Menstrual Cycle Mrs Teo CC

Stages of Menstrual Cycle Menstruation Repair and Growth of Uterine Lining Ovulation Further thickening of Uterine Lining

1. Menstruation If no fertilisation occurs after ovulation, ovaries will stop producing hormones ovum disintegrates thick lining of uterus breaks down broken lining, disintegrated egg and some blood flow out through the vagina – menstrual flow - marking the start of menstruation menstruation lasts for about 5 days

2. Repair and Growth of Uterine Lining (after menstruation) after menstruation, ovaries release oestrogen into bloodstream oestrogen causes growth and repair of uterine lining and blood capillaries to form within the thick lining - uterine wall becomes thick and spongy with blood vessels again

3. Ovulation occurs about the 14th day of the menstrual cycle if fertilisation occurs - the female becomes pregnant if no fertilisation occurs - menstruation occurs again 14 days after ovulation for married couples who want to have children, sexual intercourse during period of ovulation is more likely to result in pregnancy

4. Further thickening of Uterine Wall after ovulation, ovary secretes progesterone into bloodstream progesterone causes uterine lining to thicken further and becomes vascularised (contain many blood capillaries) - ready for implantation of embryo if there is no fertilisation, uterine lining breaks down and menstruation starts again

Menstrual Cycle Start Uterine lining grows and thickens Repair and growth of uterine lining Uterine lining thickens further and becomes more vascular, preparing for implantation Uterine lining breaks down and is discharged Start

Thickness of Uterine Lining during Menstrual Cycle

Irregularities in menstrual cycle can be caused by:  stress  emotional disturbances  mental fatigue  illness  unbalanced diet, malnutrition

The Fertile and Infertile phases an ovum released during ovulation can live for 2 - 3 days before it dies sperm released into the female reproductive system can live for 2 - 3 days time from day 11 to 17 - fertile phase because fertilisation can occur during this period rest of the days in the menstrual cycle - infertile phase because fertilisation is usually not possible during this period