Reproduction

• Stages in the life cycle

  1. The foetus grows in the womb

  2. A baby is born, learns to hold head up, sit, crawl, say words

  3. Toddler learns to walk, run, say 100 words

  4. Childhood starts at age 3, learn new skills like reading

  5. Early adolescence (10-14), reproductive system begins to develop (puberty)

  6. Late adolescence (15-18), body almost fully developed

  7. Adulthood (19-39), body fully developed

  8. Middle age (40-60), ageing begins to show

  9. Old age, adults get older, shorter, weaker
• Sexual characteristics


  Physical differences between men and women
• Types of sexual characteristics

  • Primary sexual: Differences between male and female reproductive organs
  • Secondary sexual: Other physical differences between men and women, e.g. women have wider hips, men have more body hair
• Sexual characteristics appear during puberty
• Puberty


  Time in life when a boy or girl becomes sexually mature, usually between ages 10-16 for girls and 12-16 for boys
• Puberty in girls


  1. Breasts begin to develop

  2. Pubic and armpit hair grows

  3. Girls grow taller and fill out

  4. Skin and scalp produce more oil, can cause acne

  5. Menstruation typically starts between 10-15 years old
• Puberty in boys


  1. Pubic hair begins to grow, also on face and under arms

  2. Voice deepens

  3. Boys become taller and heavier

  4. Skin becomes coarse and can be oily or develop acne

  5. Testicles enlarge and scrotum becomes larger and coarser

  6. Penis grows and boys become fertile
• Sperm cell


  Has an oval shape and a tail that allows it to move up the female's fallopian tubes and fertilise the ovum
• Parts of the male reproductive system

  • Testicles produce and store sperm
  • Vasa deferentia transport sperm to seminal vesicles
  • Seminal vesicles produce liquid that forms part of semen
  • Prostate produces liquid that forms part of semen
  • Penis contains urethra for sperm and urine to exit
• Female reproductive organs


  • Ovaries produce ova
  • Fallopian tubes connect ovaries to uterus
  • Uterus is organ with muscular walls where fetus develops
  • Cervix is part of uterus that leads to vagina
  • Vagina is muscular tube connecting uterus to outside
  • Vulva covers opening to vagina
• Menstruation


  1. Ovaries release ova about every 28 days (ovulation)

  2. Uterus lining thickens in preparation for fertilisation

  3. If no fertilisation, ovum dries up and leaves body through vagina

  4. Thickened uterus lining also comes away, causing menstrual bleeding
• Menstruation typically lasts 3-5 days and continues until menopause around age 50
• Human reproduction


  Involves a female ovum and a male sperm, each carrying different genetic information so children are unique
• Differences between male and female reproductive systems

  • Male system designed to produce and deliver sperm
  • Female system designed to produce ova, house and nourish developing fetus
• Steps of pregnancy


  1. Fertilisation: Sperm fertilises ovum in fallopian tube

  2. Embryo development: Zygote travels to uterus, cells divide and multiply

  3. Fetus development: Embryo fixes to uterus lining, organs form, fetus floats in amniotic fluid

  4. Birth: Fetus pushes against cervix, which opens, uterus contracts to push baby through birth canal
• Ovum


  Female sex cell
• Sperm


  Male sex cell
• Children are unique as they have genetic code from both parents
• Male reproductive system


  • Designed to produce and deliver sperm
• Female reproductive system


  • Designed to produce ova, as well as housing, nourishing and protecting a developing foetus
• Pregnancy


  1. Fertilisation

  2. Development of the embryo

  3. Development of the foetus

  4. Birth
• Fertilisation


  1. Ovum is released into the fallopian tubes

  2. Sperm are deposited in the vagina

  3. Sperm swim up to the ovum

  4. Ovum is fertilised

  5. Cells start to divide and multiply to form a zygote
• Development of the embryo

  1. Zygote travels to the uterus

  2. Cells continue dividing and multiplying

  3. Embryo fixes itself onto the lining of the uterus
• Development of the foetus

  1. Embryo develops into a foetus

  2. Foetus floats in amniotic fluid

  3. Foetus receives oxygen and nourishment from the mother's placenta

  4. Waste and carbon dioxide transferred from foetus to mother via placenta

  5. Foetus connected to placenta by umbilical cord
• Birth


  1. Foetus pushes against the cervix

  2. Cervix opens and widens

  3. Amniotic fluid is released

  4. Uterus muscles contract

  5. Foetus passes through cervix and birth canal

  6. Umbilical cord comes out with baby

  7. Umbilical cord is cut and tied

  8. Placenta comes out after baby
• The four steps of pregnancy:

  1. Fertilisation:

  Fertilisation of the ovum can occur after the egg is released into the fallopian tubes.

  During sexual intercourse the man ́s penis is inserted into the woman ́s vagina, and