reproduction

• Sperm cells


  Male reproductive cells
• Fertilisation


  Nucleus of sperm cell fuses with nucleus of egg cell
• Sperm cells


  • Have a flagella that helps them travel to the egg cell
  • Have a streamlined shape that allows them to swim towards the egg
• Testes


  Produce sperm cells
• Egg cells


  Female reproductive cells
• Ovulation


  After puberty, egg cells start to develop and one is released every 28-32 days
• Oviducts (fallopian tubes)


  • Lined with hairs called cilia that sweep egg cells towards the uterus
• Uterus


  Where the baby develops during pregnancy
• Cervix


  Opening to the vagina that holds the baby in place during pregnancy
• Fertilisation


  1. Occurs in the oviduct (fallopian tube)

  2. Fusion of the nucleus of the sperm and the nucleus of the egg cell
• Implantation


  The embryo implants into the uterus wall
• Zygote


  Formed after fertilisation
• Embryo development


  Zygote develops into an embryo through cell division
• Placenta


  Where oxygen, water and food from the mother's blood goes into the embryo's blood
• Umbilical cord


  Carries the embryo's blood to and from the placenta
• Pregnancy stages


  Zygote -> Embryo -> Fetus
• Labour


  When the baby is ready to be born, the uterus begins to contract
• Puberty


  Process where physical changes happen to both boys and girls, started by sex hormones
• Puberty starts between the ages of 10-14
• Testosterone


  Male sex hormone
• Estrogen


  Female sex hormone
• Progesterone


  Female sex hormone
• Changes in girls during puberty

  • Hair growing under arms
  • Pubic hair growing
  • Hips get wider
  • Ovaries start releasing egg cells
  • Breast development
• Changes in boys during puberty

  • Hair growing under arms, face and chest
  • Pubic hair growing
  • Testes start making sperm cells
  • Voice deepening (breaks)
• Menstrual cycle


  Lasts about 28-32 days
• Menstruation


  Soft lining of the uterus breaks apart and sheds, passing out the vagina along with blood and an unfertilised egg cell
• Ovulation


  1. After menstruation, an egg cell starts to mature in an ovary

  2. The lining of the uterus starts to build up to develop a network of blood vessels

  3. After 14 days, the egg cell is released from the ovary
• amniotic fluid

  protects the foetus from temprature changes
• alcohol and drugs can go through the placenta and harm the foetus
• during labor, the walls of the uterus contracts and relaxes to push the baby out
• harmful substances such as alcohol, passes from the mother's blood to the baby's blood through the placenta
• eggs are released in the female reproductive system every 28 days / every month
• the uterus lining breaks up from day 1-5 of the menstruation cycle, it passes out the vagina along with blood and an unfertilised egg cell
• the lining of the uterus builds up between day 5-14 allowing the embryo to implant successfully and receive nutrients