PRACTICAL ROADMAPBLOOD

Mrs. A. Jovanović

Introduction

• Connective tissue is one of the four basic tissue typescharacterized by the three main constituents:

1. Cells2. Fibers3. Ground substance

• Blood is a type of connective tissue with a fluid extracellularmatrix, a protein rich liquid, called plasma

• Blood cells constitute approximately 45% of the blood volumeof which red blood cells make up 99%

Connective tissue

1. Cells

Extracellular matrix

2. Ground substance

3. Fibers

Blood cells Erythrocytes – Red blood cells (RBCs) Leukocytes – White blood cells (WBCs) Thrombocytes (platelets)

Stain used: The modified Romanovsky‐type stain• methylene blue (basic dye)• related azures (basic dye)• eosin (acidic dye)

Note: Plasma proteins found within the blood extracellular matrix do notpossess a structural form above the molecular level. Due to this reasonthe extracellular matrix in the blood smear slides appear as a homogenoussubstance and stains evenly with the relevant stains.

Cells

Erythrocytes

Leukocytes

Thrombocytes

Leukocytes

Granulocytes

Neutrophils

Eosinophils

Basophils

Agranulocytes

Lymphocytes

Monocytes

Erythrocytes

Note: Erythrocytes are anucleatecells devoid of organelles. Theirdiameter is 7.8m often used as ahistological ruler when identifyingdifferent blood cells

Erythrocyte

Extracellular matrix

Leukocytes

• GranulocytesPossess specific and non specific cytoplasmic granules staining with azurophilic stain  (lysosomes)

• Agranulocytes Lack specific granulesbut have non specific azurophilic granules

Neutrophil

Note: 10 – 12 m in diameter. Use histologicalruler to compare the diameter of neutrophilwith that one of the erythrocyte

Multilobed nucleus

Eosinophil

Note: 10 – 12 m in diameter. Apply again the histological ruler technique.The size of the cell, shape of the nucleus and presence or absence of thespecific granules are carefully used when identifying blood cells. Also notethe specific, retractile granules within the cytoplasm which will help you todistinguish these cells among the other granulocytes

Bilobed nucleus

Basophil

Note: 10 – 12 m in diameter. Least numerous and thus verydifficult to find! Lobed nucleus obscured by the granules

Lymphocyte

Note: Mature lymphocyte in blood smear is approximately the samesize as erythrocytes. The small lymphocyte pictured above hasintensely stained slightly indented nucleus with a thin rim of a lightlystaining cytoplasm

Monocyte

Note: 18m in diameter. The largest leukocyte with indented,horse shoe shaped nucleus

Thrombocytes (platelets)

Note: Small, membrane‐bounded, anucleate, cell cytoplasmicfragments (arrows)

Neutrophil and basophil

Neutrophil Trombocytes Monocyte

Eosinophil Lymphocytes Erythrocyte