonuclear neut. i.e.> 7000/ mm3

1- Reactional:a- physiologic:

- Neonates - Severe exercise - Menestruation - Pregnancy

b- Pathologic: - Bacterial infections - Inflammatory diseases : (Arthritis - Allergic ) - Tissue necrosis e.g., rnyocardial Infraction,

pancreatitis - Heavy smokers. - Acute hemorrhage or hemolysis - Intoxication (radiation, benzene) - Start of chronic myeloid leukemia - Without cause

2- Myeloproliferative disorders: as Chronic Myeloid 1eukemia Neutropenia: means that Neutrophils < 1700 / mm3, It is due to either:1- Insufficient production (central): A- As a part of Pancytopenia: e.g., aleukemic leukemia or aplastic amenia B- Isolated:

1- Hereditary form.2- Allergy to certain drugs3- Direct central inhibition e.g., henothiazine4- Constitutional agranulocytosis.

2- Hyperdestruction (peripheral):- Auto immunisation- Lupus Erythromatosis . Usually with

thrombocytopenia- Felty's syndrome

# But espe. in moderate cases (i.e. 800- 1700) we must exclude :

-Some parasitic infections (kala Azar)- Some bacterial infections (typhoid, Brucellosis)- Some viral infections (Viral hepatitis)- May be normal esp. in black races.

Eosinophiles:* Functions: (not exactly known)

- phagocytosis : Ag- Ab complex- Transport the plasminogen - Play a role in destruction of certain

larvae - Has a role in allergy

Eosinophilia:means eosinophils > 300/mm3 but more significant if > 500/mm3

causes:1- Allergic conditions:

- Asthma, - Allergy to certain drugs as penicillin's.

2- parasitic infections: Filariasis, Ascaris, Oxyuris, Taeniasis.

3- Polyarteritis nodosa4- Dermatosis 5- Malignancy: - H.D

- certain cancers (Liver, Ovary)

Basophils:* Function:

- Unknown.- Rich in histamine and heparin- Play a role in delayed hypersensitivity reaction

If >1 % = pathologic conditions:1- Myeloproliferative syndromes esp. C.M.L2-Severe hyperlipidaemia3- Hypothyroidism

Monocytes:- The largest circulatory blood cells, have:

* characteristic Nuclear shape,* Longer life span than other WBCs (2-3 days)

Function:1- phagocytosis : Play a role in defence mechanism

In tissues --- Macrophages 2- Play a role in immunologic reactions

Monocytosis:means monocytes > 1000 /mm3: 1- reactional:

- infections: (bacteria, virus parasites) - At the recovery of agranulocytosis

2- Acute monocytic leukemia, chronic myelomonocytic leukemia3- Isolated chronic Monocytosis :

rare as in refractory anaemias at the start of acute monocytic Leukemia, and chronic myelomonocytic eukemia.

Lymphocytosis:Means increased number of lymphocytes above the upper limit of normal (> 4000 – 4500/cumm in adults , > 6000- 7000 , cu mm in neonates and infants.

Causes: 1. Viral infections : hepatitis, measles, infective

mononucleosis2. Bacterial infections : brucellosis , T.B., whooping

cough.3. Malignant lymphocytosis : Chronic lymphatic

leukemia and Waldestron’s macroglobulinemia.