Physiology of the female Physiology of the female reproductive systemreproductive system

1. 1. Different periods of FemaleDifferent 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

2.2.The definition of The definition of menstruationmenstruation

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 daysThe volume of menstrual blood loss is

30ml-50mL(<80mL),darkness and nonclotting.

The Founction of ovaryThe Founction of ovary Produce oocyte Endocrine: produce female

hormone

3.3.Reproductive cycleReproductive cycleDevided into 3 phasesMenstruation: 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) 1) Development of ovaryDevelopment of ovaryOvarian cycle is divided into four phases

Development of follicles primitive folliclesprimary follicles secondary follicles antrun/ developing follicles maturity follicles ovulation corpus luteum corpus albican

2)2)Ovarian steroid hormonesOvarian steroid hormones

Estrogensrise in plasma by 4th day of cycle from granulosa cells and theca cellsnegative feedback to FSHpositve 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

4.4.Clinical manifestations of Clinical manifestations of hormone changeshormone 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)2)endocervixendocervix

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)3)vaginavaginaThickening 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)4)Hypothalamic Hypothalamic thermoregulating centerthermoregulating center

Progesterone shifts the Basal body temperature upward(BBT)

BBT record is a useful tool to evaluate the reproductive cycle

5.5.H-P-O axisH-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

PituitaryProducing Gonadotropins follicle-stimulating hormone(FSH) luteinizing hormone(LH)be protein hormones secreted by the

anterior pituitary glandbe pulsatile mannerbe influenced by E,P, and other factors

Ovaries ovarian sex steroid hormones

estradiol (E), progesterone(P)

Feedback of H-P-O axisFeedback 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 wordsKey words reproductive cycle menstruation ovarian cycle H-P-O axis feedback