What hormone stimulates the anterior pituitary to secrete FSH and LH?

Gonadotropin releasing hormone (GnRH) is the hormone responsible for stimulating the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Released from the hypothalamus in a pulsatile fashion, GnRH travels to the anterior pituitary, where it binds to specific receptors, leading to the synthesis and release of FSH and LH. These hormones play pivotal roles in regulating the menstrual cycle, reproductive function, and ovarian activity in females, as well as spermatogenesis in males.

The other options mentioned function differently within the endocrine system. Estrogen is primarily produced in the ovaries and has multiple roles, including the regulation of the menstrual cycle and maintenance of secondary sexual characteristics, but it does not stimulate the anterior pituitary to release FSH and LH directly. Prolactin primarily plays a role in lactation and is not involved in the stimulation of FSH or LH secretion. Testosterone, produced by Leydig cells in the testes, influences male reproductive functions and secondary sexual characteristics but does not act directly on the anterior pituitary to induce the secretion of these gonadotropins.