Notes on Female Reproductive Physiology

Overview of Female Reproductive Physiology

• Oogenesis: The process of ovum formation.

• Cycles:

  • Ovarian Cycle: Involves the development and release of ova.

  • Hormonal Cycle: Regulates and drives the ovarian and endometrial cycles.

  • Endometrial Cycle: Prepares the uterine lining for possible implantation.

Anatomy of the Female Reproductive System

• Ovary: Produces gametes (ova) and hormones.

  • Suspensory Ligament of Ovary: Supports the ovary.

  • Ovarian Ligament: Attaches the ovary to the uterus.

• Uterine Tube: Transports the ovum from the ovary to the uterus.

  • Infundibulum: Funnel-shaped end near the ovary.

  • Fimbriae: Finger-like projections that help capture the ovum.

• Uterus: Hosts the developing fetus.

  • Endometrium: Inner lining, rich in blood vessels, undergoes cyclical changes.

  • Myometrium: Thick muscle layer for contractions.

  • Perimetrium: Outer layer covering the uterus.

• Vagina: Birth canal and receptacle for sperm.

Development of Ova

• Follicular Development:

  • Ova develop in follicles, progressing through several stages:

  • Primary Follicle

  • Secondary Follicle

  • Mature (Graafian) Follicle

  • Corpus Luteum: Formed after ovulation; secretes hormones to maintain the uterine lining.

  • If no pregnancy occurs, it degenerates into corpus albicans.

The Menstrual Cycle

• Interrelated Cycles:

  • Hormonal Cycle: Involves GnRH, FSH, LH, estrogen, and progesterone.

  • Ovarian Cycle: Ovaries follow a cyclical pattern leading to ovulation.

  • Endometrial Cycle: Uterus prepares for implantation.

• Phases of the Endometrial Cycle:

  1. Menstrual Phase: Shedding of the endometrium.

  2. Proliferative Phase: Rebuilding the endometrial lining.

  3. Secretory Phase: Thickening of the lining, readying for embryo implantation.

Hormonal Regulation

• Hypothalamic-Pituitary-Gonadal Axis: The interplay of hormones regulates the menstrual cycle.

  • GnRH: Released from the hypothalamus stimulating FSH and LH.

  • FSH and LH: Hormones from the anterior pituitary driving follicle development and ovulation.

• Hormonal Fluctuations: Hormone levels fluctuate predictably throughout the cycle.

  • Estrogen and Progesterone: Produce predictable cyclical changes affecting the ovaries and endometrium.

Effects and Functions of Female Hormones

• Hormones influence:

  • Growth of sex organs and reproductive tissues.

  • Maturation of breast tissue.

  • Female pattern fat deposition, focusing on hips and thighs.

Birth Control Methods

• Hormonal Methods:

  • The Pill: Low doses of estrogen and progesterone prevent ovulation.

  • RU 486: Allows for abortion by blocking progesterone.

  • Morning After Pill (Plan B): High doses of hormones to prevent ovulation or implantation.

  • Nexplanon/Depo Provera: Long-acting hormonal contraceptives.

• Barrier Methods:

  • Condoms, diaphragm, cervical cap, sponge.

• Male Birth Control:

  • Vasectomy: Surgical procedure to block sperm transport.

  • Male Pill: Under research to inhibit hormone levels that support sperm production.

Development and Pregnancy

• Fertilization:

  • Oocyte is fertilized in the uterine tube.

• Embryo Development:

  • Fertilized egg develops into a blastocyst and implants into the endometrium.

• Placenta: Forms to exchange nutrients and waste between mother and fetus.

Key Processes and Definitions:

• Ovulation: Release of the mature ovum.

• Menstruation: Shedding of the uterine lining if no fertilization occurs.

• Menopause: Cessation of menstrual cycles due to aging and depletion of ovarian follicles.