hormones during pregnancy and birth

• what is secreted by the embryo just before and after implantation during pregnancy

  HCG
• what is the function of HCG

  maintains corpus luteum for the first 16 weeks of pregnancy
• what does the rise of progesterone and oestrogen from the placenta suppress

  the secretion of FSH and LH
• what does FSH need to be supressed by the placenta


  so that no more follicles develop
• what does LH need to be supressed by the placenta


  so no ovulation takes palce
• what is the function of progesterone in the placenta

  this is to supress the uterine walls ability to contact and maintains the endometrium
• what is the function of oestrogen in the placenta

  this is to stimulate the growth of the uterus to accommodate the growing feus and stimulate the growth and development of the mammary gland
• what happens just before birth in terms of hormones

  oestrogen levels increase and progesterone levels decrease
• what does the rise in oestrogen and decrease in progesterone mean

  the uterine wall can now contract
• where is oxytocin secreted

  by the posterior pituitary gland
• what is the function of oxytocin

  it stimulates the contraction of the myometrium
• what is the myometrium

  muscle layer in the wall of the uterus
• what do the contractions caused by oxytocin stimulate


  more oxytocin to be released
• what is oxytocin leading to more oxytocin being produced an example of

  positive feedback
• what happens as oxytocin levels increase


  the contractions become stronger and more frequent
• what hormone is released from the anterior lobe of the pituitary gland during and after birth

  prolactin
• what is the function of prolactin

  this stimulates the production of milk by the mammary glands
• what glands produce milk

  mammary glands