Ovulation coincides with:
**Core Concept**
Ovulation is a critical phase in the menstrual cycle, marking the release of a mature ovum from the ovary. It is a complex process influenced by hormonal fluctuations and the hypothalamic-pituitary-gonadal axis. The timing of ovulation is essential for fertilization and subsequent embryonic development.
**Why the Correct Answer is Right**
Ovulation typically occurs approximately 14 days before the onset of the next menstrual period, coinciding with the mid-cycle surge in luteinizing hormone (LH) secretion. This surge in LH triggers the rupture of the dominant follicle, releasing the ovum into the fallopian tube. The LH surge is mediated by the hypothalamic release of gonadotropin-releasing hormone (GnRH), which stimulates the pituitary gland to secrete LH.
**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect as LH surge is not the only factor influencing ovulation; follicle-stimulating hormone (FSH) also plays a crucial role in follicular growth and development.
**Option B:** This option is incorrect as ovulation occurs in the luteal phase, not the follicular phase; the luteal phase begins after ovulation.
**Option C:** This is incorrect as ovulation does not coincide with menstruation; ovulation occurs before the onset of menstruation.
**Clinical Pearl / High-Yield Fact**
To determine the timing of ovulation, clinicians often use the 'count-back' method, subtracting 14 days from the expected date of the next menstrual period.
**Correct Answer: C. Ovulation coincides with the luteal phase.**