Download blood cells

Histology
Dr. Abdulla aaid
Blood is a specialized connective tissue composed of formed elements and a
fluid component (the extracellular matrix) known as plasma.
The formed elements are composed of cells and cell fragments, known as
platelets(erythrocytes RBCs, Leukocytes WBCs and Platelets) .
Plasma : composition of plasma :
a- plasma protein (Albumin alpha, beta, gamma globuin and
fibrinogen ).
b- Inorganic salts .
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Histology
Dr. Abdulla aaid
c- Organic compounds (Amino acid ,Vitamins , hormones ,
lipoprotins , etc.)
Erythrocytes (RBCs) :
1-Biconcave disks .
2- without nucli.
3-Surrounded by a plasma elements .
4- Survive in the circulation for about 120
days .
Erythrocytes (RBCs)
Leukocytes (WBCs) :
Classification on the basis of the type of granule in the cytoplasm and the
shape of the nucleus .
1- Granulocytes
2- Agranulocytes .
1- Granulocytes (polymorphonuclear leukocytes )
a- Neutrophils b- Eosinophils
c- Basophiles .
2- Agranulocytes (Mononuclear leukocytes ):
a- Lymphocytes
b- monocytes
Leukocytes :
1- Are spherical , no motile cells when in suspension in the circulating
blood .
2- Capable of becoming flattened and motile on encountering a solid
substrate.
3- Are involved in the cellular and humoral defense against foreign material
.
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Histology
Dr. Abdulla aaid
** Diapedesis : Leukocytes leave the capillaries by passing between
endothelial cells and penetrating the connective tissue .
Leukocytes :
1- Neutrophils ( polymorphonuclear leukocytes ):
It is nucleus consists 2-5 lobes .
2- the lobes are linked to each other by fine threads of chromatin .
3- immature Neutrophils a non segmented nucleus in the shape of a
horseshoe .
Eosinophils :
1- Are much less numerous than
neutrophils .
2- Contains a bilobed nucleus .
3- Presence of many large granules .
4- A major function is phagocytosis
and disposal of antigen – antibody complexes
.
Neutrophils &
Eosinophils :
 * Eosinophilia :An increase in the number of eosinophils in blood
which is associated with allergic reactions and helminthic (parasitic )
infections .
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Histology
Dr. Abdulla aaid
Basophiles :
1- the nucleus is divided into irregular lobes .
2- Have a less heterochromatic nucleus .
3- Basophilic granules contain heparin and
histamine .
4- Capable of amoeboid movement and
phagocytosis .
Basophiles
Lymphocytes :
1- lymphocytes differentiate into T or B lymphoc
2- The cytoplasm is scanty , it appears as a
thin rim around nucleus
.
Lymphocytes
Monocytes :
1- bone marrow –derived a granulocytes .
2- the nucleus is oval horse shoe –shaped or
kidney –shaped and eccentrically placed .
Monocytes :
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Histology
Dr. Abdulla aaid
3- Monocytes cross the capillary walls and enter the connective tissue ,
then differentiate into macrophages .
Platelets (Thrombocytes).
1- Are non nucleated , disk like cell fragmentswhich originated from
megakaryocyte .
2- They promote blood clotting and help repair gaps in the walls of blood
vessels , preventing loss of blood .
Platelets (Thrombocytes).
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