EXSS256 Reproductive Hormones

reproductive endocrinology

medical subspecialty within gynecology and obstetrics that addresses hormonal function as it pertains to reproduction as well as the issue of infertility

HPG (hypothalamus-pituitary-gonad) axis

a sequence of hormone production originating in the hypothalamus and moving to the pituitary and then to the gonads

HPG in males

regulates the production of sperm

HPG in females

regulates ovulation, ovarian cycle, and uterine cycle

male reproductive physiology

-Testes are the gonads where sperm production (spermatogenesis) takes place.

-Spermatogenesis occurs across the seminiferous tubules and results in the formation of mature sperm or spermatozoa.

-The seminiferous tubules are formed by Sertoli cells and surrounded by interstitial cells or Leydig cells.

-The seminiferous tubules drain into the epididymis where sperm maturation and storage occurs.

-Then are passed through the male duct system where secretions from the seminal vesicles, the bulbourethral glands and prostate gland enter this duct system. These fluids along with the sperm form the semen, which exits the body during ejaculation.

what controls reproductive physiology

hypothalamus

what is the goal of male reproductive physiology

to regulate sperm production

Spermatogenesis

production of sperm

step one of spermatogenesis

hypothalamus release gonadotropin releasing hormone to anterior pituitary

step 2 of spermatogenesis

anterior pituitary releases follicle stimulating hormone and luteinizing hormone

What does FSH stimulate?

Sertoli cells to secrete androgen-binding protein (ABP)

What does LH stimulate?

leydig cells to produce testosterone

female reproductive cycle

Encompasses ovarian and uterine cycle, hormonal changes that regulate them, and related changes in breast and cervix

what controls female reproductive cycle

monthly hormone cycle of anterior pituitary, hypothalamus, and ovary

menstrual cycle phases

follicular phase, ovulation, luteal phase, menstruation

follicular phase of menstrual cycle

GnRH secretion stimulates FSH and LH secretion, which promotes follicle development. Estrogen is released, stimulating vascularization and glandularization of the decidua

ovulation phase

The second stage of the general menstrual cycle, when the ovum is released.

luteal phase

period of corpus luteum activity (days 14-28)

menstruation phase

endometrial lining sheds

what does FSH stimulate in females

ovarian follicle development and secretion of estrogens

what does LH stimulate in females

secretion of estrogen and progesterone, ovulation, formation of corpus luteum