Human Reproduction

• Human reproduction


  The ability to produce new individuals
• Scrotum


  • Holds the testes outside the body at 35°C
• Testes


  • Produce sperm (gametes)
• Sperm duct


  • Transports sperm from testes

  
• Seminal fluid


  • Gives the sperm a medium to swim in and activates the sperm
  • Known as semen
• Urethra


  • Transports the semen out of the penis
• Puberty


  • Changes that take place in the body preparing for reproduction
  • Enlargement of testes and penis
  • Deepening of voice – larynx enlargement
  • Rapid growth spurt
  • Growth of hair on body
  • Widening of shoulders – more muscle
• Ovary


  • Produces eggs
• Fallopian tube


  • Where fertilisation takes place
• Uterus


  • Place where the baby develops

  
• Puberty in females


  • Widening of the pelvis
  • Enlarging of breasts
  • Growth of pubic hair
• Menstrual Cycle


  1. Ovulation: occurs on day 14 – release of an egg

  2. Fertile period: Time when the woman is most likely to conceive as the egg has been released

  
• Sexual Intercourse


  When the penis is inserted into the vagina and the semen (sperm and seminal fluid) are released at the base of the cervix
• Fertilisation


  When the sperm and the egg meet and fuse to form a zygote

  
• Gestation


  • Takes 9 months or 40 weeks
• Umbilical cord


  • Connects baby to the mother
• Placenta


  • Develops from the uterus lining and allows the mother and baby to exchange gases, nutrients, and wastes
  • The mother and babies blood never mix!
• Stages of Birth


  1. Uterus contractions

  2. Breaking of the waters

  3. Delivery of the baby

  4. Cutting of the umbilical cord

  5. Delivery of the placenta

  
• Contraception


  Preventing the egg and sperm from meeting
• Contraception methods


  • Pill
  • Condom
• Some may not believe in contraception due to religious or other reasons
• Different societies have different views on contraception
• IVF (In Vitro Fertilisation)


  Fertilising the egg and sperm outside of the body and implanting the fertilised egg in the uterus

  
• Some people feel IVF is not a natural process
• Not all embryos are used in IVF - some are destroyed or used for stem cell research
• IVF has an increased risk of birth defects
• Different societies have different views and laws on IVF
• Stem Cell Research


  • Stem cells can develop into any type of body cell
  • Research on such cells can help in treating such problems as Parkinson's disease, spinal injuries etc.
  • They can also be used to grow new organs for transplants
• Stem cells are used from fertilised cells left over from IVF
• The duty to prevent or reduce suffering
• The duty to respect the value of human life