Lecture Notes on Female Reproductive System

Overview of Female Gametes

• Myth: Females are born with all the ova they'll ever have.
  • Truth: Born with all the oocytes, not ova. Ova form at fertilization.
• Main Hormones: Estradiol, estrone, estriol, and progesterone (collectively estrogens).

Anatomy of Female Reproductive System

Key Structures

• Uterus: Pear-shaped, can tilt forward (antegrade) or backward (retrograde).
• Endometrium: Innermost lining.
• Cervix: Neck-like, with the cervical os usually filled with mucus.
• Vagina: Collapsible tube with a superior "fornix" around the cervix.
• Oviduct (Fallopian Tube): Connects ovary and uterus, ending in fimbriae.

Ligaments

• Round Ligament: Supports uterus.
• Utero-sacral Ligament: Anchors uterus.

Development and Function

Follicle Development

• Primordial Follicle: Houses primary oocytes.
• Primary & Secondary Follicles: Develops from primordial.
• Vesicular Follicle: Fully mature, includes an antrum.

Ovulation

• Ovulation: Ejection of a mature oocyte, not an ovum.
• Corpus Luteum: Remnant of follicle post-ovulation, secretes hormones.

Fertilization and Pregnancy

• Fertilization usually occurs in the oviduct.
• Implants into the endometrium and involves placenta formation.

Uterine Cycle

• Layers: Parametrium, Myometrium (muscle), and Endometrium.
• Functionalis: Sheds during menstruation.
• Basalis: Regenerates functionalis.

External Genitalia (Vulva)

• Components: Mons pubis, labia majora, labia minora, clitoris.
• Hymen: Varies greatly among individuals.

Clitoris and Erectile Tissue

• Clitoris: Majority internalized, with erectile tissue similar to the male.

Mammary Glands

• Functional primarily in females for milk production.
• Composed of lobes and lobules, leading to lactiferous ducts.

Oogenesis

• Females are born with all oocytes, not ova.
• Oocytes: Start meiosis in fetal development, paused at birth.
• Polar Bodies: By-products of oogenesis.

Comparison to Spermatogenesis

• Oogenesis: Produces one functional ovum per cycle.
• Spermatogenesis: Produces four sperm per cycle.

Important Concepts

• Error Rates: Higher in oogenesis, increases with maternal age.

Additional Notes

• Vagina Functions: Birth canal, menstrual flow exit, copulation.
• Hymen Variability: Affects first intercourse experience.