female sex cycle

1. Physiology of Female
Reproductive System
Datu Agasi Bin Mohd Kamal

2. Learning Objectives:
• To know the process of oogenesis.
• To describe the follicular development.
• To explain the female sexual cycle.
• To describe sign of ovulation.

3. Case
A 25-year-old woman is investigated for infertility. She has been
married to a 25-year-old man for 2 years and they have been
trying to have a baby since then, without success. She is a thin
(height 155 cm, weight 46 kg), and healthy looking woman.
She attained her menarche at 15 years old. In general, they have
been regular, with a cycle length over the last few years of about
24 days. She does not experience premenstrual pain. She has
been a long distance runner since her early teens and has been
involved regularly in high level competition since the age of 15.
She has noticed that during times of intense pre-competition
training, she sometimes misses her menses altogether.

4. Ova Production
• 7 million
Primordial
follicle
Fetal
Development
• 2 million
Primordial
follicle
Birth
• 300 000
follicle
Puberty
• 400-500
mature and
release ova
Reproductive
Year
• Few follicle
Menopause

5. Oogenesis

6. Puberty
• Puberty occurs between ages of 8-13 years in girls.
• Triggered by rising levels of GnRH which stimulates
anterior lobe of pituitary to produce
• follicle-stimulating hormone (FSH)
• luteinizing hormone (LH)
• FSH stimulates ovarian follicles development and they
begin to secrete estrogen, progesterone.
• This leads to the onset of normal monthly sexual cycle
which is consist of ovarian cycle and menstrual cycle.

7. Female
Sexual
Cycle

8. Ovarian Cycle
GnRH
dependent
Secrete
oestrogen
FSH recruit
15/20 follicle
per cycle
Dominant
follicle- FSH
receptor
Follicular phase
Luteal phase
Secrete
oestrogen&
progesterone
LH regulated

9. Oestrogen production
Contain
aromatase
enzyme

10. Ovarian cycle control
Follicular Phase

11. Ovarian cycle control
Ovulation Phase

12. Ovarian cycle control
Luteal Phase

13. Menstrual Cycle
• Menstrual phase- ovarian
hormone fall stimulate
prostaglandin causes
vasoconstrition-ischemia +
contraction of uterine
myometrium
• Average blood loss 50-150
mL
• Fibrinolysin-prevent clot

14. Menstrual Cycle
Proliferative phase:
• estrogen stimulate growth of myometrium and
endometrium
• Induce synthesis of progesterone receptor in the
endometrium
Secretory phase:
• Progesterone – accumulation of electrolyte and water
to facilitate implantation
• Endometrial gland secrete glycogen to uterime lumen
for embryo nourishment

15. Anovulatory Cycles
• Common 12-18 month after menarche and
before menopause
• No ovulation , no corpus luteum so
progesterone effect on endometrium absent.
• Estrogen continue to grow the endometrium
which eventually break down and slough
• Usually bleeding is less than 28 days

16. Signs of Ovulation
– cervical mucus becomes thinner and more stretchy
– Resting body temperature rises (progesterone effect)
– LH surge occurs about 24 hours prior to ovulation
• detected with home testing kit
– twinges of ovarian pain
• from a few hours to a day or so at the time of ovulation

17. Cervical mucus pattern
• Estrogen effect-thinner,more
alkaline,fern like pattern –
promote sperm transport
&survival.
• Progesterone –
thick,tenacious ,cellular.
• Ovulation – thinnest
mucus,spinnbarkeit
increases,long thin thread 8-
12cm or more.
Fern like
pattern

18. Temperature rise

19. Menarche
• Requires at least 17% body fat in teenager, 22% in adult
• Improved nutrition has lowered age of onset to age 12
• Leptin (satiety-producing hormone secreted by fat cell) stimulates
gonadotropin secretion
• If body fat and leptin levels drop too low for example in women
engage in strenuos athletics, gonadotropin secretion declines and a
female’s menstrual cycle might cease
• Girls begin ovulating regularly about a year after they begin
menstruating

20. Athletic menstrual cycle irregularities
• Varies from amenorrhea,oligo-
menorrhea,normal in length but anovulatory
or cycle with short luteal phase
• Delayed menarche
• Cycle return normal after training stopped
• Mechanism unknown- probably rapid weight
loss, low body fat, stress.

21. Thank You

22. Female Sexual Cycle
• The normal reproductive years of female are characterized by monthly
cyclical variation in secretion of female hormone which cause the
female monthly sexual cycle.
• It consists of two interrelated cycles controlled by shifting patterns of
hormone secretion
• Ovarian cycle - events in ovaries
• Menstrual cycle - parallel changes in uterus
• Sexual cycle recur every month when pregnancy does not intervene
• The cycle average duration is 28 days.
• It varies from 20-45 days in some women.
• Two significant :
i. Release single ovum each cycle
ii. Prepared endometrium for implantation.

23. 28-27
The Sexual Cycle
• cycle begins with 2 week follicular phase
– menstruation occurs during first 3 to 5 days of cycle
– uterus replaces lost tissue, and cohort of follicles grow
– ovulation around day 14 –remainder the of follicle becomes
corpus luteum
• next 2 weeks the luteal phase
– corpus luteum stimulates endometrial (uterine lining) secretion
and thickening
– if pregnancy does not occur, endometrium breaks down in the last
2 days
– menstruation begins and the cycle starts over

24. Ovarian Cycle
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Days 1 3 5 7 9 11 13 15 17 19 21 23 25 27 1
(a) Ovarian cycle
LH
Developing follicles
Primary
Tertiary
Secondary
Ovulation
Luteal phaseFollicular phase
Corpus luteum Involution
OvarianeventsGonadotropinsecretion
FSH
New primordial
follicles
Corpus
albicans

29. Development of egg (oogenesis) Development of follicle (folliculogenesis)
2n
2n
n
n
n
n
n
n
n
2n
Mitosis
Primary oocyte
Secondary oocyte
Meiosis I
If fertilized
If not fertilized
Meiosis II
Zygote
Embryo
Before birth
Adolescence to menopause
Primordial follicle
No change
Granulosa cells
Primary follicle
Tertiary follicle
Secondary follicle
Corpus luteum
Dies
Oocyte
Nucleus
Follicular fluid
Granulosa cells
Zona pellucida
Theca folliculi
Antrum
Multiplication
of oogonia
Follicular
cells
Cumulus
oophorus
Theca
interna
Theca
externa
Secondary oocyte
(ovulated)
Second polar
body (dies)
Ovulation of
mature
(graafian)
follicle
First polar
body (dies)
Bleeding into
antrum
Ovulated
oocyte

32. Female Reproductive System

33. 28-37
Climacteric and Menopause
• climacteric -midlife change in hormone secretion
– accompanied by menopause – cessation of menstruation
• female born with about 2 million eggs, climacteric begins when there
are about 1000 follicles left
– less estrogen and progesterone secretion
– uterus, vagina, and breast atrophy
– vagina becomes thinner, less distensible, and drier
– cholesterol levels rise, increasing the risk of cardiovascular disease
– bone mass declines - increased risk for osteoporosis
– hot flashes – spreading sense of heat from the abdomen to the
thorax, neck, and face
• hormone replacement therapy (HRT) – low doses of estrogen and
progesterone to relieve some of these symptoms

34. 28-38
Puberty
• puberty begins at age 8-10 for most girls in US
• triggered by rising levels of GnRH
– stimulates anterior lobe of pituitary to produce
• follicle-stimulating hormone (FSH)
• luteinizing hormone (LH)
• FSH stimulates developing ovarian follicles and they
begin to secrete estrogen, progesterone, inhibin, and a
small amount of androgen
• estrogens are feminizing hormones with widespread
effects on the body
– estradiol (most abundant), estriol, and estrone

35. Hormones of Puberty
• estradiol
– stimulates vaginal metaplasia
– stimulates growth of ovaries and secondary sex organs
– stimulates growth hormone secretion
– responsible for feminine physique - stimulates the deposition of fat
– makes a girl’s skin thicker
• progesterone
– primarily acts on the uterus preparing it for possible pregnancy in
the second half of the menstrual cycle
• estrogens and progesterone suppress FSH and LH secretion through
negative feedback

36. 28-40
Oogenesis
• oogenesis – egg production
– produces haploid gametes by means of meiosis
– distinctly cyclic event that normally releases one egg each month
– accompanied by cyclic changes in hormone secretion
– cyclic changes in histological structure of the ovaries and uterus
• a girl is born with all of the eggs she will ever produce
– primary oocytes
– egg, or ovum – any stage from the primary oocyte to the time of
fertilization
– by puberty 400,000 oocytes remain
• a lifetime supply – probably will ovulate around 480 times

37. 28-41
Oogenesis
• egg development resumes in adolescence
– FSH stimulates monthly cohorts of oocytes to complete meiosis I
– each oocyte divides into two haploid daughter cells of unequal
size and different destinies
• secondary oocyte – large daughter cell from meiosis I
• first polar body – smaller one that ultimately disintegrates
• secondary oocyte proceeds as far as metaphase II
– arrests until after ovulation
– if not fertilized, it dies and never finishes meiosis
– if fertilized, it completes meiosis II and casts off a second
polar body
– chromosomes of the large remaining egg unite with those of the
sperm

38. 28-42
Figure 28.11
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(Primordial & Primary follicle): © Ed Reschke;(Secondary follicle): © The McGraw-Hill Companies, Inc./Photo by Dr. Alvin Telser; (Tertiary follicle): Manfred Kage/Peter
Arnold, Inc.; (Graafian): Landrum Dr. Shettles; (Corpus luteum): © The McGraw-Hill Companies, Inc./Photo by Dr. Alvin Telser
Development of egg (oogenesis) Development of follicle (folliculogenesis)
2n
2n
n
n
n
n
n
n
n
2n
Mitosis
Primary oocyte
Secondary oocyte
Meiosis I
If fertilized
If not fertilized
Meiosis II
Zygote
Embryo
Before birth
Adolescence to menopause
Primordial follicle
No change
Granulosa cells
Primary follicle
Tertiary follicle
Secondary follicle
Corpus luteum
Dies
Oocyte
Nucleus
Follicular fluid
Granulosa cells
Zona pellucida
Theca folliculi
Antrum
Multiplication
of oogonia
Follicular
cells
Cumulus
oophorus
Theca
interna
Theca
externa
Secondary oocyte
(ovulated)
Second polar
body (dies)
Ovulation of
mature
(graafian)
follicle
First polar
body (dies)
Bleeding into
antrum
Ovulated
oocyte
Oogenesis and
Follicle
Development

39. 28-43
Histology of Ovarian Follicles
Figure 28.12b
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Manfred Kage/Peter Arnold, Inc
Granulosa cells
Oocyte nucleus
Oocyte (egg)
Zona pellucida
Cumulus oophorus
Antrum
Theca folliculi
(b) 100 µm