Menstrual Cycle and Hormonal Regulation - Anatomy and Physiology
- Which ovarian hormone drives the secretory phase of the uterine cycle?
- Progesterone, which makes the endometrial glands secrete nutrients and readies the lining for implantation.
- A woman has a regular 32-day cycle with a 14-day luteal phase. On about which cycle day does she ovulate?
- About day 18. The luteal phase is fairly constant, so ovulation occurs about 14 days before the next menses: 32 minus 14.
- What ovarian event does the LH surge trigger?
- Ovulation, the rupture of the mature follicle and release of the secondary oocyte.
- Which anterior pituitary hormone mainly stimulates follicle growth early in the follicular phase?
- Follicle-stimulating hormone (FSH).
- Which ovarian hormone drives the proliferative phase of the uterine cycle?
- Estrogen, which rebuilds the functional layer of the endometrium.
- Which hormone keeps the corpus luteum alive if pregnancy occurs?
- Human chorionic gonadotropin (hCG), secreted by the developing embryo's trophoblast.
- What triggers the midcycle LH surge?
- High, sustained estrogen from the dominant follicle, which switches to positive feedback on the hypothalamus and anterior pituitary.
- What causes the endometrium to shed at menstruation?
- The corpus luteum degenerates, so progesterone and estrogen fall; spiral arteries constrict and the functional layer dies and sheds.
- Why does basal body temperature rise slightly after ovulation?
- Progesterone from the corpus luteum has a thermogenic effect, raising basal temperature for the luteal phase.
- What are the three phases of the ovarian cycle?
- The follicular phase, ovulation and the luteal phase.
- What are the three phases of the uterine (menstrual) cycle, in order?
- Menstrual phase, proliferative phase and secretory phase.
- Which hormone does the corpus luteum mainly secrete?
- Progesterone, along with some estrogen.