the vascular tissues (blood)

The Vascular tissue
? These comprise the Blood and lymph only .
They are liquid tissues and flow in vessels . they
are nearest to the connective tissues in structure
? I . The Blood .
Is a fluid connective tissue that circulates through
the cardiovascular system,consisting of cells and
an extracellular matrix.The cells include


? (a)-Red blood cells, are also called the
Erythrocytes they constitute the largest
number of cells in the blood and these round
and enucleated (non-nucleated),and they
biconcave discs.

? (b)-White blood cells ,also called the
Leucocytes are colourless, nucleated , there
are two types of leucocytes:


I - Granulocytes
whose cytoplasm contains granules . According to the affinity of these
granules towards stains, three different categories of granulocytes are
recognized:
?Neutrophils: Are the most numerous of the WBCs as well as the most
common of the granulocytes , they larger than erythrocytes ,have granules
stain well with most dyes . The nucleus of a neutrophil divided into a number
of segments (3 – 5) connected with one another.
?Acidophils: (or eosinophils), whose granules stain with the acid dyes, their
nucleus bilobed .
?Basophils: Have the same size of neutrophils,their granules stain with the
basic dyes and the nucleus is S shaped.

Agranulocytes- 2
whose cytoplasm is free of granules.two categories
are recognized:
?Lymphocytes , are small, with a large nucleus and
little cytoplasm.
?Monocytes, are the largest leukocytes. They
possess a horse – shoe- shaped nucleus.
?( c)- Platelets, they are small in their size and
have a biconvex shape, appear in the peripheral
blood smear either singly or in clusters.