The document summarizes the female reproductive system, specifically the ovaries and oogenesis (egg formation). It describes the histology and structure of the ovaries, including the germinal epithelium, tunica albuginea, cortex, medulla, and ovarian follicles. It then explains the process of oogenesis, from primordial germ cells to primary oocytes surrounded by granulosa cells in primordial follicles. Upon stimulation by hormones, follicles develop through primary, secondary, and tertiary stages, with the release of a secondary oocyte at ovulation.

1. FEMALE REPRODUCTIVE SYSTEM 2
1. HISTOLOGY OF OVARY
2.OOGENESIS AND FOLLICULAR
DEVELOPMENT
Mrs. Sarita Sharma
Assistant Professor
Department Of Pharmacology
Mumbai

2. OVARY
• FEMALE GONADS
 They are paired glands THAT resmeble unshelled almonds in size and shape
 Located one on either sides of uterus.
 They are homologus to testes( same embryonic origin)
• OVARIES PRODUCE
1. Gametes, secondary oocytes that develope into mature ova(eggs) after
fertilization.
2. Hormones, including PROGESTRONE & ESTROGEN (FEMALE SEX HORMONES),
INHIBIN & RELAXIN

3. OVARIES (CONTI.)
A series of ligaments holds them in
position
• 1.Broad ligament of uterus, a fold
of parietal peritonium, attaches to
ovaries by double layered fold of
peritonium called mesovarium.
• 2. Ovarian ligament-ovary to
uterus
• 3. Suspensory ligament-ovary to
pelvic wall
• Each ovary contains a
hilum(hilus), a point of entrance &

4. HISTOLOGY OF OVARY
1: Germinal epithelium-layer of simple epithelium- covers surface of ovary
2: Tunica albuginea-whitish capsule of dense irregular connective tissue
located immediate after GE.
3: Ovarian cortex- deep to tunica albuginea. Consits of ovarian follicles,
surrounded by dense irregular connective tissues that contains collagen
fibers & fibroblast called stromal cells.
4: Ovarian medulla- deep to ovarian cortex. Consits of more loosely
arranged connective tissue & contains blood vessels, lymphatic vessels&

5. 5: ovarian Follicles- Present In Cortex & Consits Of Oocytes In Various
Development Stages+ cells Surrounding Them.
Surrounding Cells-forming A Single Layer-follicular Cells- Later In Development Forms
Several Layers-granulosa Cells. Surrounding Cells Nourish Developing Oocyte &
Begin To Secrete Estrogens As Follicle Grows Larger.
6: Mature (Graafian) Follicle- Large Fluid Filled Follicle I.E. Ready To Rupture &
Expel Its Secondary Oocyte, A Process Known As Ovulation.
7: Corpus Luteum- Yellow Body-remaining Part After Ovulation. Produce
Progestrone, Estrogen, Relaxin & Inhibin. Until It Degenarate Into Fibrous Scar Tissue
Called Corpus Albicans (white Body)

7. OOGENESISAND FOLLICULAR DEVELOPMENT
• Formation of gametes in ovary is called as oogenesis.
• Oogenesis begins before females are born
• Essentially same steps of meiosis as spermatogenesis
• During early fetal development, primordial (primitive) germ cells migrate
from yolk sac to ovaries
• Germ cells then differentiate into oogonia – diploid (2n) stem cells
• Before birth, most germ cells degenerate – atresia
• A few develop into primary oocytes that enter meiosis I during fetal
development
• Each covered by single layer of flat follicular cells – primordial follicle
• About 200,000 to 2,000,000 at birth, 40,00 remain at puberty, and around 400

8. FOLLICULAR DEVELOPMENT
• Each month from puberty to menopause, FSH and LH stimulate the development of
several primordial follicles
• Usually, only one reaches ovulation
• Primordial follicles develop into primary follicles
• Primary oocyte surrounded by granulosa cells
• Forms zona pellucida between granulosa cells and primary oocyte
• Stromal cells begin to form theca folliculi
• Primary follicles develop into secondary follicles
• Theca differentiates into theca interna secreting estrogens and theca externa
• Granulosa cells secrete follicular fluid in antrum
• Innermost layer of granulosa cells attaches to zona pellucida forming corona
radiata

9. Copyright 2009, John Wiley & Sons, Inc.
OVARIAN FOLLICLES

10. FOLLICULAR DEVELOPMENT
• Secondary follicle becomes mature (graffian) follicle
• Just before ovulation, diploid primary oocyte completes meiosis I (46
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• Produces 2 unequal sized haploid (n) cells – first polar body is discarded
and secondary oocyte
• At ovulation, secondary oocyte expelled with first polar body and corona radiata
• If fertilization does not occur, cells degenerate
• If a sperm penetrates secondary oocyte, meiosis II resumes
• Secondary oocyte splits into 2 cells of unequal size – second polar body (also
discarded) and ovum or mature egg
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