sex hormones 1&2 Flashcards
what are sex hormones?
they are all steroid hormones
how are sex hormones synthesized?
by cholesterol
are male and female hormones present in both genders?
yes in all adults
the female body contains lower levels of testosterone and other androgen
the male body contains low levels of oestrogen
what are the male sex homrones?
androgens
testosterone the primary male sex hormone is an androgen
what produces testosterone?
mainly leydig cells of the testes and to a lesser extend the adrenal glands produce testosterone and other androgen
when do leydig cells become active?
after birth they become quiescent until activated by gonadropins during puberty
at puberty androgens cause the sex hormones to grow and cause secondary characteristics to develop
how does testosterone get secreted/produced?
hypothalamus secretes GnRH
GnRH goes via hypothalamo-pituitary portal vesseks
the anterior pituitary secretes FSH and LH
LH caueses leydig cells to produce testosterone
FSH causes sertoli cells to stimulate speromatogenesis
sertoli cells produce inhibin with produces a negative feedback only on FSH
tesosterone produces a negative feedback on LH and GnRH
What stimulates erythropoietin secretion by the kidneys?
testosterone
what are the dominant female sex hormones?
oestrogen and progesterone- produced by the ovaries
when is hormone production low in females?
during foetal development, infancy and childhood
at puberty it is high- sexual development
when are these female sex hormones at the highest?
these hormones are produced in higher level during pregnancy
how and why is andorgen produced in females?
androgen are produced in small amounts by the ovaries and adrenals and also have important functions in women
what are some of the other effects of oestrogen?
stimulates growth of ovary follices
stimulates growth of smooth musle and proliferation of epithelial linings of preproductive tract
stimulates external genitalia growth
stim breast growth
sexual development
stim fluid sex from lipid producing skin glands
stim bone growth and ultimate cessation of bone growth
vascular effects
has feedback on hypothalamus and anterior pituitary gland
stimulayes prolactin secretion but inhibits prolactin’s producing milk-inducing action on the breasts
protects against atherosclerosis by effects on plasma cholesterol, blood vessels and blood clotting
what are the other effects of progesterone?
converts oestrogen- ready for inplantation
induces thick, sticky cervical mucus
decreases contraction of fallopian tubes and myometrium
decreases proliferation of vaginal epithelial cells
stimulates breast growth, particularly glandurlar tissue
inhibits milk inducing effects of prolactin
has feedback effects on hypothalamus and anterior pituitary
increases body tem
how does the female reporoductive system work?
hypothalamus secretes GnRH -
anterior pit releases FSH AND LH
this stimulates ovaries to produce oestorgen and testosterone
what role does FSH have in the female reproductive cycle?
ovarian follicel matures and secretes oestrogen
uterine lining thickens
what role does LH have in the female reporductive system?
triggers ovulation
the follicular cells become corpus luteum which secretes progesterone
lining more vascular and glandular
what are the different types of contraception?
coitus interrupts rhythm method- absense at ovulation mechanical barriers chemical barriers oral/injectible/insertable contraceptives contraceptive implants transdermal contraceptives IUD surgical method
what are some of the advantages of COC?
reliable and reversible
reduced dysmenorrhoea and menorrhagia
reduced indidenced of premenstrual tension
less symptomatic fibroids and functional ovarian cysts
less benign breast disease
reduced risk of ovarian and endometrial cancer
reduced risk of pelvic inflamatory disease
what is a monophasic COC?
fixed amount of an oestrogen and a progestogen in each active tablet
what is a bi/tri/quadraphasic COC?
varying amounts of the two hormones according to the stage of the cycle
what are the two types of oestrogen used in combined ?
ethinyl estadiol and mestranol
what is mestranol?
it is a prodrug that is converted in vivo to ethinyl estradiol
what is the usual oestrogen content of ethinylestradiol?
20-35ug