Human reproduction

• Reproductive hormones are release when puberty starts
• Testosterone is the main male reproductive hormone it stimulates sperm production and is released by the testes
• Oestrogen is the main female reproductive hormone and is released by the ovaries
• Secondary sex characteristics are features that appear during puberty
• The four hormones which control the menstrual cycle in females

  FSH

  oestrogen

  LH

  progesterone
• FSH


  released by the pituitary gland

  Causes and egg to mature in an ovary
• Oaestrogen

  Produced when egg matures

  Causes lining of uterus to thicken
• LH


  released by the pituitary gland

  Makes ovary release the egg into the oviduct (fallopian tube)

  This is called ovulation
• Progesterone


  produced by ovaries after ovulation

  Maintains the lining of the uterus an keeps it intact

  If egg isn’t fertilised progesterone levels fall

  Causes uterus to shed its lining which is a period
• Menstrual cycle repeats roughly every 28 days
• Oestrogen stops the pituitary gland from releasing FSH so other eggs don’t start to mature
• Oestrogen also cases the pituitary gland to release LH which causes ovulation, ovulation causes the ovaries to release more progesterone
• Progesterone prepares the body for pregnancy by maintaining the lining of the uterus and helps to stop the production of more FSH and LH
• hormonal contraceptives prevent pregnancy by interfering with the menstrual cycle
• Some oral contraceptives(pills) contain oestrogen and progesterone to stop the production of FSH so it can’t cause an egg to mature
• Hormonal contraception


  Pill

  Injections

  Implants

  Skin patches

  IUD
• barrier methods of contraception


  Condoms

  Diaphragms
• Natural methods of contraception


  ovulation tracking

  Not having sex
• Surgical methods of contraception

  Vasectomy

  Having tubes tied
• Pro to condoms is that they protect against STIs

  Con is that they can be unreliable
• Pros to IUD injection and imolars is that they’re very reliable

  Cons don’t protect against STIs
• IVF


  women takes FSH and LH causes several of her eggs to mature at once

  Then have surgery to remove eggs

  Eggs are fertilised in a laboratory using sperm from a male

  Fertilised eggs develop into embryos

  One or two of these are inserted into the women’s uterus
• Cons to IVF


  physically and emotionally stressful

  Low rate of success

  Sometimes results in development of multiple babies