Physiology of the female
reproductive system
1,Different periods of Female
? Neonatal period, ? 4 weeks
? childhood,4 weeks to age of 12
? adolescence,menarche,age of 12-17
? sexual maturity,begain 18,maintains for 30
years
? peri-menopausal period:begain 40,maintains
for 10-20 years
pre-menopause,menopause(last time of menorrhae),
post-menopause
? senility
2.The definition of
menstruation
?Menarche,the onset of the first menses
occurs about two years after the onset of
pubert
occurs between 13 and 15 years of age
anovulatory for first two years
?The first day of menstrual bleeding is
considered day 1 of the menstrual cycle
?The length of menstrual cycle is 28 –30
days
?The duration of flow is 2-7 days
?The volume of menstrual blood loss is
30ml-50mL(<80mL),darkness and
nonclotting,
The Founction of ovary
? Produce oocyte
? Endocrine,produce female
hormone
3.Reproductive cycle
Devided into 3 phases
?Menstruation,1-4days
?the follicular phase:5-14 days
a number of follicles developing,
only one dominant follicle
others become atretic
ovulation:14th,releasing oocyte
?luteal phase,15-28 days unless pregnancy
occurs
1) Development of ovary
Ovarian cycle is divided into four phases
? Development of follicles
primitive follicles?primary follicles ?
secondary follicles ? antrun/ developing
follicles ? maturity follicles
? ovulation
? corpus luteum
? corpus albican
2)Ovarian steroid hormones
?Estrogens
?rise in plasma by 4th day of cycle
?from granulosa cells and theca cells
?negative feedback to FSH
?positve feedback to LH
?Progesterone,
? from corpus luteum
? maximal production occurs 3-4 days after
ovulation and maintained for 11 days
? negative feedback on FSH and LH
4.Clinical manifestations of
hormone changes
1)Endometrium
be sloughed to a basal level in menstruation
? proliferative phase,5-14 days
(stroma thickens,gland elongated) in follicular
phase,a maximal thickness in ovulation
? Secretory phase,15-28 days
(stroma loose,edematous,
vesseltwisted,gland tortous) in corpus luteum
?Menstrual phase:1-4 days
Endomitrium is sloughed and bleeding onset
2)endocervix
Cervical also changes in response
to the reproductive cycle
Cervical gland secrete
thin,clear,watery,mucus in follicular phase
maximal in ovulation
Mucus becomes thick,opaque,tenacious in
corpus luteum phase
3)vagina
?Thickening and maturation of the surface
epithelial cells responed to E2 in
follicular phase
?thickening and secretory changes of
vaginal epithelium in corpus luteum
phase
4)Hypothalamic
thermoregulating center
?Progesterone shifts the Basal body
temperature upward(BBT)
?BBT record is a useful tool to evaluate
the reproductive cycle
5.H-P-O axis
The control of menstruation is based
on a feedback loop of H-P-O axis
Hypothalamus
? Producing GnRH(gonadotropin-releasing
hormone)
? be secreted in a pulsatile manner
? be a pulse generator of cycle
? be influenced by E and neurotransmitters
Pituitary
?Producing Gonadotropins
follicle-stimulating hormone(FSH)
luteinizing hormone(LH)
?be protein hormones secreted by the
anterior pituitary gland
?be pulsatile manner
?be influenced by E,P,and other factors
Ovaries
ovarian sex steroid hormones
estradiol (E),progesterone(P)
Feedback of H-P-O axis
Concept of feedback
the magnitude and the rate of GnRH,
FSH,LH are determined by E,P,
?negative feedback, resulting in
decreased secretion ofGnRH FSH,LH
? positive feedback,resulting in increased
secretion of LH,which triggers ovulation
Key words
? reproductive cycle
? menstruation
? ovarian cycle
? H-P-O axis
? feedback