Flashcards in hormonal control of reproduction Deck (21):
hormones are chemical messengers produced by
hormones are released directly into the bloodstream
and travel to their target tissue organ
hormones control the
the hypothalamus releases a hormone called
GRH- grande releasing hormone
pituitary gland releases 2 hormones
FSH- follicle stimulating hormone
ICSH- interstitial cell stimulating
promotes sperm production
stimulates the interstitial cells in the testes to produce the male sex hormone called testosterone.
sperm production in seminiferous tubules and activates the prostate gland and seminal vesicles to produce their fluid secretions.
overproduction of testosterone
prevented by a negative feedback mechanism
high testosterone levels inhibit the secretion of
FSH and ICSH from the pituitary gland, resulting in a decrease in the production of testosterone by interstitial cells.
how long the menstrual cycle takes
follicular phase , FSH stimulates the development and maturation of
a follicle surrounding the ovum and the production of the sex hormones
oestrogen stimulates the
repair and vascularisation of the endometrium, thicken it and preparing if for implantation
High levels of oestrogen stimulate the secretion
of LH by the pituitary gland.
In the luteal phase,a surge in LH triggers
ovulation and then stimulates the development of the corpus luteum from the follicle
LH also stimulates the
corpus luteum to secrete the sex hormone progesterone
progesterone promotes the further development and vascularisation
of the endometrium, preparing it for implantation of a blastocyst if fertilisation occurs.
high levels of oestrogen and progesterone inhibit the secretion
of FSH and LH by the pituitary gland, which prevents further follicles from developing
The inhibition of FSH and LH by high levels of oestrogen and progesterone is an example
of negative feedback control.
if fertilization does not occur:
there is a drop in LH levels, which causes the corpus luteum to break down , and also causes a decrease in progesterone and oestrogen levels