Glands may be classified as cytogenous and non-cellular based on the nature of secretion Cytogenous gland produces living cells as their secretion. Eg. Testis, Ovary. Non-cellular glands are further classified into serous, mucous and mixed glands based on the consistency of their secretion
Based on the mode of secretion classification is based on the manner in which the secretory cells of the glands elaborate their secretion. Based on this glands are classified into Holocrine, merocrine and apocrine gland. In holocrine glands, the secretory products are accumulated in the cytoplasm of a cell, which disintegrates fully and constitutes the secretion secreted
Glands are classified into Simple and compound glands on based on the ductular system The ductular system of a gland may consist of simple epithelial tube draining a secretory unit and opening at the epithelial surface or it may be in the form of an extensively branched system, the initial smallest ducts draining the secretory
Based on the shape of the secretory unit- If the secretory units are tubular in shape it is a tubular gland. If secretory units are more rounded, then they are called alveolar or acinar glands. Glands which have characteristics of both these, or which have tubular portions with terminal alveoli, are called tubulo-alveolar glands.
The exocrine gland consists of a secretory portion and a duct. The secretory portion is arranged as a cluster of secretary cells known as a secretory unit, which has a central lumen, which opens into the first portion of the ductular system. The exocrine glands can be classified in several different ways based on the
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
