Human Reproduction

• Reproductive systems


  Systems that produce male and female gametes (egg and sperm) and allow fertilization and development of a new human being
• Menstrual cycle


  Female monthly cycle that releases an egg and the endometrium is shed
• Menstrual cycle


  1. Day 1: Menstruation occurs, Graafian follicle begins to develop

  2. Days 5-13: Follicle ripens, releases oestrogen

  3. Day 14: Mature egg released from ovary (ovulation)

  4. Days 15-21: Empty follicle becomes corpus luteum, produces progesterone

  5. Days 21-28: If egg not fertilized, corpus luteum breaks down, progesterone and oestrogen levels drop, endometrium breaks down and is shed (menstruation)
• Male reproductive system


  • Produces sperm, allows fertilization
• Female reproductive system


  • Produces eggs, allows fertilization and development of a new human being
• Reproductive hormones


  • Follicle stimulating hormone (FSH)
  • Luteinising hormone (LH)
  • Oestrogen
  • Progesterone
• Secondary sexual characteristics


  Features that develop during puberty but are not essential for reproduction (e.g. development of pubic hair, voice deepening, breast enlargement)
• Follicle stimulating hormone (FSH)


  Stimulates release of FSH, causes development of Graafian follicles, stimulates cells in follicle to release oestrogen
• Oestrogen


  Stimulates rebuilding of endometrium, inhibits production of FSH, peaks before ovulation causing release of LH
• Luteinising hormone (LH)


  Causes ovulation, causes empty follicle to become corpus luteum which secretes progesterone and oestrogen
• Progesterone


  Keeps rebuilding endometrium, stops production of FSH and LH, decline causes breakdown of endometrium and menstruation
• Menstruation is a normal, healthy process
• Menstrual disorders


  Any problems that interfere with a normal menstrual cycle, e.g. fibroids, endometriosis
• Most women have no problems with their periods