Overview
This lecture covers the anatomy, histology, functions, and hormonal cycles of the female reproductive system, including external and internal structures, ovarian/uterine cycles, and related glands.
Gross Anatomy of the Female Reproductive System
- The main organs include the ovaries, uterine (fallopian) tubes, uterus, and vagina.
- Female external genitalia consist of the clitoris, labia majora, and labia minora.
- Labia majora contain adipose tissue, hair, and are homologous to the male scrotum.
- Clitoris is erectile tissue equivalent to male corpus cavernosum.
- Urethral glands and greater vestibular glands provide lubrication during arousal.
Internal Pelvic Anatomy and Ligaments
- Two ovaries, each connected to a uterine tube leading to the uterus.
- The uterus is held in place by broad, ovarian, suspensory, uterosacral, round, and cardinal ligaments.
- Suspensory ligaments carry ovarian blood vessels (ovarian artery and vein) to the ovarian hilum.
Ovaries and Oogenesis
- Ovaries contain oocytes inside follicles; primary oocytes are present at birth.
- Oogenesis: the process of egg production; primary oocytes mature into secondary oocytes at puberty.
- Ovulation is the release of a secondary oocyte around day 14 of the ovarian cycle.
- Follicular cells left after ovulation form the corpus luteum, which secretes progesterone.
Ovarian and Uterine Cycles
- Ovarian cycle phases: follicular (days 1-14, FSH-driven follicle growth) and luteal (post-ovulation, corpus luteum activity).
- Uterine (menstrual) cycle phases: menstrual (shedding), proliferative (regrowth via estrogen), secretory (thickening via progesterone).
- Hormones involved: FSH (follicle growth), LH (ovulation and corpus luteum), estrogen (endometrial growth), progesterone (endometrial preparation).
Fertilization and Clinical Notes
- Fertilization usually occurs in the ampulla of the uterine tube within 12-24 hours after ovulation.
- Ectopic pregnancy is implantation outside the uterus and is life-threatening.
- Tubal ligation is the female sterilization procedure (cuts uterine tubes).
- Pap smears screen for cervical cancer by sampling cervical cells.
Uterus, Vagina, and Vulva
- Uterus regions: fundus (top), body (middle), cervix (bottom).
- Endometrium (lining) has a functional layer (sheds) and a basal layer (regenerates).
- Myometrium is a thick muscle responsible for uterine contractions.
- Vagina is a muscular tube; normal flora sustain an acidic environment limiting pathogens.
- Vulva includes the vestibule, labia majora/minora, and clitoris.
Mammary Glands and Sexual Response
- Breasts contain mammary glands, lobes, and lactiferous ducts for milk production.
- Prolactin stimulates milk production; oxytocin triggers milk release and uterine contractions.
- Parasympathetic stimulation during arousal causes clitoral erection, vaginal moisture, and breast changes.
Key Terms & Definitions
- Oogenesis — the process of egg (oocyte) production in the ovaries.
- Ovulation — release of a mature egg (secondary oocyte) from the ovary.
- Corpus luteum — leftover follicle cells producing progesterone after ovulation.
- Menstrual (uterine) cycle — cyclical changes in the endometrium: menstrual, proliferative, secretory phases.
- Ectopic pregnancy — implantation of a fertilized egg outside the uterus.
- Pap smear — test for cervical cancer using cervical cell samples.
- Fimbriae — finger-like projections at the uterine tube end capturing the ovulated egg.
Action Items / Next Steps
- Review diagrams of pelvic anatomy, ovarian, and uterine cycles.
- Study the roles of key reproductive hormones.
- Complete assigned readings on reproductive physiology.