Physiology of the
Female Reproductive
System
Liu Wei
Department of Ob & Gy
Ren Ji hospital
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,
Menstruation
? Menstruation
cyclic endometrium sheds and bleeds due to
cyclic ovulation
? Mense
1,Endometrium is sloughed (progesterone
withdrawal)
2,Nonclotting menstrual blood mainly comes
from artery (75%)
3,Interval,24-35 days (28 days),duration,2-6
days,the first day of menstrual bleeding is
consideredy by day 1
4,Shedding,30-50 ml
Central reproductive hormones
? Hypothalamus-Pituitary-Ovary(H-P-O axis)
Central reproductive hormones
? Neuroendocrine regulation
1,Gonadotropin-releasing hormone,GnRH
1) chemical structure
(pro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2
2) Synthesize and transport
nerve cells
hypothalamus
portal vein
pitutary
anterior lobe
Central reproductive hormones
Central reproductive hormones
3) Regulation of GnRH
Hypothalams
GnRH
Pituitary
FSH,LH
Ovary
E,P
Central reproductive hormones
2,Gonadotropins
1) Composition (glycoprotein)
Follicle stimulating hormone,FSH
Luteinizing hormone,LH
2) Synthesize and transport
Gonadotroph
(pulse)
Blood
circulation
ovary
Central reproductive hormones
3,Prolactin (PRL)
Regulated by the prolactin inhibiting factor (PIF)
The Ovarian cycle
? Function of ovary
1,Reproduction
development and maturation of follicle;
ovulation
2,Endocrine
estrogens,progesterone,testosterone
The Ovarian cycle
? Cyclic changes of ovary
1,The development and maturation of follicle
1) Primordial follicle,before meiosis
2) Preantral follicle,zona pellucida,granulosa cells
(FSH receptor)
3) Antral follicle,granulosa cells (LH receptor),E↑
4) Mature follicle,E↑,P↑
Theca externa,theca interna,granulosa,follicular
antrum,mound,radiate coronal
5) Follicular phase,day 1 to follicle mature (14
days)
The Ovarian cycle
The Ovarian cycle
2,Ovulation
1) First meiosis completed → collagen
decomposed → oocyte ovulated
2) Regulation
a) LH/FSH peak
E2↑( mature follicle) → GnRH ↑ (hypothalamus)
→ LH/FSH peak (positive feedback)
b) P cooperation
LH ↑ → P ↑ (follicle luteinized before ovulation)
→ positive feedback
The Ovarian cycle
3,Corpus luteum
1) follicle luteinized after ovulation,luteal cells
2) LH → VEGF → corpus hemorrhagicum
3) Regression
non fertilized → corpus albicans
4) Luteal phase
Ovulation to day 1
The Ovarian cycle
? sex hormones secreted by ovary
1,Composition
Estrogen,progesterone,testosterone
2,Chemical structure
Steroid hormone
3,Synthesis
Cholesterol→ pregnenolone→ androstenedione→
testosterone→ estradiol
Δ5 or Δ4 pathway of estrogen production
The Ovarian cycle
4,Metabolism,liver
5,Cyclic change of E and P in ovary
1) Estrogen
a) E↑ (day 7) → E peak (pre-ovulate) → E↓ →
E↑ (1 day after ovulate) → E peak (day 7-8) →
E↓
b) theca interna cells (LH receptor) →
testosterone
c) Granulosa (FSH receptor) → estrogen
The Ovarian cycle
2) Progesterone
P↑ (after ovulation) → P peak (day 7-8) → P↓
granulosa
progesterone
LH
Ovarian responses
The Ovarian cycle
? H-P-O axis
1,Positive feedback
Sex hormones (E)↑ → GnRH or LH/FSH↑
E peak (≥200pg/ml) → LH/FSH peak → ovulation
2,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)
The endometral cycle
? Proliferative phase
1,E↑ (mitogen)→ stroma thickens and glands
become elongated → proliferative
endometrium
2,Duration,2 weeks
3,Thickness,0.5mm → 5mm
The endometral cycle
? Secretory phase
1,P↑ (differentiation) → secretory endometrium
2,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
3,Duration,2 weeks
4,Thickness,5-6mm
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↓
Physiological function of sex hormones
? Estrogen
END