The Menstrual Cycle

• Menstrual cycle

  1. Menstruation

  2. Uterus lining building up

  3. Ovulation

  4. Uterus lining maintenance
• Menstruation


  The period of bleeding that normally lasts about 4 days and is due to the breakdown of the uterus lining
• Uterus lining building up

  The uterus lining becomes a thick spongy layer with lots of blood vessels, preparing for a fertilized egg
• Ovulation

  The release of an egg from one of the ovaries
• Estrogen


  Produced in the ovaries, stimulates the uterus lining to grow
• Progesterone

  Produced in the ovaries, maintains the uterus lining
• Luteinizing hormone (LH)


  Produced in the pituitary gland, stimulates the release of the egg (ovulation)
• Follicle stimulating hormone (FSH)


  Produced in the pituitary gland, stimulates the maturation of an egg in the ovaries
• Increasing estrogen levels

  Start to inhibit FSH (negative feedback)