Final answer:
The statement in the question is false; no body parts are replaced during the menstrual cycle. The menstrual cycle involves hormonal changes, and the endometrium is shed during menstruation. Hormones from the hypothalamus, pituitary gland, and ovaries regulate these processes.
Step-by-step explanation:
The assertion that as the last phase of menstruation finishes in one ovary, one body part is replaced by a body part normally found in another region is false. During the menstrual cycle, no body parts are replaced or transposed; rather, there are hormonal changes and cyclical transformations within the structures of the female reproductive system.
Menstruation is the part of the menstrual cycle when the inner lining of the uterus, known as the endometrium, is shed. This is not a replacement of one body part with another, but a natural process of the cycle coinciding with the follicular phase of the ovarian cycle. Day 1 of the menstrual cycle marks the beginning of menstruation, not the release of a secondary oocyte. The secretory phase in the uterine cycle generally aligns with the luteal phase of the ovarian cycle, where the endometrium prepares for potential implantation of a fertilized egg.
Hormones from the hypothalamus, pituitary gland, and ovaries regulate the menstrual cycle. During the ovarian cycle, rising levels of follicle-stimulating hormone (FSH) stimulate the growth of ovarian follicles. The follicles release estrogen, which causes the endometrium to thicken in preparation for a potential pregnancy. If fertilization does not occur, the corpus luteum degrades, progesterone production decreases, and menstruation begins with the sloughing off of the endometrium.