MH 161 Ovary

Ovary

Ovaries produce female gametes (oocytes) and steroid hormones (estrogen and progesterone).

This specimen has few primordial and primary follicles, but contains several secondary (antral) follicles and many corpus albicans.

outer region that is the site of oocyte development. This specimen is mostly cortex.
- Ovarian Follicles - oocytes surrounded by one or more layers of cells.
  - - oocytes arrested in development. There are very few of them in this specimen.
    - Primary Oocyte - large (25 to 30 µm), round to oval cells with a vesicular nucleus.
    - Follicular Cells - single layer of flattened cells that surround each oocyte.
  - Primary Follicles - primary oocytes surrounded by one or more layers of cuboidal-shaped granulosa cells (which develop from follicular cells). There are few of them in this specimen.
    - - primary oocytes surrounded by a single layer of granulosa cells.
    - - primary oocytes surrounded by multiple layers of granulosa cells. (Note the poor fixation and preservation of this follicle.)

Ovary

- - - characterized by the formation an (a fluid-filled space) containing an oocyte.
    - - large (50 to 100 µm), round to oval cells with a vesicular nucleus. (Nucleus is not visible.)
    - - layer of glycoproteins between the oocyte and granulosa cells (eosinophilic).
    - Granulosa Cells - continue to proliferate and form multiple structures:
      - - several layers of cells immediately surrounding the oocyte.
      - - group of cells anchored to the follicle wall that contains the oocyte.
      - - multiple layers of cells that form the follicle wall that surrounds the antrum. (It is avascular.)
    - - stromal cells around the follicle develop into a sheath of highly vascularized connective tissue.
      - - inner cellular layer with many blood vessels.
        
        Secrete androgens that are converted to estrogen by granulosa cells.
      - - outer more fibrous layer.

Ovary

- - - usually only one follicle will continue to grow each cycle to form a very large, mature follicle (25 mm or more in diameter).
    - Because of its large size, the oocyte is usually not visible in most sections of a mature follicle.
    - - becomes thinner as the follicle continues to grow in size. (It is avascular.)
    - - becomes more organized and contains many blood vessels.
    - - raised area of the ovarian surface where a mature follicle will burst through to release the ovum during ovulation.
- - after a corpus luteum ceases to function it degrades into a that is eventually removed. There are many of them in this specimen.
- - highly cellular connective tissue with fewer connective tissue fibers in which ovarian follicles are located.
  - - spindle-shaped cells.
- inner region of fibro-elastic connective tissue with many large, tortuous , lymph vessels and nerve fibers.
- Does not contain ovarian follicles.