Question 1: Define the term 'menstrual cycle'.

Answer: The series of changes in the female reproductive system that prepare the body for pregnancy, occurring approximately every 28 days.

Question 2: Name the primary hormones involved in regulating the menstrual cycle.

Answer: Follicle-stimulating hormone (FSH), luteinising hormone (LH), oestrogen, and progesterone.

Question 1: Describe the role of FSH and LH in the menstrual cycle.

Answer: FSH stimulates follicle development and oestrogen production; LH triggers ovulation and stimulates the formation of the corpus luteum.

Question 2: Explain how levels of oestrogen and progesterone change during the cycle and their effects.

Answer: Oestrogen levels rise during the follicular phase, leading to thickening of the endometrial lining and a surge that triggers ovulation. Progesterone levels increase after ovulation, maintaining the endometrial lining; if pregnancy does not occur, both hormones fall, leading to menstruation.

Question 1: A woman’s menstrual cycle lasts 28 days. If ovulation occurs on day 14, calculate the number of days the corpus luteum remains active if pregnancy occurs.

Answer: Approximately 14 days (from day 14 to day 28).

Question 2: Using the formula: Cycle length = Follicular phase + Luteal phase. If the follicular phase is 14 days, what is the length of the luteal phase?

Answer: 14 days.

Question 1: Describe how hormone therapy can be used to regulate the menstrual cycle in women with irregular periods.

Answer: Hormone therapy, such as administering synthetic oestrogen or progesterone, can help regulate hormonal levels, induce ovulation, or prevent menstruation in women with irregular cycles, thereby restoring regular cycle patterns.

Question 2: Identify potential safety precautions to consider when using hormonal contraceptives that influence the menstrual cycle.

Answer: Monitoring for side effects such as blood clots, hormonal imbalances, and adverse reactions; ensuring proper dosage; and considering individual health conditions before use.

Question 1: In a clinical trial, 50 women taking a new hormone-based contraceptive reported the following side effects: 10 experienced mood swings, 5 reported headaches, and 3 experienced nausea. Calculate the percentage of women affected by each side effect.

Answer: Mood swings: 20%, headaches: 10%, nausea: 6%.

Question 2: Based on the data, discuss the potential benefits and drawbacks of using hormonal contraceptives.

Answer: Benefits include effective contraception and regulation of menstrual cycles; drawbacks may involve side effects such as mood swings, headaches, and nausea, which can affect quality of life and adherence to therapy.

Question 1: Explain the hormonal feedback mechanisms involved in the regulation of the menstrual cycle. (6 marks)

Answer: The menstrual cycle is regulated by a feedback loop involving the hypothalamus, pituitary gland, and ovaries. The hypothalamus releases GnRH, stimulating the pituitary to secrete FSH and LH. FSH promotes follicle development and oestrogen production, which provides positive feedback to increase LH secretion. The LH surge triggers ovulation. After ovulation, the corpus luteum secretes progesterone, maintaining the endometrial lining. High levels of progesterone and oestrogen inhibit GnRH, FSH, and LH secretion, completing the feedback loop.