Female Female Genital Genital SystemSystem

One ovum in an ovary ripens each month. One ovum in an ovary ripens each month.

Around the ovum the sac-like follicle which Around the ovum the sac-like follicle which absorbs fluid, grows and swells for about absorbs fluid, grows and swells for about fourteen days until it bursts onto the surface fourteen days until it bursts onto the surface of the ovary and the mature ovum, is of the ovary and the mature ovum, is released.released.

After ovulation, the empty follicle forms the After ovulation, the empty follicle forms the hormone-producing corpus luteum, which hormone-producing corpus luteum, which helps to maintain pregnancy if fertilization helps to maintain pregnancy if fertilization occurs.occurs.

If fertilization does not occur the corpus If fertilization does not occur the corpus luteum simply withers away.luteum simply withers away.

Immature sex cells, or oogonia, Immature sex cells, or oogonia,

in the ovary divide by mitosis to in the ovary divide by mitosis to produce oocytes. produce oocytes.

Before ovulation, one oocyte divides Before ovulation, one oocyte divides by meiosis to produce a secondary by meiosis to produce a secondary oocyte with half the full number of oocyte with half the full number of chromosomes, and a polar body. chromosomes, and a polar body.

At fertilization, further divisions At fertilization, further divisions result in the production of the result in the production of the mature ovum and three superfluous mature ovum and three superfluous polar bodies.polar bodies.

Controlled by hormones, the Controlled by hormones, the average menstrual cycle is twenty-average menstrual cycle is twenty-eight days. eight days.

From about day 5 pituitary follicle-From about day 5 pituitary follicle-stimulating hormone, or FSH, stimulating hormone, or FSH, promotes the growth of a follicle in promotes the growth of a follicle in the ovary. the ovary.

Follicular cells produce estrogen, Follicular cells produce estrogen, which builds up the endometrium, which builds up the endometrium, the uterine lining, in readiness for the uterine lining, in readiness for implantation of the fertilized egg. implantation of the fertilized egg. In midcycle, a surge of pituitary In midcycle, a surge of pituitary luteinizing hormone, or LH, causes luteinizing hormone, or LH, causes ovulation.ovulation.

The corpus luteum secretes The corpus luteum secretes

progesterone, which reinforces progesterone, which reinforces estrogen and builds up the estrogen and builds up the endometrium to its maximum endometrium to its maximum thickness.thickness.

If the ovum is not fertilized, the If the ovum is not fertilized, the

corpus luteum degenerates in corpus luteum degenerates in the last few days of the cycle the last few days of the cycle and the lining is shed during and the lining is shed during

menstruation, which marks the menstruation, which marks the start of a new cycle. start of a new cycle.

If fertilization occurs, about day 14 If fertilization occurs, about day 14 the fertilized egg secretes human the fertilized egg secretes human chorionic gonadotrophin, or HCG. chorionic gonadotrophin, or HCG.

This maintains the corpus luteum This maintains the corpus luteum

and its output of progesterone and and its output of progesterone and estrogen so that the endometrium estrogen so that the endometrium is maintained during pregnancy and is maintained during pregnancy and menstruation does not occur.menstruation does not occur.

The endometrium then nourishes The endometrium then nourishes the fertilized eggthe fertilized egg..

o The immature egg is released into the The immature egg is released into the Fallopian tube after undergoing the first Fallopian tube after undergoing the first meiotic division and formation of the first meiotic division and formation of the first polar body. polar body.

o The egg consists of a nucleus and The egg consists of a nucleus and cytoplasm enclosed in the vitelline cytoplasm enclosed in the vitelline membrane and surrounded by the zona membrane and surrounded by the zona pellucida, which is itself covered by a layer pellucida, which is itself covered by a layer of loose cells, the corona radiata. of loose cells, the corona radiata.

o The sperm passes through all these layers The sperm passes through all these layers to reach the nucleus of the egg, and on to reach the nucleus of the egg, and on penetration of the egg it stimulates the penetration of the egg it stimulates the second meiotic division of the ovum and the second meiotic division of the ovum and the formation of a second polar body.formation of a second polar body.

Menstrual cycle is acyclic change in Menstrual cycle is acyclic change in ovaries, uterus, cervix, vagina & breastovaries, uterus, cervix, vagina & breast

11 - -Ovarian cycleOvarian cycle: : Primordial folliclesPrimordial follicles..Growth under control of FSHGrowth under control of FSHA-Follicular phaseA-Follicular phaseHypo-pit-axis (FSH-LH)Hypo-pit-axis (FSH-LH)There is changes in other organsThere is changes in other organs

Granulosa cells _ FSH / EstrogenGranulosa cells _ FSH / EstrogenThece cells (int.-ext.) – LH / AndrogenThece cells (int.-ext.) – LH / Androgen

-(-(veve ) )feedbackfeedback..

22 - -ovulatory phaseovulatory phase::Increase Est – (+ve)fb on FSH / LH “peakIncrease Est – (+ve)fb on FSH / LH “peak””

Ovulation occurs after LH peakOvulation occurs after LH peakIn ovulation temprature increase (+0.5 c)In ovulation temprature increase (+0.5 c)

14-1514-15 dayday..

33--Luteal phaseLuteal phase::

LH acts on follicular cells after ovulationLH acts on follicular cells after ovulation

Follicles – corpus luteum secretes Follicles – corpus luteum secretes Est,ProgEst,Prog

FSH, LH drop – (-ve)fbFSH, LH drop – (-ve)fb

No pregnancy – Est,Prog drop – FSH,LH No pregnancy – Est,Prog drop – FSH,LH increase – new ovulation occursincrease – new ovulation occurs

Pregnancy _ hCG sec – maintains CLPregnancy _ hCG sec – maintains CL

UTERINE CYCLEUTERINE CYCLE::ChangeChange in in endometriumendometrium

11 - -Proliferative phase : (follicular phase)Proliferative phase : (follicular phase)Menstruation- ovulationMenstruation- ovulationEst dependent - thickness 0.5- 5mmEst dependent - thickness 0.5- 5mmArteries straight, glands tubularArteries straight, glands tubular

22 - -Secretary phase:(leuteal phase)Secretary phase:(leuteal phase)Ovulation-menstruationOvulation-menstruationProg dependentProg dependent

33 - -menstrual phasemenstrual phase: : Loss of endometriumLoss of endometriumBleeding 3-5 days (no clot)Bleeding 3-5 days (no clot)

- -Change in cervixChange in cervixProf : mucus thinProf : mucus thinSec : thickSec : thick

11 - -EstrogenEstrogen::

Steroid H (granulosa cells / placenta )Steroid H (granulosa cells / placenta )

ActionsActions::

. .Secondary charc. Of femaleSecondary charc. Of female

. .Menstrual cycleMenstrual cycle

. .Increase ductular tissue of breastIncrease ductular tissue of breast

. .Increase clotting factorIncrease clotting factor

22 - -Progesteron :(ovaries / placenta )Progesteron :(ovaries / placenta )

Steroid HSteroid H

ActionsActions::

. .Cyclic changesCyclic changes

. .Increase growth of alveolar tissueIncrease growth of alveolar tissue

. .Theromgenic effect (BMR)Theromgenic effect (BMR)

. .Inhibits oxytocin – no contractionInhibits oxytocin – no contraction

33 - -hCG (human chorionic hCG (human chorionic gonadotropin)gonadotropin)::

placentaplacenta

. .Maintains corpus luteumMaintains corpus luteum

. .Detection of pregnancyDetection of pregnancy

66 days after implatation – blooddays after implatation – blood

1414 days - urinedays - urine

44 - -hCS (human chorionic hCS (human chorionic somatomammotropin)somatomammotropin)::

. .Stimulates growth & milk productionStimulates growth & milk production

55 - -RelaxinRelaxin: :

..Maintains pregnancy(inhibits uterine Maintains pregnancy(inhibits uterine contraction)contraction)

. .Facilitate delivery ( relaxes of ligaments )Facilitate delivery ( relaxes of ligaments )

The five-month embryo is about eight inches The five-month embryo is about eight inches long and weighs about half a pound. long and weighs about half a pound.

The lungs and digestive organs are not yet The lungs and digestive organs are not yet fully developed. fully developed.

The mother can now feel the baby as it turns The mother can now feel the baby as it turns and kicks. At seven months the fetus is about and kicks. At seven months the fetus is about twelve inches long and weighs two to three twelve inches long and weighs two to three pounds. pounds.

Calcium and iron from the mother are being Calcium and iron from the mother are being used in the final formation of the skeleton and used in the final formation of the skeleton and the blood. the blood.

At nine months the fetus, now capable of an At nine months the fetus, now capable of an independent existence, moves into a vertical independent existence, moves into a vertical head-down position facing the mother's back. head-down position facing the mother's back.

At birth the baby usually weighs between six At birth the baby usually weighs between six and eight pounds.and eight pounds.

During childbirth the baby lies in the mother's During childbirth the baby lies in the mother's uterus with his head pointing down toward the uterus with his head pointing down toward the cervix.cervix.

The first stages of labor begin with short, regular The first stages of labor begin with short, regular contractions of the uterus, every few minutes, contractions of the uterus, every few minutes, which continue until the mother's cervix is fully which continue until the mother's cervix is fully dilated.dilated.

In the second stage of labor the contractions In the second stage of labor the contractions become more forceful, more frequent, and more become more forceful, more frequent, and more painful. As the baby's head starts to move down painful. As the baby's head starts to move down the vagina the amniotic sac breaks and fluid is the vagina the amniotic sac breaks and fluid is released. released.

The top of the head appears at the entrance of The top of the head appears at the entrance of the vagina and finally bulges out. This is the the vagina and finally bulges out. This is the crowning of the head. The contractions which crowning of the head. The contractions which follow push the baby even farther down so that follow push the baby even farther down so that the head is delivered.the head is delivered.

The baby usually emerges facing the mother's The baby usually emerges facing the mother's back, so that the head passes through the widest back, so that the head passes through the widest possible opening in the pelvic girdle.possible opening in the pelvic girdle.

Uterine contractions at birth are Uterine contractions at birth are strengthened by oxytocin, a pituitary strengthened by oxytocin, a pituitary hormone. hormone.

During pregnancy, progesterone During pregnancy, progesterone makes the uterus relatively makes the uterus relatively unresponsive to oxytocin. unresponsive to oxytocin.

Reflexes in the cervix during labor Reflexes in the cervix during labor strengthen uterine contraction and strengthen uterine contraction and oxytocin output increases. oxytocin output increases.

The progesterone levels falls, The progesterone levels falls, oxytocin becomes effective, and the oxytocin becomes effective, and the baby is pushed out.baby is pushed out.