Certain cells of the body in addition to carrying out some metabolic processes necessary for their own existence, also manufacture specific substance not for their own use, but to be extruded, from the cells and used elsewhere in the body – secretion(e.g. gastric juice) or discarded – excretion (e.g. urine). Such cells are known as gland cells or […]
‘Reticulo-endothelial system‘ name is given to the system more on physiological and pathological consideration than on anatomical structure. The cells of this system do not form true endothelium. All highly phagocytic cells of the body, except leucocytes belong to this system. The only certain method of identification of these cells is by injection of nontoxic
special connective tissue of animals are -Reticular Tissue, Adipose Tissue, Brown fat tissue, Pigmented Connective Tissue Reticular tissue It is composed of cells and reticular fibre network. The cells have stellate shape with processes which extend in all directions and joins those of wrapped by reticular fibres. The reticular tissue forms the frame work of
Dense connective tissue fibers are closely packed to form sheets, cords or bands (e.g dermis, capsules of certain organs, aponeurosis, ligaments and tendon) based on the nature of arrangement of the fibres. They are classified into two groups Irregularly arranged Regularly arranged Dense irregularly arranged connective tissue occurs in the form of sheets. Main component
Loose or areolar connective tissue is very widely distributed in the body. It forms the superficial and of the deep fascia; forms part of the frame work (stroma) of most of the organs; or surrounds blood vessels and nerves and fills in any otherwise unoccupied spaces. Areolar tissues contain cells, fibres and ground substance. CELLS
There are two varieties of Embryonal connective tissue present- Mesenchyme and Mucous. Mesenchyme consists of a network of branching cells, in the meshes of which is a homogenous intercellular fluid. The processes of a cell appear to anastomose with those of other cells. As development progresses, wavy primitive fibres appear between branching cells and the
Classification of Connective tissue described in this figure-
The various types of adult connective tissues in contrast to epithelium have relatively a few cells and a large amount of intercellular substance. But the proportion of these two elements shows variations. In some type, especially loose connective tissue, cells are quite numerous. In other types, they are few in number and tissue is composed
Stratified epithelium are classified on the basis of the number of cell layers and the shape of the cells in the surface layer. If there is only one layer of cells in the epithelium, it is designated simple. If there are two or more layers of cells, it is termed stratified. Cells in the surface
These are the Special features of epithelium described below- Glandular epithelium It refers to the lining and secretary cells of the glandular organs, which are developed as down growths from the epithelial layer in the underlying connective tissue, followed by structural modification and differentiation. Neuro-epithelium It denotes the specialized epithelial cells in certain locations, which
