Histology, branch of biology concerned with the structure of plant and animal tissues in relation to their specialized functions. This term came into usage in the 1700s by the scientist Marie François Xavier Bichat who is considered to be the father of modern histology and descriptive anatomy.

Histologists mainly examine the tissue that have been removed from the living body, cut into very thin transparent slices (using a special cutting instrument, the microtome and may then be stained with various dyes, and specifically with the H & E stain, to increase the contrast so that the cells can be more easily resolved using an optical microscope. Ultra structure (or ultra-structure) is the architecture of cells and biomaterials that is visible at higher magnifications than found on a optical light microscope.

In 1931, German engineers, Max Knoll and Ernst Ruska invented the first electron microscope. This traditionally meant the resolution and magnification range of a conventional transmission electron microscope (TEM) when viewing biological specimens such as cells, tissue, or organs.

The Science of Endocrinology deals with the study of Endocrine glands. The Author of this Book has tried to assemble the histological and ultrastructural details of the major endocrine glands with the contribution of Scientists related with these topics.

Hope this will be a immense help to the Researchers in recognizing the structural details with the particular functions of the tissues. .