Question

what is relation between division of labour and various types of tissues?

Answer 1

tissues, includes Cytology which was considered in the preceding chapter. The cells formed by successive mitoses from the fertilized egg differentiate into various tissues that constitute the body. A tissue is an association of similar cells which have undergone specialization for some particular purpose, and intercellular material, the amount of which varies greatly in different tissues. Thus, bone tissue includes bone cells, that are very much alike, and a considerable amount of hard intercellular material, while epithelial tissue is an association of epithelial cells, that resemble each other, but contain a minimum amount of intercellular substance.

The similar cells constituting a tissue may be connected with each other either by delicate strands of cytoplasm that penetrate the enclosing cell walls, or by an intercellular ground substance of some sort either secreted by the cells themselves in the form of exaggerated cell walls, or formed out of intruded interstitial material arising extraneously, like mortar between bricks.

Combinations of tissues make organs in much the same way that different textiles are combined into garments, and in turn organs make systems, just as different garments together make costumes. For example, the stomach is an organ that is assembled out of muscle tissue, blood tissue, gland tissue, nerve tissue, and the like, which together with other organs like the teeth, intestine, and pancreas, forms the digestive system.