Figure 12.15 shows some of the changes that occur throughout the phases of a menstrual cycle. For each of the physiological variables a–e below, select the most appropriate option from the following list of traces

 a. Option 3 Trace C. Oestrogens produced by the follicular cells of the developing ovum dominate the follicular phase of the cycle and peak about the time of ovulation; the level is still somewhat raised during the luteal phase.

b. Option 1 Trace A. Core temperature tends to rise about the time of ovulation and then falls again coming up to the following menstruation.

c. Option 4 Trace D. Luteinizing hormone secretion peaks at about the time of ovulation (in a similar manner to follicle-stimulating hormone, but its concentration tends to be greater).

d. Option 2 Trace B. Progestogens formed by the corpus luteum dominate the luteal phase of the cycle and cause the endometrium to enter the secretory phase.

e. Option 2 Trace B. Inhibin is a hormone produced by the ovary that inhibits secretion of follicle-stimulating hormone by the anterior pituitary gland. It peaks in the luteal phase of the cycle with a time course similar to the progestogen level.