Q.Describe the changes that occur in the ovary and in the uterus during the follicular, ovulatory and luteal phases of the menstrual cycle, and explain how these changes are hormonally coordinated.
You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.
Start your 14-day free trial to unlock the full solution →In the follicular phase, rising FSH from the anterior pituitary stimulates a cohort of ovarian follicles to grow, one of which becomes the dominant, maturing Graafian follicle; the granulosa/theca cells of these growing follicles secrete increasing amounts of oestrogen, which acts on the uterus to make the endometrium regenerate and progressively thicken (the proliferative phase of the endometrium). As oestrogen from the now-mature follicle reaches a sufficiently high level, it switches the pituitary's usual negative feedback into positive feedback, producing a sharp mid-cycle LH surge (with a smaller FSH surge); this LH surge is the direct trigger for the brief ovulatory phase, in which the Graafian follicle ruptures and releases the secondary oocyte. In the luteal phase that follows, the ruptured follicle's remaining cells, still under LH influence, transform into the corpus luteum, which secretes large amounts of progesterone (with some oestrogen); progesterone converts the endometrium into a thick, glandular, highly vascular, secretory state, preparing it to support a blastocyst should implantation occur. If fertilisation does not take place, the corpus lu …
Unlock everything free for 14 days
- Full step-by-step solutions
- Concept-first explanations
- Methods, shortcuts & mistakes
- PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.