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Answer either A or B in the space below - Scottish Highers Human Biology - Question 14 - 2015
Question 14
Answer either A or B in the space below. Labelled diagrams may be used where appropriate. A Describe hormonal control of the menstrual cycle under the following he... show full transcript
Worked Solution & Example Answer:Answer either A or B in the space below - Scottish Highers Human Biology - Question 14 - 2015
Step 1
events leading to ovulation
Answer
- The hypothalamus releases Gonadotropin-releasing hormone (GnRH), stimulating the anterior pituitary.
- The anterior pituitary secretes Follicle Stimulating Hormone (FSH), promoting the maturation of ovarian follicles.
- The developing follicles produce estrogen, which is crucial for the regulation of the menstrual cycle.
- As the estrogen levels rise, they stimulate the release of Luteinizing Hormone (LH) through positive feedback mechanisms.
- The surge in LH triggers ovulation, resulting in the release of the oocyte from the dominant follicle.
- Increased levels of estrogen further inhibit FSH production through negative feedback.
Step 2
events following ovulation
Answer
- After ovulation, the ruptured follicle transforms into the corpus luteum.
- The corpus luteum secretes progesterone and estrogen to prepare the uterus for potential implantation of a fertilized egg.
- Progesterone maintains and thickens the endometrium, providing a suitable environment for a fertilized egg.
- If fertilization does not occur, the corpus luteum degenerates and hormone levels decrease, leading to menstruation as the endometrial lining is shed.