Ovulation - GU PDF

OVULATION FUNCTIONS OF OVARY PRODUCE OVA PRODUCE HORMONES OESTROGENS PROGESTERONE ANDROGENS  DEVELOPMENT OF OVARY  GONADAL RIDGE ESTABLISHED AT 5 WEEKS  CHROMOSOMAL SEX IDENTIFIED  NOT DIFFERENTIATED INTO OVARY OR TESTES  GONADAL RIDGE FORMED -THE PRIMITIVE GER...

OVULATION FUNCTIONS OF OVARY PRODUCE OVA PRODUCE HORMONES OESTROGENS PROGESTERONE ANDROGENS  DEVELOPMENT OF OVARY  GONADAL RIDGE ESTABLISHED AT 5 WEEKS  CHROMOSOMAL SEX IDENTIFIED  NOT DIFFERENTIATED INTO OVARY OR TESTES  GONADAL RIDGE FORMED -THE PRIMITIVE GERMINAL CELLS DEVELOP IN THE ENDODERMAL CELLS OF YOLK SAC. MIGRATE ALONG THE DORSAL MESENTRY OF THE HIND GUT TO THE GONADAL RIDGE (THE ONLY SITE WHERE IT CAN LIVE)  DIRECTPRECURSOR OF OVA AND SPERMS MULTIPLY BY MITOTIC DIVISION  COELOMIC EPITHELIUM  MEDULLARY MESENCHYME TISSUE  THE GONADAL RIDGE DEVELOP IN EITHER TESTES (46XY) OR (46XX). BY 7 WEEK TESTES: SEX CORDS GIVE RETE TESTIS, SEMINIFEROUS TUBULES AND STRAIGHT TUBULES FAILURE OF TESTICULAR FEATURES TO APPEAR MEANS THAT THE GONAD IS AN OVARY- MAINLY CORTEX  FOLLICLE FORMATION  PRIMITIVE GERM CELLS CHANGE INTO OOCYTES  OOCYTES ARE INVESTED WITH A LAYER OF MESENCHYMAL CELLS WHICH BECOME GRANULOSA CELLS TO FROM THE PRIMORDIAL FOLLICLE  OOCYTES WHICH FAIL TO BE SURROUNDED BY GRANULOSE CELLS DISINTEGRADE PRIMORDIAL FOLLICLE - AN OOCYTE IN THE FIRST MEIOTIC DIVISION ARRESTED AT THE DIPLOTENE STAGE OF PROPHASE - SURROUNDED BY TWO LAYERS OF GRANULOSA CELLS.  THE REMAINING OF MESENCHYMAL CELLS FORMS THE STROMA  GERMCELLS = 7,000,000 AT 5 MONTHS EMBRYO = 2,000,000 AT BIRTH = 300,000-500,000 AT PUBERTY  LOSS OF OOCYTS BY ATRESIA.  FOLLICLE FORMATION BOTH OVARIES FUNCTION AS ONE UNIT. ONE OVUM EACH CYCLE ALTERNATING  INITIAL RECRUITMENT DOES NOT DEPEND ON FSH.  MATURATION DEPEND ON FSH  RECRUITMENT CONTINOUS TILL MENOPAUSE RATE DEPEND ON STORAGE DECREASE RAPIDY AFTER 38 YEARS  ONE DOMINANT FOLLICLE PROCEED TO PER-OVULATORY  FOLLICLE AND REST UNDERGO ATRESIA  GRANULOSA CELLS DEVELOP FSH RECEPTORS. FSH STIMULATES MATURATION OF FOLLICLE  ZONA PELLUCIDA FORM AROUND OOCYTE  INCREASE IN SIZE AND NUCLEUS OF OOCYTE  PROLIFERATION OF GRANULOSE CELLS TO MANY LAYES  SECRETE LIQUOR FOLLICULLII- ANTRAL FLOLLICLE GRANULOSA CELLS AROUND THE OOCYLE= CUMULUS OOPHORUS  SURROUNDING STROMA, THECA CELLS  MATURE PRE-OVULATORY FOLLICLE  OVULATION  OVULATION IS THE PROCESS BY WHICH AN OVUM IN THE FORM OF SECONDARY OOCYTE COMES OUT OF THE OVARIAN FOLLICLE AND LEAVE THE OVARY.  THE LH SURGE TRIGGERS OVULATION THE LH SURGE STIMULATED BY OESTROGEN PEAK- POSITIVE FEEDBACK  OVULATION OCCURS 38 HOURS AFTER LH SURGE   AND 60 HOURS AFTER OESTROGEN PEAK THERE FORE THE FOLLICLE DETERMINES ITS OVULATION  LH SURGE 1. RESUME FIRST MEIOTIC DIVISION 2. LEUTINIZATION OF GRANULOSE CELLS 3. PGE2 PGF 2α SCRETED BY GRANULOSA CELLS. INCREASE VASCULARITY AND HYDROLASES FROM  EPITHELIAL CELLS OF THE FOLLICLE WALL 4. PLASMINOGEN ACTIVATOR CONVERT PLASMINOGEN TO PLASMIN WHICH DEGRADES FIBRIN  PLASMIN ACTIVATES METALLOPROTINASES WHICH DIGEST THE FOLLICLE WALL  THE INTRAFOLLICULAR PRESSURE DOES NOT RISE, THE FOLLICLE WALL WEAKNES AND  LEAKS AND RUPTURE AND THE OOCYTE SURROUNDED BY THE CUMULUS OOZES OUT  THE OOCYTE ENTER THE TUBE. IF NOT FERTILIZED DIED AFTER 12 HOURS  MATURATION OF OVUM- OOCYTE  LL PRIMARY OOCYTES ARRESTED IN THE FIRST MEIOTIC DIVISION- PROPRPHASE  LH SURGE- RESUME MEIOTIC DIVISION  DIVISION COMPLETED 36 HOURS BEFORE OVULATION  FIRST MEIOTIC DIVISION RESULT IN SECONDARY OOCYTE 23 CHROOMOSOMES FIRST POLAR BODY  SECOND MEIOTIC DIVISION STARTS AFTER FERTILIZATION  CORPUS LUTEUM:  THE FOLLICLE CHANGES TO CORPUS LUTEUM AFTER OVULATION  LUTEINIZATION IS INTRACELLULAR ACCUMULATION OF CHOLESTEROL INCREASED CYTOCHROME P 450   WHICH COVERT CHOLESTEROL TO PROGESTROME AND INHBITS CONVERSION OF PROGESTERONE TO ANDROSTEINDION VASCULARIZATION OF GRANULOSA CELLS. FORMED OF GRAANULOSA CELL AND THECA CELLS.  AROMATASE ACTIVITY, GRANULOSA CELLS PRODUCE OESTRADIOL FROM ANDROGENS  PRODUCED BY THECA CELLS. CORPUT LUTEUM PRODUCE  OESTROGEN PRGESTRONE ANDROGEN  LH RESPONSIBLE FOR DEVELOPMENT AND FUNCTION OF CORPUS LUTEUM PROGESTERONE PEAK= DAY 21 (8 DAYS AFTER OVULATION)  PEAK OF PROGESTERONE AND OESTROGEN INHIBIT   LH BY NEGATIVE FEEDBACK ON PITUITARY  AND THAT LEAD TO LUTEOLYSIS  LUTEAL PHASE= 14 DAYS CONSTANT  DEGENERATION ON 9-10 AFTER OVULATION  DROP IN PROGESTERONE AND OESTROGEN- MENSTRUATION  IF PREGNANCY, HCG (LH) SUPPORT CORPUS LUTEUM WHICH PRODUCE PROGSTRONE  -WHICH SUPPORT IMPLANTATION (7-8 WEEKS) 1 8 9 14 OVULATION PEAK DEGENERATION NEXT CYCLE FUNCTION HORMONAL CONTROL OF OVULATION ANTERIOR PITUITARY FOLLICLE STIMULATING HORMONES (FSH) LUTTEINZING HORMONE (LH) PROLACTIN GROWTH HORMONE (GH) ADRRENOCORTICOTROPHIC HORMONE (ACTH) THYROID STIMULATING HORMONE (TSH) MELANOEYTE STIMULATING HORMONE (MSH) FSH:  PROLIFERATION AND DIFFERENTAION OF GRANULOSE CELLS  FSH RECEPTORS ON GRANULOSE CELLS  STIMULATES STEROID SYNTHETIC ENZYMES: GRANULOSA CELLS  CYTOCHROME P 450-CHOLESTROL TO PROGESTERONE CYTOCHROME P 450 AROMATASE – THEACA CELLS ANDROGENS TO OESTOGEN  STIMULATES LH RECEPTORS SYNTHESIS- GRANULOSA CELLS  FSH+ OESTROGEN STIMULATE PROLIFERATION OF GRANULOSA CELLS OESTROGEN RISES, PEAPEAK STIMULATES LH SURGE POSITIVE FEEDBACK. LH:  PEAK 38 HOURS BEFORE OVULATION  PEAK STIMULATED BY OESTROGEN PEAK  RESUME FIRST MEIOTIC DIVISION OF OOCYTE  LEUTINIZATION OF GRANULOSA AND THECA CELLS  PGE2 PGF2Α SECRETED BY GRANULOSA CELLS  PLASMINOGEN TO PLASMIN  ACTIVATE OTHER ENZYMES  CORPUS LEUTUM DEVELOPMENT AND FUNCTION  FSH STIMULATES ITS RECEPTORS ON GRANULOSA CELLS GONODOTROPHIN RELEASING HORMONE (Gn RH)  SECRETED BY HYPOTHALAMUS- MEDIAL PRE-OPTIC AREA (CELL BODIES)  NERVE ENDINGS IN MEDIAN EMINENCE IN CLOSE PROXIMATY TO CAPILLARIES – ORIGIN OF HYPOPHYSEAL PORTAL TRACT.  Gn RH NEURONE DEVLOP IN NOSE AND MIGRATE TO HYPOTHALAMUS. FAILURE CAUSE KALLMANN'S SYNDROME HYPOGONADOTROPIC HYPOGONADISM AND ANOSMIA  STIMULATE ANTERIOR PITUITARY = FSH+LH  PULSATILE Gn RH AND PULSATILE LH AND NOT FSH.  CONTROL  NEURAL: HIGHER NEURAL CENTRES AFFECT SYNTHESIS AND RELEASE (NUTRITION- EMOTION- LIGHT- WEIGHT)  ENDOCRINE OESTROGEN AND PROGESTERONE INHIBIT GnRH BY NEGATIVE   FEEDBACK  POSITIVE FEEDBACK OF OESTROGEN LH SURGE BOTH ON GnRH AND ANTERIOR PITUITARY PROLACTIN:  SECRETED BY ANTERIOR PITUITARY  TONICALLY INHBITED BY DOPAMINE WHICH SECRETED BY THE HYPOTHALAMUS IN THE ARCUATE NUCLEUS  THYROTROPHIN RELEASING HORMONE STIMULATES PROLACTIN SECRETION (NO PHYSIOLOGICAL ROLE).  OSTROGEN STIMULATES PROLACTIN AT PITUITARY LEVEL. HYPERPROLACTINAEMIA:  PROLACTINOMA  HYPOTHYROIDISM  DOPAMINE ANTAGONIST – ANTIDEPRESSANTS HYPERPROLACTINAEMIA INHIBITS LH PULSATILITY LEADING TO AMENORRHOEA AND GLACTORRHOEA TREATED BY BROMOCREPTINE- DOPAMINE AGONIST. ACTIVATE THE DOPAMINERGIN RECEPTORS AND THUS INCREASE THE EFFECT OF NORMAL LEVEL OF DOPAMINE. INDUCTION OF OVULATION * USED ONLY IN TREATMENT OF INFERTILITY * OVARY MUST CONTAIN OOCYTES * TREAT OTHER DISEASES WHICH CAUSE ANOVULATION E.G. THYROID DISEASES DRUGS CLOMIPHENE CITRATE INTERFERE WITH NEGATIVE FEEDBACK OF OESTROGENS ON THE HYPOTHALAMUS AND PITUITARY. INCREASE RELEASE OF GnRH, LH, FSH. FSH: (HUMAN MENOPAUSAL GONADO TROPHIN HMG) LH (HUMAN CHORIONICGONADOTROPHIN HGG) BROMOCREPTINE GNRH EVIDENCE OF OVULATION 1. REGULAR CYCLES WITH SYMPTOMS 2. BIPHASIC TEMPERATURE CHART 0.5C0 AFTER OVULATION 3. COPIOUS CERVICAL MUCOUS, WATERY, ALKALINE, PENETRATED BY SPERMS, FERN TEST  ENDOMETRIAL BIOPSY- SECRETARY IN LUTEAL PHASE 5. PROGESTERONE DAY 21 6. LAPAROSCOPY – PREOVALATORY … 18-23 MM 7. RETRIEVAL OF OVA Menstruation:  Throughout the child bearing years of a woman's life rhythmic changes concerned with REPRODUCTION take place in a monthly cycle involving the hypothalamus, anterior pituitary, ovaries and endometrium.  Menstruation is the shedding of the superficial layers of the endometrium + blood.  It is a reflection of the ovarian events. Endometrium:  Formed of glands, arterioles, stroma.  3 layers:  Basalis: does not shed during menstruation and from it the endometrium regrowth.  Spongiosum functional layers  Compactum Follicular (Proliferatine) phase:  First 14 days.  Under the effect of oestradiol produced by the maturing ovarian follicle.  Grow from the basalis layer.  Growth of glands, stroma and arterioles. Luteal (Secretory) phase:  Second 14 days  Under effect of progesterone (+ oestrogen) produced by corpus luteum.  Growth arterioles, stroma and glands (secrete).  Ready for implantation of the fertilized ovum.  If pregnancy occurs the implanted ovum produces Human Chorionic Gonadotrophin (HCG) which rescue the corpus luteum → Progesterone → Endometrium → decidua. Menstruation:  If pregnancy does not occur, the corpus luteum regresses and WITHDRAWAL OF PROGESTRONE.  Prostaglandins which cause VASOCONSTRICION AND UTERINE CONTRACTION. → hypoxia of endometrium.  Shedding of endometrium + blood unclotted.  Menstrual blood  Formed of haemolysed blood, mucous, cellular depris.  40 ml / cycle.  Menarche 11-16 years (13).  Menopause 47-53 years (51).  Cycle 4/ 28.  Symptoms – pain + breast congestion + moode change.