The paired organ is ellipsoid in shape:

• on the outside is covered with a surface (germinal) single-layer cubic epithelium;
• stroma is represented by a dense connective tissue tunica albuginea, continuing in loose connective tissue with a high content of fusiform fibroblasts and fibrocytes;
• contains cortical #1, #2 and medullary #1, #2 regions.

Cortical region — the widest surface layer contains numerous follicles (ovocytes of the first order or primary ovocytes at different stages of growth, surrounded with follicular epithelial cells).

• Primordial #1, #2 (resting) follicles — numerically prevail and are located in the subcapsular zone of the cortex; formed by small primary ovocytes with a rounded light nucleus and finely dispersed chromatin surrounded by a single layer flat follicular cells;
• Primary #1, #2 (developing) follicles are represented by primary ovocytes #1, #2, the volume of which increases due to cytoplasm; contain zona pellucida #1, #2, on the outside is covered with a single layer cubic/prismatic follicular cells #1, #2;
• Secondary #1, #2, #3 (developing) follicles contain:
  • primary ovocyte, surrounded by zona pellucida; on the outside is covered with multilayer follicular epithelium #1, #2 (contains numerous mitotically dividing cells #1, #2);
  • connective tissue sheets (theca), including internal and external layers;
  • theca interna is formed by interstitial #1, #2 (endocrine) cells with rounded nuclei and dense capillary network;
  • theca externa is formed by connective tissue, passing into the ovarian stroma (contains myofibroblasts with elongated nuclei and collagen fibers);
• Tertiary #1, #2 (mature) follicle contains:
  • stratified follicular epithelium with expanded intercellular spaces #1, #2 or single cavity, occupying the main volume of the vesicle;
  • eccentrically located primary ovocyte in the composition of cumulus oophorus, covered with ovocyte membranes ( pellucida, granulosa and corona radiata);
  • follicle wall — parietal layer of follicular epithelium ( granulosa) and double-layered theca (blood vessels are well expressed in the outer layer).
• Atretic bodies #1, #2 consist of overgrown interstitial cells #1, #2 of theca interna with interlayers of loose connective tissue #1, #2 around deformed zona pellucida #1, #2 of dead ovocyte.

Medulla — narrow inner layer #1, #2, consists of loose connective tissue with a large number of cellular and fibrous elements, contains nerve fibers and large convoluted arterial and venous vessels.

At one of the poles of the ovary on the slide preparation, you can see fimbriae #1, #2 fallopian tube funnels (covered with a single-layer prismatic ciliated epithelium).