Histological  examination  of  the  ovaries  taken  from  cows  on  different  days  of  sexual  cycle  was  found  that  in  cross-
section in all gonads clearly visible protein coat, cortex and medulla, functional formations (follicles at different stages of 
development and corpus luteum), and blood vessels. Externally, the ovaries were covered with a flat, and sometimes cubic 
epithelium with nuclei oval or oblong. Under the epithelium was protein shell - a layer of connective tissue elements with 
different orientations of the cells resembling fibroblasts, between which there is a dense network of collagen fibers oriented 
parallel to the surface of the ovary. Ovarian cortex represented connective substrate (stroma), which were follicles at different 
developmental stages (primordial, primary secondary (vesicular) and tertiary) and yellow body. Strom's crust contains a large 
number of cells between which the collagen fibers. Stromal cells and its fibrous structures have different orientations. Under 
the protein shell in the cortex groups or singly housed primordial follicles. It is composed of the small size of the oocyte, 
surrounded by a single layer of follicular cells. Unlike primordial follicles and primary are large and they are deeper than in 
the cortex. 
Primary oocyte follicle acquired larger and the surrounding rows of 3-5 follicular cells, the cells exposed to the inside 
folders. Around the primary oocyte follicle formed shiny shell. Externally of follicular cell layer formed inside the folder 
where the stromal cells and the collagen fibers are acquired circular orientation. In contrast to the primary follicle gradually 
formed in the secondary cavity (vesicle), which is filled with follicular fluid. With the increase in the number of follicular 
fluid oocyte shifted to one of the poles, which gradually began to take shape oviparous mound. 
Follicular development was accompanied by the drawing up of the ovarian stromal cells of the inner and outer folder. To 
the basement membrane of the follicle, joining several layers of cells with elongated nuclei oriented circularly, that is, to 
create a domestic tech. Around it was located outside the folder, and a large number of small blood vessels. Increasing the 
number of follicular fluid in the cavity vesicular follicle, leading to an increase in its volume and conversion to tertiary folli-
cles. This follicle 9-12 watched series of follicular cells. 
As the follicle increases in volume and is closer to the surface of the ovary, thereby thinning contributed protein shell in 
this area. This follicle follicular cell layer and experienced desquamation dystrophy and separately located in the follicular 
fluid. Such destruction of follicular cells in our opinion is due to the atresia of the follicle and the cessation of its further de-
velopment. 
Also follicles at different stages of development in the ovarian cortex on different days of the sexual cycle found atretic 
corpus luteum. All of them are located at different depths of the crust and were surrounded by stromal cells of the ovary, 
which in turn gradually replaced the substance of the corpus luteum and small clusters were located in the central part. 
Unlike the cerebral cortex was represented by connective elements which contain significant amounts of elastic fibers 
and permeated by a large number of blood vessels of different diameter oriented in different directions. Veins characterized 
by flattened form, and the arteries were more rounded and had a well-defined muscle membrane. Small blood vessels formed 
the entire field, taking a considerable amount of the medulla of the ovary. 
Key words: ovaries, histological, sexual cycle, follicles, corpora lutea.