Physiology of the female reproductive system

1. Physiology of the
Female Reproductive
System

2. Physiological Stages
•Neonatal period: birth---4 weeks
•Childhood: 4 weeks----12 years
•Puberty: 12 years---18 years
•Sexual maturation: 18 year---50 year
•Perimenopause: decline of ovarian
function (40 years)----1 year
postmenopause
•Postmenopause:
www.freelivedoctor.com

3. Menstruation
•Menstruation
cyclic endometrium sheds and bleeds due to
cyclic ovulation
•Mense
4.Endometrium is sloughed (progesterone
withdrawal)
5.Nonclotting menstrual blood mainly comes
from artery (75%)
6.Interval: 24-35 days (28 days). duration: 2-6
days. the first day of menstrual bleeding is
consideredy by day 1
7.Shedding: 30-50 ml
www.freelivedoctor.com

4. Central reproductive hormones
•Hypothalamus-Pituitary-Ovary(H-P-O axis)
www.freelivedoctor.com

5. Central reproductive hormones
•Neuroendocrine regulation
2.Gonadotropin-releasing hormone,GnRH
3)chemical structure
(pro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH
2
5)Synthesize and transport



nerve cells
hypothalamus
portal vein
pitutary
anterior lobe
www.freelivedoctor.com

6. Central reproductive hormones
www.freelivedoctor.com

7. Central reproductive hormones
1)Regulation of GnRH
Hypothalams
GnRH
Pituitary
FSH, LH
Ovary
E,P
www.freelivedoctor.com

8. Central reproductive hormones
1.Gonadotropins
2)Composition (glycoprotein)
Follicle stimulating hormone,FSH
Luteinizing hormone,LH
5)Synthesize and transport
Gonadotroph
(pulse)
Blood
circulation
ovary
www.freelivedoctor.com

9. Central reproductive hormones
1.Prolactin (PRL)
Regulated by the prolactin inhibiting factor (PIF)
www.freelivedoctor.com

10. The Ovarian cycle
•Function of ovary
2.Reproduction
development and maturation of follicle;
ovulation
4.Endocrine
estrogens, progesterone, testosterone
www.freelivedoctor.com

11. The Ovarian cycle
•Cyclic changes of ovary
2.The development and maturation of follicle
•Primordial follicle: before meiosis
•Preantral follicle: zona pellucida, granulosa cells
(FSH receptor)
•Antral follicle: granulosa cells (LH receptor), E↑
•Mature follicle: E ,P
↑ ↑
Theca externa, theca interna, granulosa, follicular
antrum, mound, radiate coronal
8)Follicular phase: day 1 to follicle mature (14
days)
www.freelivedoctor.com

12. The Ovarian cycle
www.freelivedoctor.com

13. The Ovarian cycle
1.Ovulation
•First meiosis completed → collagen
decomposed → oocyte ovulated
•Regulation
d)LH/FSH peak
E
2
↑(mature follicle) → GnRH ↑ (hypothalamus)
→ LH/FSH peak (positive feedback)
f)P cooperation
LH P (follicle luteinized before ovulation)
↑→ ↑
positive feedback
→
www.freelivedoctor.com

14. The Ovarian cycle
1.Corpus luteum
•follicle luteinized after ovulation: luteal cells
•LH → VEGF → corpus hemorrhagicum
•Regression
non fertilized corpus albicans
→
6)Luteal phase
Ovulation to day 1
www.freelivedoctor.com

15. The Ovarian cycle
•sex hormones secreted by ovary
2.Composition
Estrogen, progesterone, testosterone
4.Chemical structure
Steroid hormone
6.Synthesis
Cholesterol pregnenolone androstenedione
→ → →
testosterone estradiol
→
Δ
5
or Δ
4
pathway of estrogen production
www.freelivedoctor.com

16. The Ovarian cycle
1.Metabolism: liver
2.Cyclic change of E and P in ovary
3)Estrogen
d)E (day 7) E peak (pre-ovulate) E E
↑ → → ↓→ ↑
(1 day after ovulate) E peak (day 7-8) E
→ → ↓
e)theca interna cells (LH receptor)
→
testosterone
f)Granulosa (FSH receptor) estrogen
→
www.freelivedoctor.com

17. The Ovarian cycle
1)Progesterone
P↑ (after ovulation) → P peak (day 7-8) → P↓
granulosa
progesterone
LH
www.freelivedoctor.com

18. Ovarian responses
www.freelivedoctor.com

19. The Ovarian cycle
•H-P-O axis
2.Positive feedback
Sex hormones (E)↑ GnRH or LH/FSH
→
↑
E peak (≥200pg/ml) LH/FSH peak ovulation
→ →
5.Negative feedback
Sex hormones (E)↑ GnRH or LH/FSH
→
↓
Follicular phase: E
↑
FSH
→
↓
Luteal phase: E↑P
↑
LH/FSH
→
↓(formation)
E↓P↓ LH/FSH
→
↑(regression)
www.freelivedoctor.com

20. The endometral cycle
•Proliferative phase
•E↑(mitogen)→ stroma thickens and glands
become elongated → proliferative
endometrium
•Duration: 2 weeks
•Thickness: 0.5mm → 5mm
www.freelivedoctor.com

21. The endometral cycle
•Secretory phase
•P↑(differentiation) → secretory endometrium
3.Features
stroma becomes loose and edematous
blood vessels entering the endometrium become
thickened and twisted
glands become tortuous and contain secretory
material within the lumina
7.Duration: 2 weeks
8.Thickness: 5-6mm
www.freelivedoctor.com

22. Change of Other genital organs
•Cervix
endocervical glands (E↑) mucus(thin,clear,
→
watery) maximal (ovulation)
→
endocervical glands (P↑) mucus(thick, opaque,
→
tenacious)
•Vagina
Vaginal mucosa (E↑) thickening and secretory
→
changes
Vaginal mucosa (P↑) secrete
→
↓
www.freelivedoctor.com