histology of blood

HISTOLOGY OF BLOOD(specialized connective tissue)

Plasma 55% (straw colored)

92% water
8 % Salt, nutrients, proteins , waste, gases, hormones
BUFFY COAT (Gray- White) 1%
WBC
Platelets
RBCs 45%

Blood is a viscous fluid formed of cellular elements suspended in plasma.

Composition of whole blood(5 L in adult)

Plasma Proteins:
■ Albumin
■ α Globulins and β Globulins
■ γ Globulins
■ Fibrinogen
■ Complement proteins

HEMATOCRIT Ratio of RBCs to Plasma, 45%

Anticoagulant& Clot formation

Clotting prevented by (heparin or citrate)
When Blood extravasated, Plasma proteins react with one another to produce a (clot) & serum
Serum is a pale yellow liquid

Blood smear

Erythrocytes
largest number of cells in the blood
3.9 to 5.5 million (μL, or mm3) in women
4.1-6.0 million/μL in men.
Biconcave discs
No nucleus
Contain Hemoglobin

Rouleaux RBCs adhere to one another loosely in stacks.

Plasma Membrane of RBC

40% Lipid
10 % Carbohydrate
50 % Proteins------- (1) integral proteins
(2) peripheral proteins

Integral Proteins Band3 proteinGlycophorinsperipheral proteinsspectrinAnkyrin

Integral & peripheral proteins

BLOOD TYPES

Abnormal Hemoglobin HbS

Leukocytes (4500 -11000/μl)
GRANULOCYTES
AGRANULOCYTES

Granulocytes

Neutrophils
Eosinophils
Basophils

Neutrophils (PMNs)

Most numerous WBC in blood
Multilobed nucleus
Granules:
Azurophilic granules
Specific granules
Function
1st wave of cells in acute inflammation; can phagocytose bacteria

Eosinophils

Bilobed nucleus
Bright pink Granules
Function:
Important in allergic rxns, parasitic infections, and phagocytosis of Ab-Ag complexes

Basophils

Rare!
Lobulated (S) shaped nucleus
Dark Blue Granules obscuring nucleus
Hydrolytic enzymes, heparin sulfate, histamine, SRS
Function
Role in hypersensitivity and anaphylaxis

Agranulocytes

Lymphocytes ( T & B cells)
Monocytes (Macrophage)

Lymphocytes

Smallest leukocytes, About size of RBCs
Most numerous type of agranulocyte, 1/3 of all WBC
Spherical nuclei with rim of scant cytoplasm
TYPES
T cells(CD4, CD8)
B cells
Natural Killer (NK) cells.

Monocytes

Largest WBCs in blood smear
Indented (C ) shaped nucleus
Migrate through blood to the tissues; once in tissues they differentiate into phagocytes (macrophages)

Platelets

Non-nucleated
Membrane- bound cell fragments
Derived from Megakaryocytes
2-4 μm in diameter
150,000 to 400,000/μL (mm3)
Function in blood clotting







Hyalomere ----------- Lightly stained peripheral zoneGranulomere ------ Darker-staining central zone containing granulesGlycocalyx --------- Involved in adhesion & activation during coagulation

Blood coagulation

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