Final answer:
The claim that rising estrogen levels always inhibit release of FSH and LH is false; high estrogen levels can trigger a positive feedback loop leading to increased release of these hormones to induce ovulation.
Step-by-step explanation:
The statement that rising estrogen levels in the plasma exert negative feedback on the hypothalamus and anterior pituitary, inhibiting the release of FSH and LH, is generally false. In the regulation of the female reproductive cycle, initially, estrogen does exert negative feedback to inhibit FSH and LH release. However, when a dominant follicle remains, it secretes such high levels of estrogen that this eventually leads to a switch from negative to positive feedback, which actually stimulates the release of large amounts of LH and FSH from the anterior pituitary. This physiological mechanism is critical for triggering ovulation.
Hormone levels in both males and females are primarily controlled through negative feedback systems, where rising levels of a given hormone typically inhibit its further release. But in the case of the female reproductive cycle, very high concentrations of estrogen trigger a regulatory switch that overrides the typical negative feedback mechanism.