Menstrual and Puberty

Puberty and Menstrual Cycle 

  • Puberty: period in which adolescents start to develop secondary sexual characteristics- triggered by reproductive organs

    • Facial hair (men)- testosterone hormone: in testes 

    • Women (breasts)- oestrogen hormone, progesterone hormone : in ovaries 

  • Menstrual cycle 

    • Eggs kept inside the ovaries, after ovulation they are transported along one of the fallopian tubes over to the uterus 

      • If the egg was fertilized it would implant into the uterus lining IF NOT it would break down and pass out 

    • Average menstrual cycle is 28 days 

    • the red: represents the thickness of the uterus wall 

    • Process if you are not pregnant:

    • Process if you are pregnant:

    • Oestrogen hormone: stimulates the uterus lining to grow 

    • Progesterone: increases in stage 4 and maintains the lining of the uterus; if it DROPS→uterus lining would shed (break down) prematurely

    • Follicle stimulating hormone (FSH): pituitary gland- stimulate one of the eggs to mature in one of the ovaries 

    • Luteinising hormone (LH): pituitary gland- stimulates the release of that egg on day 14: ovulation 

    • As the oestrogen levels increase, they inhibit the FSH, which is a negative feedback loop. When oestrogen levels get high, they stimulate the release of LH, which causes the LH spike and results in ovulation. Progesterone inhibits both LH and FSH

    • What happens when there are high levels of estrogen?

      • FSH decreases

    • Average period lasts 2-7 days 

    • What are found inside ovaries?

      • millions of follicles that each contain an oocyte

    • At the end of a typical cycle,  2 things can happen.  What are the 2 possible outcomes?

      • 1) pregnancy 2) period

    • Which gland starts off the cycle?

      • pituitary gland

    • What do the hormones LH and FSH signal?

      • the egg cells to mature

    • Increased levels of estrogen inhibit FSH. What does inhibit in this sense mean?

      • stop the release of

    • Ovulation occurs _______ days before the start of the next period.

      • 10-16 days

    • An egg has  ______ to be fertilized by a sperm cell

      • around 24 hours

    • What hormone is responsible for thickening the uterine lining?

      • Progesterone

    • Summarize what happens when an egg cell is not fertilized each month

      • The lining of the uterus sheds off forming the period

    • It's normal for a woman's period to change length, time and duration throughout their lives.