Female Reproductive Cycle In-je University Medical College 인체 발생의 시작 : 제 1주 2013. 03. 22 Department of Anatomy In-je University Medical College

Contents Ovarian cycle 2. Menstrual cycle 3. Contraception

Overview Hypothalamus – GnRH – Pituitary – Ovaries - Endometrium Hormonal changes  functional and morphological changes in ovaries  ovulation  endometrial changes  implantation or menstruation Ovarian cycle – series of events in ovaries that occur during and after maturation of oocyte Menstrual (Uterine) cycle – concurrent series of changes in uterine endometrium preparing it for arrival of fertilized ovum = Ovarian + Endometrial + Cervical + Vaginal + Breast + Psychological + Others

Ovarian cycle Averages 28 days, ranges from 20 to 45 Hormone cycle: hypothalamus pituitary  ovaries  uterus Follicular phase (1~14day) period of follicle growth menstruation occurs (3~5day) uterus replaces lost endometrium and follicles grow Luteal phase (15~28day) period of corpus luteum activity corpus luteum stimulates endometrial thickening endometrium lost without pregnancy

Ovarian cycle - Follicular phase Menstruation (day 1) to ovulation(14) (variable) Difficult to predict date of ovulation Contains menstrual and preovulatory phases

Follicular development primordial follicle primary follicle secondary(growing) follicle mature(Graafian) follicle Estrogene 분비 The primordial follicle, directed by the oocyte, becomes a primary follicle Primary follicle becomes a secondary follicle The theca folliculi and granulosa cells cooperate to produce estrogens The zona pellucida forms around the oocyte The antrum is formed The secondary follicle becomes a mature Graafian follicle The antrum expands and isolates the oocyte and the corona radiata The full size follicle (vesicular follicle) bulges from the external surface of the ovary The primary oocyte completes meiosis I, and the stage is set for ovulation Follicle rupture and release ovum Ruptured follicle luteinize and produce corpus luteum

Feedback mechanisms in ovarian function Figure 27.21

LH surge 혈중 estrogen 치가 최고치일 때 대개 12, 13일 쯤에 나타남 Lasts for 48 hrs Ovulation occurs after 36 hrs Accompanied by rapid fall in estradiol level Triggers the resumption of meiosis Affects follicular wall  follicular rupture Granulosa cells  lutenization  progestrone synthesis

Ovulation ; 14 ± 1 day Ovulation occurs when the ovary wall ruptures and expels the secondary oocyte midcycle LH surge - dramatic increase prostaglandin, proteolytic enzyme - weaken the follicular wall and then ruptured

Ovulation ◈ Cause ◈ ovulated mass LH surge Graafian follicle → increase of follicular fluid Ruptual of stigma ◈ ovulated mass Meiotic II metaphase oocyte The zona pellucida (; clear zone) forms around the oocyte Graafian follicle= cumulus oophorus → corona radiata

Ovulation signs 관찰방법 Basal body temperature Spotted bleeding mild abdominal cramps, 중간 통증 over-the-counter ovulation kit → LH 증가 : test your urine for the surge in hormones that takes place before ovulation Blood, 혈액검사 → protesterone 증가 자궁경부 점액 관찰법 : clear, slippery vaginal secretions, 분비물 증가 조직 검사시, secretary phase로의 이행, 변화 관찰 질 초음파 검사법

Ovarian cycle - Ovulation Mature follicle ruptures, releases oocyte influenced by LH

Luteal phase After ovulation, the ruptured follicle collapses, granulosa cells enlarge, and along with internal thecal cells, form the corpus luteum The corpus luteum secretes progesterone and estrogen If pregnancy does not occur, the corpus luteum degenerates in 10 days, leaving a scar (corpus albicans) If pregnancy does occur, the corpus luteum produces hormones until the placenta takes over that role (at about 3 months)

Ovarian cycle - Luteal phase Corpus luteum - forms from ruptured follicle, under influence of LH; secretes progesterone

Menstrual cycle Name of phase Days menstrual phase 1–5 follicular phase (also known as proliferative phase) 6–13 ovulation (not a phase, but an event dividing phases) 14 luteal phase (also known as secretory phase) 15–26 ischemic phase (some sources group this with secretory phase) 27–28

Uterine wall Composed of three layers Endometrium Composed of three layers Perimetrium – outermost serous layer; the visceral peritoneum Myometrium – middle layer; consists of interlacing layers of smooth muscles Endometrium – mucosal lining of the uterine cavity. It has numerous uterine glands and consists of Compact layer Sponge layer Basal layer

Endometrium

1. Menstrual phase ; 1~5days Blood, serous fluid and endometrial tissue are discharged Corpus luteum → corpus albicans Functional layer 탈락 ; menstruation → 1~5days, 50~150ml (20~40ml blood, 응고하지 않음)

2. Proliferative phase ; 6~14days, follicular phase Proliferation Phase starts in the anterior pituitary gland with the release of FSH. FSH goes to the ovaries and causes the ovarian graafian follicle (ovum) to develop/mature. Follicle begins to mature (theca cell)- releases ESTROGEN Estrogen causes the uterine lining to thicken in preparation of the ovum (egg) and causes the ovum to ripen and enlarge. → endometrial growth reached maximum When estrogen levels get high enough they cause the release of LH or luteinizing hormone

3. Secretory phase ; 15~26days, luteal phase After ovulation, the ruptured follicle collapses, granulosa cells enlarge, and along with internal thecal cells, form the corpus luteum The corpus luteum secretes progesterone and estrogen If pregnancy does not occur, the corpus luteum degenerates in 10 days, leaving a scar (corpus albicans) If pregnancy does occur, the corpus luteum produces hormones until the placenta takes over that role (at about 3 months)

5. Ischemic phase Involution of corpus luteum, progesterone falls ; 27~28days Involution of corpus luteum, progesterone falls corpus luteum → corpus albicans spiral arteries constrict causes endometrial ischemia stratum functionalis sloughs

Premenstrual Syndrome - PMS PMS often occurs after ovulation. Over 150 symptoms have been reported that have been related to PMS. Treatment includes counseling, medications, dietary changes, regular exercise.

Gonadotropins, Hormones, and the Ovarian and Uterine Cycles

Hormonal interactions in the ovarian and uterine cycles

Contraception Rhythm method Contraceptives a. estrogen + progesterone 적당량 지속적 투여 → combined contraceptives (=COCs) → ovarian cycle이 block됨. b. Emergency contraceptives (=EC) → 아주 많은 양의 progesterone과 estrogen 투여 → morning-after pills c. 임신 중절 → progesterone inhibitor → dilatation & curettage (=D&C)

Various birth control devices