4.4 Lesson 4: Reproductive Hormones

Ovaries

Paired organs in human females that produce gametes (eggs) as well as estrogens and progestins.

Estrogens

Steroid hormones, such as estradiol, responsible for the changes occurring during puberty in females.

Progestins

Steroid hormones such as progesterone, responsible for maintaining the uterus for fertilization.

Follicle-stimulating hormone (FSH)

A hormone released from the pituitary gland that stimulates oocytes to begin meiosis.

Luteinizing hormone (LH)

A hormone from the pituitary gland that triggers ovulation and the formation of the corpus luteum.

Gonadotropin-releasing hormone (GnRH)

Hormone released from the hypothalamus that controls the release of FSH and LH.

Negative feedback mechanism

A process that regulates the continued release of hormones in the reproductive system.

Ovarian cycle

A series of events in the ovaries leading to the release of a mature egg approximately every 28 days.

Follicular phase

The initial phase of the ovarian cycle where oocytes begin meiosis and develop follicles.

Ovulation

The release of a mature egg from the follicle triggered by a burst in LH production.

Corpus luteum

A structure formed from enlarged ovarian cells post-ovulation that secretes estrogen and progestin.

Luteal phase

Phase following ovulation where the corpus luteum functions and prepares the uterus for fertilization.

Human chorionic gonadotropin (hCG)

Hormone released by implanted embryo that prevents the shrinking of the corpus luteum.

Testes

Paired organs in human males that secrete androgens, including testosterone.

Androgens

Steroid hormones such as testosterone, which stimulate male reproductive system development.

Spermatogenesis

The process of sperm cell production from precursor cells called spermatogonia.

Sertoli cells

Cells in the testes that are stimulated by FSH to secrete proteins for spermatogenesis.

Leydig cells

Cells in the testes stimulated by LH to secrete testosterone.

Anabolic steroids

Synthetic steroids that mimic testosterone to build muscle mass, but have negative side effects.