Role of Hormones (to Do) Flashcards
what hormones maintain uterine quiescence
progesterone
relaxin
nitric oxide
do systemic plasma levels represent local hormone changes?
No
describe changes that cause activation of mymometrial cells
increased oestrogen : progesterone ratio
(oestrogen facilitates contractions, progesterone inhibits)
what hormones ripen cervix
prostaglandins
relaxin
nitric oxide
when does myometrium respond to prostaglandins and oxytocin
when myometrial cells are activated (O>P)
Cervix is ripe
HcG
where is it secreted from
when can it be detected
function
what does high HcG indicate / cause
human chorionic gonadotrophin
secreted from - trophoblast
detected blood (day 9), urine (10-12) post fertilisation
Role
- prevents degeneration of Corpus luteum + stimulates CL to secrete oestrogen + progesterone
- influence change in smell / taste / saliva
- may have immunosuppresant role (so maternal body doesn’t reject placenta)
high hcg may indicate molar pregnancy / hyperemesis
Oestrogen - in reproduction cycle
type of oestrogen
what secretes this hormone
who synthesizes oestrogen
what are functions (in reproductive cycle + pregnancy)
Secreted
-by follicle cells in ovaries
- Corpus luteum (until wk 7)
- placenta
type- ostradiol
stimulated by
FSH (mainly) + LH
Function
reproductive cycle
- develo and maintain female reporductive structures
- maintaining fluid / electrolyte balance
Oestrogen- in pregnancy
what secretes this hormone
who synthesizes oestrogen
what are functions
Secreted
- Corpus luteum (until wk 7)
- placenta
type- oestriol (oestradiol is main source in non-pregnancy)
synthesis
- synthesized from woman, fetus, placenta
Function
overall- role is to stimulate tissue growth
* -uterus- hyperplasia +hypertrophy + vascularisation
* breast development
* swelling + softening of connective tissue (symphysis pubis dysfunction, ligament pain)
* fluid retention
also
increase uterus’s sensitivity to progesterone
increase sensitivity to CO2
Progesterone - in pregnancy
where is it secreted
how is it synthesized
Functions and amount in pregnancy
change in labour
secreted from- Corpus luteum (<7wks), placenta
Synthesis is NOT reliant on fetal dev
functions
1) stimulates Decidua secretions (support early implantation)
2) RELAXES smooth muscle
* `uterine contractions
* ureters (stasis), * stomach (nausea + vomiting) + intestines (constipation), osophogeal sphincter (heartburn), reduced peripheral resistance (haemorrhoids + varicose veins, postural hypotension)
3) stimulates ventilation at lower PaCO2 (increases sensitivity of maternal chemoreceptors) (thus can stimulate hyperventilation)
4) suppreses immunological response
5) precursor to fetal adrenal hormone
6) increases body temp
Amount
increases throughout pregnancy. Drop rapidly after placenta removed
labour
- in labour, oestrogen > progesterone (enabling cx of uterine muscle)
Progesterone (non-pregnancy)
where is it secreted
how is it synthesized
Functions and amount in pregnancy
change in labour
secreted from- Corpus luteum
stimulated by LH
functions
- prepare endometrum to receive fertilised ovum
- prevent sperm motility (thicken mucous)
- increse body temp
- relax fallopian tube muscles to support ovum passage to uterus
Amount
peak post ovulation
GnRH
where is is produced?
function
what hormones inhibit GnRh
produced by hypothalamus
function
- Stimulates Anterior pituitary gland to release FSH + LH
Inhibited by
oestrogen + progesterone
prolactin can inhibit GnRH (lactational amenorrhea)
prolactin
function
where is it secreted
what inhibits it
function-
- Antenatally- development of mammary glands
- lactation (lactogenesis II)
secreted from - APG (stimulated by nipple stimulation)
inhibited by
- Antenatally- Progesterone, human placental lactogen, prolactin inhibiting factor (from hypothalamus) inhibit prolactin from binding to receptors (inhibits lactogenesis)
Positive Feedback
levels
- increase in pregnancy- surge at birth and reduce after 6 weeks in BF women
Lutenising hormone
where is it secreted from
function
inhibited by
LH
secreted from APG
stimulated by GnRH
Function
act on thecal cells- iinhibit FSH
FSH
Follicle stimulating hormone
function
- develop follicles in ovary as part of ovarian cycle
-
what triggers ovulation
LH surge