How can we help?

You can also find more resources in our Help Center.

36 terms

CH 28 - Reproductive Hormones

STUDY
PLAY
inhibin
inhibits production of FSH by the anterior pituitary gland
LH
stimulates Leydig cells to secrete testosterone in males and triggers ovulation in females
FSH
stimulates the initial secretion of estrogens by growing follicles; promotes follicle growth
testosterone
stimulates male pattern of development; stimulates protein synthesis; contributes to sex drive
estrogens
promotes development of female reproductive structures; lowers blood cholesterol
progesterone
is secreted by the corpus luteum to maintain the uterine lining during the first trimester of pregnancy
relaxin
relaxes the uterus by inhibiting myometrial contractions during monthly cycles; increases flexibility of the pubic symphysis during childbirth
human chorionic gonadotropin
maintains the corpus luteum during the first trimester of pregnancy
prolactin
anterior pituitary hormone that stimulates milk production
oxytocin
posterior pituitary hormone responsible for uterine contraction and release of milk from mammary glands
androgens
contribute to male sexual behavior, spermatogenesis, and libido; adrenal cortex is the main source of this hormone in females
dihydrotestosterone
stimulates male external genital development
gonadotropin-releasing hormone (GnRH)
hypothalamic neurosecretory cells increase their secretion of this hormone, which in turn stimulates gonadotrophs in the anterior pituitary to increase their secretion of the two gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
LH
synthesized from cholesterol in the testes and is the principal androgen
LH
is lipid-soluble and readily diffuses out of Leydig cells into the interstitial fluid and then into blood
testosterone
suppresses secretion of LH by anterior pituitary gonadotrophs and suppresses secretion of GnRH by hypothalamic neurosecretory cells
dihydrotestosterone (DHT)
in the external genitals and prostate, the enzyme 5 alpha-reductase converts testosterone into this hormone
FSH
this hormone in addition to testosterone, act synergistically on the Sertoli cells to stimulate secretion of androgen-binding protein (ABP) into the lumen of the seminiferous tubules and into the interstitial fluid around the spermatogenic cells
androgen-binding protein (ABP)
binds to testosterone, keeping its concentration high
Testosterone-dihydrotestosterone androgen receptor complex
hormone-receptor complex regulates gene expression,
turning some genes on and others off
testosterone
stimulates the male pattern of development of reproductive system ducts and the descent of the testes before birth
testosterone
converted in the brain to estrogens (feminizing hormones), which may play a role in the development of certain regions of the brain in males
testosterone and dihydrotestosterone
bring about development and enlargement of the male sex organs and the development of masculine secondary sexual characteristics at puberty
androgens
are anabolic hormones; they stimulate protein synthesis
Gonadotropin-releasing hormone (GnRH)
secreted by the hypothalamus controls the ovarian and uterine cycles
FSH
initiates follicular growth
LH
stimulates further development of the ovarian follicles; stimulates the theca cells of a developing follicle to produce
androgens
FSH and LH
stimulate the ovarian follicles to secrete estrogens
androgens
are taken up by the granulosa cells of the follicle and then converted into estrogens
LH
triggers ovulation and then promotes formation of the corpus luteum
corpus luteum
produces and secretes estrogens, progesterone, relaxin, and inhibin
estrogens
promote the development and maintenance of female reproductive structures, secondary sex characteristics, and the breasts
estrogens
increase protein anabolism; are synergistic with human growth hormone
estrogens
lower blood cholesterol level
estrogens
inhibit both the release of GnRH by the hypothalamus and secretion of LH and FSH by the anterior pituitary
Progesterone
cooperates with estrogens to prepare and maintain the endometrium for implantation of a fertilized ovum and to prepare the mammary glands for milk secretion; high levels inhibit GnRH and LH