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MVST 1B (Fach) / HR (Lektion)
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- Structure of hormones Gonadotrophs Luteinising hormone [LH]: 92/120 Follicle stimulating hormone [FSH]: 92/111 [Progesterone] Placental hormones human chorionic gonadotrophin [hCG]: 92/145 placental lactogen -- human chorionic somatomammatropin placenal gorowth factor α-subunits of glycoproteins LH, FSH, TSH, hGC identical β-subunits confer function
- Contraceptive pill Combined: prevent ovulation, negative feedback on GnRH Progesterone-only: thicken cervical mucus, ↓ sperm viability & penetration; inhibition of ovulation at higher concentration Mifepristone: antiprogestogen → inhibits maintenance
- Chorion laeve Doesn't form placenta; adjacent to decidua capsularis (→basalis, parietalis)
- Velamentous insertion Umbilical chord inserting into the chorion laeve, then travelling to the placenta between the chorion and the amnion.
- Fertilization Sperm activation (progesterone from cumuls cells, ZP3 binding) Acrosome reaction → hyaluronidase → dislodging of cumulus cells Whiplash tail movement Cortical reaction cleave ZP2, ZP3 less effecive in post-ovulatory aged oocytes Activation of the ovum 4hrs → syngamy Contribution of sperm Parthenogenesis & imprinting
- Implantation central vs interstital (10d post-fertilization) Oestrogen → LIF from uterine glands → LIF receptor Progesterone → MUC-1 HB-EGF, HSPG etc
- Structure of the placenta ??
- Fecundity Women onset: puberty (menarche, not growth spurt) end: menopause -- ovarian decline & failure → 2ary amenorrhoea Men onset: puberty (testis) end: andropause (CV, erectile dysfunction, ...)
- Transport across placenta Passive diffusion: glucose, ribose ?? Facilitated diffusion Active transport Receptor-mediated
- Fetal nutrients Glucose - 35-45 Lactate - <10 AA's - 2-4 via urea production oxygen - 300 μmol/min/kg
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- Bilirubin metabolism ??
- Maternal cardiovascular changes blood volume +40% in first two trimesters; due to ↑RAAS haemodilution, but increased RBC's, clotting factors increased, SV & HR, no increase in BP; decreased TPR → pre-ecclampsia?
- Maternal adaptations endocrine physiological physical cardiovascular renal respiratory metabolic behavioural
- Parturition Fetal cortisol, PGF-2a
- Lactation Mammogenesis duct system: adrenal steroids, oestrone,GH alveolar system: P, O, PL, adr roids, GH milk synthesis & secretion Lactogenesis: onset of milk production; oestrogen/progesterone withdrawal; fully developed breast Galactopoiesis: suckling → prolactin / lactogenic complex Lactokinesis: milk ejection, suckling oxytocin lactational contraception via GnRH inhibition by suckling bromocriptine to inhibit lactogenesis
- Placental peptide hormones chorionic gonadotrophin recognition of pregnancy, maintains corpus luteum via LH receptors fetal testis → testosterone release placental lactogen ~ growth hormone (96%), prolactin (67%) lipolysis, maternal FFA mobilisation antagonises peripheral insulin differentiation of mammary glandular tissue placental growth hormone ~ growth hormone growth promoting effect regulates maternal IGF-1 levels
- Placental steroid hormones Progesterone after 1st trimester, taken over from corpus luteum Oestrogens can't use cholesterol DHAS from fetal/maternal adrenals → oestradiol, oestrone 16-OH DHAS from fetal liver → → oestriol (90%, fetal well being)