Female Reproductive System Basics
📌 Menstruation is defined as the shedding of blood and tissue from the uterus through the vagina, typically occurring once every 28 days.
👶 Menarche marks the onset of menstruation, usually happening between the ages of 11 to 15.
🛑 Menopause is when ovaries cease producing egg cells, normally occurring between ages 45 and 55, making fertilization impossible.

The Menstrual Cycle Phases
🗓️ The menstrual cycle spans approximately 28 days and includes four main phases: Menstruation (Flow Phase), Follicular Phase, Ovulation, and Luteal Phase.
🩸 The Flow Phase (Days 1–5) involves the shedding of the endometrium; estrogen and progesterone levels are low during this time.
🥚 The Follicular Phase (Days 6–13) is characterized by the growth and maturation of follicles, leading to estrogen secretion and stimulation of LH.
💥 Ovulation is a single-day event (around Day 14) where the egg cell bursts from the follicle, causing very high LH levels.
🔄 The Luteal Phase begins as the ruptured follicle transforms into the corpus luteum, which secretes estrogen and progesterone to maintain the thickened endometrium.

Hormonal Regulation and Feedback Mechanisms
🧠 The reproductive system is regulated by hormones released from the hypothalamus (producing GnRH) and the pituitary gland (releasing FSH and LH).
📈 Positive feedback is exemplified before ovulation, where estrogen stimulates the increased production of GnRH and LH.
📉 Negative feedback occurs after ovulation; the progesterone released by the corpus luteum inhibits the production of both GnRH and LH.

Key Points & Insights
➡️ Understanding the menstrual cycle requires recognizing the interdependence of the uterine lining changes and the fluctuations of key hormones: Estrogen, Progesterone, FSH, and LH.
➡️ Ovulation is the critical one-day window for potential pregnancy, characterized by a surge in LH levels causing the egg release.
➡️ Maintaining homeostasis (balance) in the system relies on the switch between positive feedback (stimulation) before ovulation and negative feedback (inhibition) during the luteal phase.

📸 Video summarized with SummaryTube.com on Nov 27, 2025, 19:38 UTC