2. Think about…
4.1 Hormonal control of the menstrual cycle
4.2 Use of hormones
Recall ‘Think about…’
Summary concept map

3. Prevention of menstruation
during sports games
The performance of female athletes may be affected by their physiological conditions before or during menstruation.

4. Prevention of menstruation
during sports games
Some athletes may take drugs to prevent menstruation from occurring during sports games.

5. Prevention of menstruation
during sports games
The drugs contain hormones which are similar to those naturally produced in the female body.
What are the hormones involved?
How do the drugs prevent menstruation?
Can menstruation be resumed later?

6. Let’s revise the menstrual cycle first.
4.1 Hormonal control of the menstrual cycle
Let’s revise the menstrual cycle first.

7. Cycle repeats until meno…
The menstrual cycle
Cycle repeats until meno…

8. The maturation and release of egg cells from the ovary are synchronized with changes in the uterus

9. Three phases: follicular --- ovulation --- luteal
The Ovarian Cycle
In the ovarian cycle
Hormones stimulate follicle growth, which results in ovulation
Following ovulation
The follicular tissue left behind transforms into the corpus luteum
Three phases: follicular --- ovulation --- luteal
(1-14) (14) (14-28)

10. The Uterine Cycle
Three phases : Menstrual -- proliferative secretory
(1-6) (6-14) (14-28)

11. Day 1 to 5 of the menstrual cycle
4.1
Hormonal control of the menstrual cycle
Day 1 to 5 of the menstrual cycle
uterine lining breaks down
follicle begins to develop

12. Day 5 to 14 of the menstrual cycle
4.1
Hormonal control of the menstrual cycle
Day 5 to 14 of the menstrual cycle
uterine lining begins to thicken
follicle becomes mature

13. Day 14 of the menstrual cycle
4.1
Hormonal control of the menstrual cycle
Day 14 of the menstrual cycle
uterine lining becomes very thick
ovulation occurs

14. Day 14 to 28 of the menstrual cycle
4.1
Hormonal control of the menstrual cycle
Day 14 to 28 of the menstrual cycle
uterine lining remains thick
ovum is moved along the oviduct

15. What are the hormones involved?
4.1
Hormonal control of the menstrual cycle
What are the hormones involved?

16. events synchronized by the interaction of four hormones:
4.1
Hormonal control of the menstrual cycle
events synchronized by the interaction of four hormones:
pituitary gland
follicle stimulating hormone (FSH)
luteinising hormone (LH)

17. events synchronized by the interaction of four hormones:
4.1
Hormonal control of the menstrual cycle
events synchronized by the interaction of four hormones:
yellow body
follicle
oestrogen

18. events synchronized by the interaction of four hormones:
4.1
Hormonal control of the menstrual cycle
events synchronized by the interaction of four hormones:
yellow body
progesterone

19. How do the hormones interact?
4.1
Hormonal control of the menstrual cycle
How do the hormones interact?
the hormones interact by feedback mechanisms

20.  FSH ovary pituitary gland stimulation 4.1
Hormonal control of the menstrual cycle
ovary
pituitary gland
stimulation
 FSH

21.  follicle develops ovary pituitary gland 4.1
Hormonal control of the menstrual cycle
ovary
pituitary gland
 follicle develops

22.  Above a certain level, oestrogen stimulates FSH and LH secretion
4.1
Hormonal control of the menstrual cycle
ovary
pituitary gland
 Above a certain level, oestrogen stimulates FSH and LH secretion

23.  LH ovary pituitary gland
4.1
Hormonal control of the menstrual cycle
ovary
pituitary gland
 LH
LH stimulates oestrogen secretion and oestrogen stimulates FSH and LH secretion ….
A positive feedback effect at around day 14 that raise LH to a peak level

24.  ovulation ovary pituitary gland 4.1
Hormonal control of the menstrual cycle
ovary
pituitary gland
 ovulation

25. 4.1
Hormonal control of the menstrual cycle
ovary
pituitary gland
yellow body
 LH stimulates development of yellow body and hence progesterone secretion

26.  oestrogen and progesterone together inhibit LH and FSH
4.1
Hormonal control of the menstrual cycle
inhibition
ovary
pituitary gland
 oestrogen and progesterone together inhibit LH and FSH

27. Let’s look at the menstrual cycle from day 5.
4.1
Hormonal control of the menstrual cycle
Let’s look at the menstrual cycle from day 5.

28. 1 The pituitary gland secretes FSH.
4.1
Hormonal control of the menstrual cycle
Before ovulation
1 The pituitary gland secretes FSH.
2 FSH stimulates the development of follicles. As the follicle matures, it secretes more oestrogen.
3 Under the action of oestrogen, the uterine lining begins to thicken.
to chart

29. 5 A high level of LH causes ovulation to occur on day 14.
4.1
Hormonal control of the menstrual cycle
Before ovulation
4 Oestrogen level continues to rise and reaches a peak just before ovulation. A high level of oestrogen stimulates FSH and LH secretion. The peaks of FSH and LH occur just after the oestrogen peak.
5 A high level of LH causes ovulation to occur on day 14.
to chart

30. 4.1
Hormonal control of the menstrual cycle
After ovulation
6 The remaining follicle cells form the yellow body. A high level of LH stimulates the yellow body to secrete oestrogen and progesterone. Oestrogen level rises again and progesterone level reaches a peak.
7 Under the action of oestrogen and progesterone, the uterine lining remains thick.
to chart

31. 4.1
Hormonal control of the menstrual cycle
After ovulation
8 High levels of oestrogen and progesterone together inhibit FSH and LH secretion. A low level of LH causes the yellow body to degenerate around day 24.
to chart

32. 4.1
Hormonal control of the menstrual cycle
After ovulation
9 The yellow body gradually stops secreting oestrogen and progesterone and the thickened uterine lining soon breaks down. Also, the inhibition of oestrogen and progesterone on FSH secretion is removed. The pituitary gland secretes more FSH again and the cycle repeats.
to chart

33. levels of pituitary hormones in blood
4.1
Hormonal control of the menstrual cycle
levels of pituitary hormones in blood
events in ovary
levels of ovarian hormones in blood
thickness of uterine lining
to text

34. *Gonadotropin-releasing hormone
Cyclic secretion of GnRH* from the hypothalamus
And of FSH and LH from the anterior pituitary orchestrates the female reproductive cycle
Five hormones involved in an elaborate scheme involving both positive and negative feedback
*Gonadotropin-releasing hormone

35. Hormone Site of Secretion Target Organ Function
Follicle Stimulating Hormone (FSH)
Pituitary gland
Ovary
stimulates the growth & development of the follicle
stimulates secretion of oestrogen
effect of LH in stimulating ovulation
Oestrogen
Endometrium
(lining of the uterus)
stimulates repair of uterine lining
at high conc. inhibits FSH, however during 'pituitary hormone surge' it stimulates further FSH production
as conc. peaks stimulates release of LH
Lutenising Hormone (LH)
Pituitary
stimulates the final development of the follicle
stimulates ovulation
stimulates the development of the corpus luteum
stimulates production of progesterone
Progestrone
Corpus luteum
Uterus
maintains uterine lining endometrium)
inhibits release of FSH
inhibits release of LH
fall in conc. results in menstruation
fall in conc. removes inhibition of FSH and a new cycle begins.

36. Feedback control of human menstrual cycle
Atresia of corpus luteum -- degeneration and resorption of corpus luteum in ovary
Estradiol -- Oestrogen

37. Hormonal feedback control of menstrual cycle

38. The reproductive cycle of the human female

39. The reproductive cycle of the human female

40. human chorionic gonadotrophin (HCG)
4.1
Hormonal control of the menstrual cycle
If fertilization occurs …
placenta
secretes
human chorionic gonadotrophin (HCG)
acts like LH
prevents degeneration of yellow body
 secretes oestrogen and progesterone
 uterine lining remains thick for embryo development

41. What is the significance of hormonal control of the menstrual cycle?
4.1
Hormonal control of the menstrual cycle
What is the significance of hormonal control of the menstrual cycle?

42. Higher survival chance!
4.1
Hormonal control of the menstrual cycle
i) Ensure one ovum is released at a time
after ovulation, high levels of oestrogen and progesterone together inhibit FSH and LH secretion
 prevents maturation of another follicle
Higher survival chance!

43. Avoid wasting of energy!
4.1
Hormonal control of the menstrual cycle
i) Ensure one ovum is released at a time
after ovulation, high levels of oestrogen and progesterone together inhibit FSH and LH secretion
 prevents maturation of another follicle
Avoid wasting of energy!

44. ii) Prepare for implantation
4.1
Hormonal control of the menstrual cycle
ii) Prepare for implantation
oestrogen and progesterone stimulate the thickening of the uterine lining

45. iii) Prepare for the next possible pregnancy
4.1
Hormonal control of the menstrual cycle
iii) Prepare for the next possible pregnancy
if no fertilization occurs, levels of oestrogen and progesterone fall which causes menstruation to occur and the pituitary gland secretes more FSH again
the menstrual cycle repeats

46. 1 Hormonal control of menstrual cycle:
4.1
Hormonal control of the menstrual cycle
1 Hormonal control of menstrual cycle:

47. 2 Significance of hormonal control of the menstrual cycle:
4.1
Hormonal control of the menstrual cycle
2 Significance of hormonal control of the menstrual cycle:
a After ovulation, levels of oestrogen and progesterone together inhibit FSH and LH secretion.
high

48. 2 Significance of hormonal control of the menstrual cycle:
4.1
Hormonal control of the menstrual cycle
2 Significance of hormonal control of the menstrual cycle:
a This prevents the maturation of another follicle and ensures only one ovum is released in each cycle. This would result in higher survival chance of the foetus.

49. 2 Significance of hormonal control of the menstrual cycle:
4.1
Hormonal control of the menstrual cycle
2 Significance of hormonal control of the menstrual cycle:
b Oestrogen and progesterone stimulate the thickening of the uterine lining to prepare for the
implantation
of the embryo.

50. 2 Significance of hormonal control of the menstrual cycle:
4.1
Hormonal control of the menstrual cycle
2 Significance of hormonal control of the menstrual cycle:
c If no fertilization occurs, levels of oestrogen and progesterone fall which causes to occur. The pituitary gland begins to secrete more again.
menstruation
FSH

51. 2 Significance of hormonal control of the menstrual cycle:
4.1
Hormonal control of the menstrual cycle
2 Significance of hormonal control of the menstrual cycle:
c The menstrual cycle repeats to prepare for the next possible pregnancy.

52. used as contraceptives or in the treatments of infertility
4.2 Use of hormones
used as contraceptives or in the treatments of infertility

53. How are hormones used to prevent pregnancy?
4.2
Use of hormones
How are hormones used to prevent pregnancy?
contraceptive pills contain synthetic progesterone or a combination of synthetic oestrogen and progesterone
 high levels inhibit FSH and LH secretion
 follicle development and ovulation do not occur

54. contraceptive pills for 21 days for 28 days hormone-free 4.2
Use of hormones
contraceptive pills
for 21 days
for 28 days
hormone-free

55. contraceptive patches and injections
4.2
Use of hormones
contraceptive patches and injections
to be replaced weekly
to be taken every 3 months

56. How the injection works (ref)
The contraceptive injection works in the same way as the implant. It steadily releases the synthetic hormone progestogen into your bloodstream.
The continuous release of progestogen:
stops a woman releasing an egg every month (ovulation) 
thickens the mucus from the cervix (neck of the womb), making it difficult for sperm to pass through to the womb and reach an unfertilised egg 
makes the lining of the womb thinner so that it is unable to support a fertilised egg
Disrupted periods
Periods irregular and may be very heavy, or shorter and lighter, or stop altogether. This may settle down after the first year, but may continue as long as the injected progestogen remains in your body.
It can take a while for your periods and natural fertility to return after you stop using the injection. It takes around eight to 12 weeks for injected progestogen to leave the body, but you may have to wait longer for your periods to return to normal if you are trying to get pregnant.

57.  prevent ovulation and implantation
4.2
Use of hormones
morning-after pills contain a high dose of synthetic progesterone or a combination of synthetic oestrogen and progesterone
 prevent ovulation and implantation
 prevent pregnancy after sexual intercourse

58. They are not for regular use and must be prescribed by doctors.
4.2
Use of hormones
They are not for regular use and must be prescribed by doctors.

59. How are hormones used to treat infertility?
4.2
Use of hormones
How are hormones used to treat infertility?
causes of infertility:
does not produce enough sperm
sperm have low motility
sperm have structural defects

60. How are hormones used to treat infertility?
4.2
Use of hormones
How are hormones used to treat infertility?
causes of infertility:
fails to release ova from the ovaries
oviducts are blocked
uterine environment does not allow implantation

61. fertility drugs contain: - FSH  stimulates follicle development
4.2
Use of hormones
fertility drugs contain:
- FSH
 stimulates follicle development

62. fertility drugs contain: - LH  stimulates ovulation
4.2
Use of hormones
fertility drugs contain:
- LH
 stimulates ovulation

63. fertility drugs contain: - synthetic oestrogen and progesterone
4.2
Use of hormones
fertility drugs contain:
- synthetic oestrogen and progesterone
 stimulates the thickening of the uterine lining to prepare for implantation of the embryo

64. 1 Synthetic and oestrogen progesterone are present in
4.2
Use of hormones
1 Synthetic and
oestrogen
progesterone
are present in
contraceptives. They inhibit and secretion by the pituitary
FSH LH
gland. This prevents follicle development and ovulation, so that no ova are released into the oviducts for fertilization.

65. 4.2
Use of hormones
2a FSH, LH, , synthetic oestrogen and progesterone are present in fertility drugs.
HCG

66. 4.2
Use of hormones
2b FSH promotes development. LH and HCG stimulate Synthetic oestrogen and progesterone stimulate the thickening of the uterine lining to prepare for
follicle
ovulation
implantation .

67. 1 What are the hormones present in the drugs?
The drugs contain synthetic oestrogen and progesterone.

68. 2 How do the drugs prevent menstruation?
High levels of oestrogen and progesterone in blood maintain the thickness of the uterine lining to prevent menstruation.

69. 3 How can menstruation be resumed?
Menstruation will resume after the female has stopped taking the drugs.

70. treatment of fertility
Menstrual cycle
is controlled by interaction of
pituitary hormones
ovarian hormones
can be used as
contraceptives
treatment of fertility

71. follicle stimulating hormone (FSH) luteinising hormone (LH)
pituitary hormones
include
follicle stimulating hormone (FSH)
luteinising hormone (LH)
stimulates
stimulates
ovulation
follicle development
yellow body formation

72. ovarian hormones oestrogen progesterone uterine lining menstruation
include
oestrogen
progesterone
stimulate thickening of
low levels cause
uterine lining
menstruation
to prepare for
implantation