Diseases of women : a textbook for students and practitioners / by J.C. Webster.

  • Webster, John Clarence, 1863-1950.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Diseases of women : a textbook for students and practitioners / by J.C. Webster. Source: Wellcome Collection.

    32/736 (page 4)
    consists of a covering of low epithelial cells, derived from the original germ epithelium, which surrounds the primordial ovum. The latter is a rounded cell with a single nucleus ; very rarely with two nuclei. Nagel measured the ovaries fresh in salt solution, and found their diameters to vary from 48 by 54 /x to 64 by 69 /x. The nucleus (germinal vesicle), situated in the centre of the ovum, measured from 29 to 32 /a; Trinchese and others have described around it a membrane with a double outline. There is a nucleolus (germinal spot) centrally or peripherally placed, as well as one or more paranucleoli. The grotving These are found in the lower portion of the cortical layer. The first sign of growth in the primary follicle is that the epithelial cells surroundmg the ovum increase in size and number, forming a mass of several layers—granulosum. In this vacuolation occurs, in which gradually accumulates the liquor foUicuh, formed partly by transudation from the surrounding tissues, partly by breaking down of cells of the stratum granulosum. Those cells which do not break down remam as a kmd of stalk {discus proligcrus, cumulus oopfwrus), in which the ovum is embedded. While these changes are taking place in the stratum granulosum the surrounding connective tissue elements are being arranged concentrically, to form an outer covering of the follicle-the theca folliculi. This consists of two portions, the tunica externa or fibrosa and the tunica interna or nroDria The latter is more cellular than the former, and is rich in capillaries. Between the theca and the stratum granulosum is a thin structureless membrane, produced by the epithelial cells, according to Waldeyer. About the time of the appearance of this so-called base- ment membrane the thin structureless zona pdlucida is fo med around the ovum from the epithelial cells Accord- ng to Nagel a very thin space, the periv.tellme space, xist between it and the ovum. Next appears in the