Reproduction Flashcards
steps for fertilsation
• Preparing for fertilization o Capacitation o The acrosome reaction • Penetration of the zona pellucida • Fusion of the oocyte and sperm membranes • Egg activation o Corticol granule exocytosis o Resumption of the cell cycle • - Polar body is expelled
Brith:
when actions of progesterone dominate
uterus is quiet
prostaglandins inhibited
birth:
when actions of oestrogen dominate
uterus activated
prostaglandins synthesized
birth:
progesterone
need progesterone for pregnancy
wen progesterone low= termination of pregnancy occurs
birth:
glucocorticoids/cortisol
before birth, there is a cortisol surge (that can’t be overridden by negative feedback, and doesn’t need ACTH as well for cortisol to increase)
birth:
brown fat
has mito and does thermogeneniss (also has adrenergic nerve control to control thermogenesis )
birth:
before brith, what increases in foetus?
lecithin (byproduct of surfactant)
corticosteroids
liver glycogen (cos increase in cortisol causes increase of glycogenesis or sumthing)
progesterone
oestrogen
prolactin
cortisol surge
uterotrophic factors
prepare uterus for contraction
uterotonic factors
casue contractions in uterus:
prostaglandins in uterus
oxytocin from pituitary
uterotrophic and uterotonic factors inhibited by and potentiated by
inhibited by progesterone
potentiated by oestrogen
PGE2
act on cervix, can be used clinically to induce labour (given as a vaginal gel to soften cervix.
Ferguson reflex:
wen baby moves down further, stretches the wall, send signals to brain, release more oxytocin , =more contraction. positive feedback loop
oxytocin involved in ferguson reflex
what initiates birth in humans
the signals originate from inside the uterus- could be the baby or the uterine wall etc we dont really know
- Withdrawal of Progesterone action is necessary
- Prostaglandins is necessary
stages of labour
contractions & to full dilation of cervix
full dilation and baby delivered
placenta gotten rid of
wat prevents lactation
oestrogen!
endocrine control of lactation
during pregnancy: progesterone n oestrogen promote growth of ducts in breast. Prolactin contributes but its action is inhibited by sex steroids
at brith: progesterone and oestrogen conc fall massively
prolactin plataus at a medium level
lactation takes a few days to work
normal menstrual cycle is
28 days
normal range 21-35 days
phases of menstrual cycle
Follicular phase: variable length
Menstrual
Proliferative
Luteual phase: fixed length of 14 days
Secretorymenopause def
the last menstrual period in a woman who has
not had a hysterectomy
o Perimenopause def
time from the onset of cycle irregularity through until 12 months after the last menstrual period
o Premature ovarian insufficiency def
cessation of ovarian function occurring before age 40
menopause facts
The last menstrual bleed in a
woman with an intact uterus
Permanent loss of ovarian follicular
development
Loss of cyclical production of
estradiol, progesterone and
testosterone.
o Average age = 51.5 years
inhibin
• Produced by healthy Graafia follicles
ANTI-MULLTERIAN HORMONE (AMH)
• A product of growing follicles
indicator of ovarian reserve
the higher the AMH level, the greater the follicle population
low levels predict menopause coming
