1256 



SPLANCHNOLOGY 





Fibro-vascular coat 

 Membrana granules 



The stroma is a peculiar soft tissue, abundantly supplied with bloodvessels, consisting for the 

 most part of spindle-shaped cells with a small amount of ordinary connective tissue. These 

 cells have been regarded by some anatomists as unstriped muscle cells, which, indeed, they 

 most resemble; by others as connective-tissue cells. On the surface of the organ this tissue is 

 much condensed, and forms a layer (tunica albuginea) composed of short connective-tissue 

 fibers, with fusiform cells between them. The stroma of the ovary may contain interstitial cells 

 resembling those of the testis. 



Vesicular Ovarian Follicles (Graafian follicles). Upon making a section of an ovary, numerous 

 round transparent vesicles of various sizes are to be seen; they are the follicles, or ovisacs con- 

 taining the ova. Immediately beneath the superficial covering is a layer of stroma, in which are 

 a large number of minute vesicles, of uniform size, about 0.25 mm. in diameter. These are the 

 follicles in their earliest condition, and the layer where they are found has been termed the 

 cortical layer. They are especially numerous in the ovary of the young child. After puberty, 

 and during the whole of the child-bearing period, large and mature, or almost mature follicles 

 are also found in the cortical layer in small numbers, and also "corpora lutea," the remains of 

 follicles which have burst and are undergoing atrophy .and absorption. Beneath this superficial 

 stratum, other large and more or less mature follicles are found imbedded in the ovarian stroma. 

 These increase in size as they recede from the surface toward a highly vascular stroma in the 

 center of the organ, termed the medullary substance (zona vasculosa of Waldeyer). This stroma 

 forms the tissue of the hilum by which the ovary is attached, and through which the bloodvessels 

 enter: it does not contain any follicles. 



The larger follicles (Fig. 1164) consist of an external fibro vascular coat, connected with the 

 surrounding stroma of the ovary by a net-work of bloodvessels; and an internal coat, which con- 

 sists of several layers of nucleated 



^g^^_ cells, called the membrana granulosa. 



At one part of the mature follicle the 

 cells of the membrana granulosa are 

 collected into a mass which projects 

 into the cavity of the follicle. This 

 is termed the discus proligerus, and 

 in it the ovum is imbedded. 1 The 

 follicle contains a transparent albumin- 

 ous fluid. 



The development and maturation 

 of the follicles and ova continue un- 

 interruptedly from puberty to the end 

 of the fruitful period of woman's life, 

 while their formation commences be- 

 fore birth. Before puberty the ovaries 



Discus proligerus - ' ' jft&*> &.'*!]* V: VJ/'Y are sma11 and the folli des contained 



in them are disposed in a compara- 

 tively thick layer in the cortical sub- 

 stance; here they present the appear- 

 ance of a large number of minute 

 closed vesicles, constituting the early 

 'cat. x 50. condition of the follicles; many, 

 however, never attain full develop- 

 ment, but shrink and disappear. At puberty the ovaries enlarge and become more vascular, 

 the follicles are developed in greater abundance, and their ova are capable of fecundation. 



Discharge of the Ovum. The follicles, after attaining a certain stage of development, gradu- 

 ally approach the surface of the ovary and burst; the ovum and fluid contents of the follicle 

 are liberated on the exterior of the ovary, and carried into the uterine tube by currents set up 

 by the movements of the cilia covering the mucous membrane of the fimbrise. 



Corpus Luteum. After the discharge of the ovum the lining of the f ollicle is thrown into 

 folds, and vascular processes grow inward from the surrounding tissue. In this way the space 

 is filled up and the corpus luteum formed. It consists at first of a radial arrangement of yellow 

 cells with bloodvessels and lymphatic spaces, and later it merges with the surrounding stroma. 

 Vessels and Nerves. The arteries of the ovaries and uterine tubes are the ovarian from 

 the aorta. Each anastomoses freely in the mesosalpinx, with the uterine artery, giving some 

 branches to the uterine tube, and others which traverse the mesovarium and enter the hilum of 

 the ovary. The veins emerge from the hilum in the form of a plexus, the pampinif orm plexus ; 

 the ovarian vein is formed from this plexus, and leaves the pelvis in company with the artery. 

 The nerves are derived from the hypogastric or pelvic plexus, and from the ovarian plexus, the 

 uterine tube receiving a branch from one of the uterine nerves. 



Zona striata 

 Germinal vesicle 



FIG. 1164. Section of vesicula 



1 For a description of the ovum, see page 38. 



