Created by J yadonknow
over 6 years ago
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Question | Answer |
Proliferation phase | Oestrogen secreted by developing follicle leads to growth + thickening of the endometrium Uterine glands develop in endo, don't secrete yet |
Secretory (progestational) phase | C.L. secretes pro + oestradiol Prog + uterine glands to produce uterine milk - high in pro + glycogen Provides correct environment should ovum fertilisation occur |
Menstrual phase - shedding | C.L. regresses no prog/o endo no longer maintained, necrosis occurs Expelled w blood as menstrual fluid |
Implantation delay | Fertilised ovum begins to divide, reaches uterus in 3/4 days gives time for endom to develop to a suitable state for imp. of developing blastocysts |
Day 9 what does the blast produce? | Developing blast produces hCG at high levels for 8 weeks |
Function of hCG | prevents C.L. from regressing |
How does fertilisation signal that it's taken place? | hCG signals CL to continue prog. secretion |
What's the false negative | hCG drops at 4 months, gives off false negative |
What takes over hCG secretion after this? | Placenta |
Placenta hormones (4) | hCG Progesterone oESTROGEN hPL |
hCG function | ensures continued secretion of progesterone in early pregnancy |
Progesterone function for 'metrium | Maintains endometrium decr. myometrial excitability |
Oestrogen in devo | Important for build up of uterine muscle + mammary development |
hPL | Human placental lactogen Secreted ~ 10 weeks into gestation Regulates foetal growth and co-ordinates foetal/maternal metabolism |
Partuirition is | Contraction of myometrium sufficiently strong enough to expel foetus |
Contractions + by: | High O:Prog |
Why? | Upregulates oxytocin R in myometrium Circulating oxytocin can bind + induce muscle contraction |
What else stims. contraction? (2) | Pressure of foetus against cervix PFF-2alpha |
example of? | Neuroendocrine reflex |
MOA | ^ Oxytocin secretion from P.P. Stronger contractions +FDBCK cycle progressively ^ until cervical dilation + delivery are completed. |
Synthetic oxytocin | Pitocin |
How does elevated PLACENTAL Og:Prog stim. lactation? | during gestation this stim. promotes development of ducts + alveoli in mammary glands |
Prolactin stim. | stim. synthesis of enzymes essential for milk production by alveolar epithelial cells |
What else stim lactation? | Withdrawal of placental steroids (removal of placenta) |
Suckling MOA (4) | Sustains lactation Triggers release of oxy/prolactin ox = milk ejection pro = milk synth. |
Hormone feedback suckling | suckling Mechanoreceptors in nipple Hypothalamus Nervous pathway / dopamine P.P. / A.P. ^ Oxytocin / ^ prolactin contraction / milk synth |
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