Normal menstruation

Normal Normal menstruationmenstruation

Menstruation is the cyclic bleeding caused by Menstruation is the cyclic bleeding caused by shedding of the secretary endometrium due to shedding of the secretary endometrium due to decline in estrogen and progesterone cause by decline in estrogen and progesterone cause by regression of the corpus luteum .regression of the corpus luteum .This depends mainly on the functional integrity of This depends mainly on the functional integrity of three endocrine sources :-three endocrine sources :- 1- the hypothalamus1- the hypothalamus 2- the anterior pituitary gland 2- the anterior pituitary gland 3- the theca granulosa cells of the ovary 3- the theca granulosa cells of the ovary This often referred to as the hypothalamic – pituitary This often referred to as the hypothalamic – pituitary ovarian axis .ovarian axis .

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A neuro chemical transmitter known as A neuro chemical transmitter known as gonadotropin releasing hormone (GnRH) which gonadotropin releasing hormone (GnRH) which produced in the hypothalamus is liberated in a produced in the hypothalamus is liberated in a pulsatile fashion into the capillary plexus of the pulsatile fashion into the capillary plexus of the median eminence and is carried through the median eminence and is carried through the portal vessels to the anterior lobe of the pituitary portal vessels to the anterior lobe of the pituitary gland .the result of its neuro hormonal action is gland .the result of its neuro hormonal action is the production and release of the gonadotrophins the production and release of the gonadotrophins FSH and LH from the anterior pituitary cells , FSH and LH from the anterior pituitary cells , these hormones are transmitted to the ovary these hormones are transmitted to the ovary where they stimulate follicle development and where they stimulate follicle development and ovulation . ovulation .


Ovarian cycle :-Ovarian cycle :-

At the time menstruation is taking place At the time menstruation is taking place growthgrowth of a number of of a number of (100 -1000) (100 -1000) primordial ovarian follicles in both ovaries is primordial ovarian follicles in both ovaries is stimulated by FSH and to a lesser extend by LH and continue stimulated by FSH and to a lesser extend by LH and continue for 5 to 7 days this is called recruitment .for 5 to 7 days this is called recruitment .

Selection :Selection : Only one follicle is selected to reach maturity to form the Only one follicle is selected to reach maturity to form the

graafian follicle . graafian follicle . production of estradiol resulting from the increase of both production of estradiol resulting from the increase of both

FSH receptors and granulosa cells is responsible for this FSH receptors and granulosa cells is responsible for this process of process of selection selection

Dominance :Dominance :The The selected follicle ultimately becomes the dominant follicle selected follicle ultimately becomes the dominant follicle

over the next 5 days to form the graafian follicle by over the next 5 days to form the graafian follicle by suppressing the growth of the remaining follicles by secreting suppressing the growth of the remaining follicles by secreting sufficient estradiol and inhibin to suppress pituitary FSH . sufficient estradiol and inhibin to suppress pituitary FSH .

1- follicular phase :-

Recruitment :


The graafian follicle :The graafian follicle :

at the end of maturation at the end of maturation the graafian follicle is the graafian follicle is about 18-25 mm in about 18-25 mm in diameter and consists diameter and consists of :of :

- OvumOvum- Zona pellucidaZona pellucida- Corona radiata Corona radiata - Cumulus oophorusCumulus oophorus- Perivitelline spacePerivitelline space- Cavity filled with liquor Cavity filled with liquor

folliculi folliculi - Granulosa cellsGranulosa cells- Theca cellsTheca cells

ovum

Zona pellucida

Crona radiata

Liquor folliculiGranulosa cells

Theca cells


2- ovulation 2- ovulation

The estradiol level reachs its peak The estradiol level reachs its peak (200-300 pg/ml) (200-300 pg/ml)

about 48 hours before ovulation and lasting for about 48 hours before ovulation and lasting for 48 hours this lead to LH surge . 24 hours following 48 hours this lead to LH surge . 24 hours following LH surge the graafian follicle rupture . The ovum LH surge the graafian follicle rupture . The ovum being discharged into or very close the ostium of being discharged into or very close the ostium of the fallopian tube .the fallopian tube .

At ovulation the ovum has undergone the first At ovulation the ovum has undergone the first meiotic division reducing the number of meiotic division reducing the number of chromosomes from 46 to 23 and casting off the chromosomes from 46 to 23 and casting off the first polar body . The second maturation division first polar body . The second maturation division occurs after fertilization .occurs after fertilization .

At this time the ovum is surrounded by a pale At this time the ovum is surrounded by a pale staining zone the zona pellucida and out side this staining zone the zona pellucida and out side this is a ring of granulosa cells the corona radiata is a ring of granulosa cells the corona radiata www.doctor.sdwww.doctor.sd

Corpus haemorrhagcum :Corpus haemorrhagcum :

The rupture of the follicle and release of the ovum is The rupture of the follicle and release of the ovum is attended by capillary bleeding . The blood replaces attended by capillary bleeding . The blood replaces the follicular fluid and the remaining part of the the follicular fluid and the remaining part of the graafian follicle becomes the corpus graafian follicle becomes the corpus haemorrhagcum .haemorrhagcum .

Corpus luteum :Corpus luteum :

Through the continued action of LH the granulosa cells Through the continued action of LH the granulosa cells soon become luteinized and a corpus luteum result . soon become luteinized and a corpus luteum result . The granulosa cells and the theca interna cells The granulosa cells and the theca interna cells increases in size and take a swollen increases in size and take a swollen appearance .during this process fluid rich in appearance .during this process fluid rich in carotene is deposited within the cell cytoplasm carotene is deposited within the cell cytoplasm giving the corpus luteum an increasingly a yellow giving the corpus luteum an increasingly a yellow colour .as development proceed the cells of the colour .as development proceed the cells of the corpus luteum become thrown into folds as they corpus luteum become thrown into folds as they collapse into the empty cavity giving a characteristic collapse into the empty cavity giving a characteristic appearance .appearance .


The corpus luteum continues to grow and function The corpus luteum continues to grow and function aided by the pulsatile secretion of LH until about aided by the pulsatile secretion of LH until about day 23 or 24 of the cycle when it begins to regress . day 23 or 24 of the cycle when it begins to regress . If the ovum which was discharged at the time of If the ovum which was discharged at the time of ovulation is fertilized this regression does not take ovulation is fertilized this regression does not take place . The corpus luteum continues to function as place . The corpus luteum continues to function as the corpus luteum of pregnancy being maintained the corpus luteum of pregnancy being maintained by LH effect of HCG . in the absence of pregnancy by LH effect of HCG . in the absence of pregnancy the corpus luteum becomes progressively less the corpus luteum becomes progressively less sensitive to LH stimulation .sensitive to LH stimulation .

As the corpus luteum regresses it becomes As the corpus luteum regresses it becomes hyalinized and has a characteristic convoluted hyalinized and has a characteristic convoluted structure that can be seen histologicaly and called structure that can be seen histologicaly and called the corpus albicans . This concides with fall in the corpus albicans . This concides with fall in estrogen and progesterone until the endometrium estrogen and progesterone until the endometrium can not be maintained and menstruation occurs. can not be maintained and menstruation occurs.


The endometrial cycleThe endometrial cycle

1- proliferative phase :1- proliferative phase :- Immediately following menstruation the Immediately following menstruation the

endometrium is thin.glands are narrow and straight endometrium is thin.glands are narrow and straight and are lined by cuboidal epithelium , the stroma is and are lined by cuboidal epithelium , the stroma is compact .compact .

- The action of estrogen coming from the graafian The action of estrogen coming from the graafian follicle on this thin uterine lining is to produce follicle on this thin uterine lining is to produce growth of all elements Present. The glands become growth of all elements Present. The glands become longer but remain straight . The epithelium lining longer but remain straight . The epithelium lining becomes tall and columnar the nucli occuping a becomes tall and columnar the nucli occuping a basal position . The stroma cells increase in basal position . The stroma cells increase in number and become more loosely packed number and become more loosely packed together . together .

- The whole stroma being vascular and abundant .The whole stroma being vascular and abundant .- The endometrium is about 3-4 mm . The endometrium is about 3-4 mm .

The endometrial changes are divided into three phases


2- secretary phase :2- secretary phase :- Following ovulation and the addition of progesterone Following ovulation and the addition of progesterone

activity to estrogen effect (coming from the corpus luteum) activity to estrogen effect (coming from the corpus luteum) the glands become more tortuous and cork screw like .the glands become more tortuous and cork screw like .

- The epithelium lining demonstrates a series of changes The epithelium lining demonstrates a series of changes during which the nuclei become displaced from their basal during which the nuclei become displaced from their basal position towards the centre of the cell by the formation of position towards the centre of the cell by the formation of subnuclear vacules .subnuclear vacules .

- The glands lumina are seen to contain more secretion .as The glands lumina are seen to contain more secretion .as the days go by until maximum secretion is achieved about the days go by until maximum secretion is achieved about day 25-of a 28 days cycle .the secretion is rich in glycogen.day 25-of a 28 days cycle .the secretion is rich in glycogen.

- Stromal cells become further increase in size and are Stromal cells become further increase in size and are loosely arranged .loosely arranged .

- The endometrium become differentiated into three layers.The endometrium become differentiated into three layers.- 1\ the superficial compact layer around the neck of the 1\ the superficial compact layer around the neck of the

glands.glands.- 2\ middle spongy layer around the distended lumen of the 2\ middle spongy layer around the distended lumen of the

gland.gland.- 3\ deep compact layer around the basal part of the glands.3\ deep compact layer around the basal part of the glands.- The arterioles of the endometrium become more coiled .The arterioles of the endometrium become more coiled .- The endometrium thickness is about 6-8 mm. The endometrium thickness is about 6-8 mm.


3- menstrual bleeding phase :3- menstrual bleeding phase : With regression of the corpus luteum the levels of With regression of the corpus luteum the levels of

estrogen and progesterone in the blood fall and the estrogen and progesterone in the blood fall and the maintainence of the endometrium is maintainence of the endometrium is withdrawn ,shrinkage occurs and there is withdrawn ,shrinkage occurs and there is constriction of the spiral arterioles, stasis ,necrosis constriction of the spiral arterioles, stasis ,necrosis and bleeding .and bleeding .

The endometrium with the exception of the deeper The endometrium with the exception of the deeper basal zone which remain an effective blood supply basal zone which remain an effective blood supply breaks down and is cast off as menstrual flow.breaks down and is cast off as menstrual flow.

Concentration of prostaglandin F2Concentration of prostaglandin F2 alfa alfa increases increases through out the menstrual cyclethrough out the menstrual cycle . . the highest the highest amounts are measured at the time of menstrual amounts are measured at the time of menstrual flow this potent vasoconstrictor probably plays a flow this potent vasoconstrictor probably plays a key rote in initiating spiral arteriolar spasm .key rote in initiating spiral arteriolar spasm .

The endometrial surface diminishes to 1.25 mm The endometrial surface diminishes to 1.25 mm during this phase in a course of several hours . during this phase in a course of several hours .



Clinical aspects of normal menstruationClinical aspects of normal menstruation

Age of onset of menstruation (menarche) :Age of onset of menstruation (menarche) : - the first period usually occur at about 12 yrs - the first period usually occur at about 12 yrs

, but menses may appear at the age of 10 or , but menses may appear at the age of 10 or may be delayed until 16 without being may be delayed until 16 without being considered abnormal considered abnormal

- Many factors are responsible for this wide Many factors are responsible for this wide variation . The most significant are race, variation . The most significant are race, heredity , the general health , nutrition status heredity , the general health , nutrition status and the body mass of the individual girl .and the body mass of the individual girl .

- Before 10 yrs its called precocious Before 10 yrs its called precocious menstruation menstruation

- After 16 yrs its called delayed menstruation .After 16 yrs its called delayed menstruation .www.doctor.sdwww.doctor.sd

Cycle length :Cycle length :- The normal interval from the begining - The normal interval from the begining

of one period to the onset of the next of one period to the onset of the next period is 28 + 7 days (21 -35)period is 28 + 7 days (21 -35)

- The postovulatory phase is constant at The postovulatory phase is constant at 14 + 2 days where as the preovulatory 14 + 2 days where as the preovulatory interval be as short as 3 or 4 days or as interval be as short as 3 or 4 days or as long as 21 days .long as 21 days .

- Patient with short cycle less than 21 Patient with short cycle less than 21 days are said to have polymenorrhoea .days are said to have polymenorrhoea .

- If the cycle interval are long (45 – 60) If the cycle interval are long (45 – 60) the condition is called oligomenorrhoea the condition is called oligomenorrhoea

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Duration of flow :-Duration of flow :-- The usual length of flow is 5 + 2 days (3-7) The usual length of flow is 5 + 2 days (3-7) - Extremely short or scanty periods are called Extremely short or scanty periods are called

hypomenorrhoea .hypomenorrhoea .- Where as unusually long or profuse menses are Where as unusually long or profuse menses are

referred to as hypermenorrhoea (menorrhagia) referred to as hypermenorrhoea (menorrhagia) Amount of flow :-Amount of flow :-- the amount of loss at each period varies greatly . the amount of loss at each period varies greatly .

The average is about 40 ml + 2o ml The average is about 40 ml + 2o ml - A loss more than 80 ml is considered abnormal A loss more than 80 ml is considered abnormal

(menorrhagia) (menorrhagia) Character of flow :-Character of flow :-- The menstrual discharge consist of blood rich in The menstrual discharge consist of blood rich in

leucocytes , mucus and desquamated particles of leucocytes , mucus and desquamated particles of endometrium .endometrium .

- It is usually dark red and has characteristic musty It is usually dark red and has characteristic musty odor and do not clot under normal odor and do not clot under normal circumstances .circumstances .

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fertilizationfertilization FertilizationFertilization Is the process of fusion of the spermatozoon with Is the process of fusion of the spermatozoon with

the mature ovum.the mature ovum. It begins with sperm egg collision and end with It begins with sperm egg collision and end with

production of a mononuclear single cell called the production of a mononuclear single cell called the zygote and result in restoration of the zygote and result in restoration of the chromosomes number to 46 pairs.chromosomes number to 46 pairs.

Almost always fertilization occurs in the Almost always fertilization occurs in the ampullary part of the uterine tubes.ampullary part of the uterine tubes.

Immediately following ovulation the ovum is Immediately following ovulation the ovum is picked up by the tubal fimbriae which partly picked up by the tubal fimbriae which partly envelope the ovary. The pick up action might be envelope the ovary. The pick up action might be muscular, or a kind of suction or by ciliary action muscular, or a kind of suction or by ciliary action or chemotaxis exerted by the tube secretion.or chemotaxis exerted by the tube secretion.

The ovum is rapidly trasported to the ampullary The ovum is rapidly trasported to the ampullary part of the tube .part of the tube .


Out of hundreds of millions of sperms deposited in Out of hundreds of millions of sperms deposited in the vagina only thousands enter the uterine tube the vagina only thousands enter the uterine tube while only about 300 to 500 reach the ovum .it while only about 300 to 500 reach the ovum .it takes one hour for the sperm to reach its site.takes one hour for the sperm to reach its site.

Complete dissolution of the cells of the corona Complete dissolution of the cells of the corona radiata occurs probably by the chemical action of radiata occurs probably by the chemical action of the hyaluronidase enzyme liberated from the the hyaluronidase enzyme liberated from the acrosomal cap of the hundreds of sperms present acrosomal cap of the hundreds of sperms present at the site or by the action of mucosal enzymes .at the site or by the action of mucosal enzymes .

More than one sperm may penetrate the zona More than one sperm may penetrate the zona pellucida . This penetration is probably facilitated pellucida . This penetration is probably facilitated by the release of hyaluronidase enzymes from by the release of hyaluronidase enzymes from sperm acrosomal cap . Only one sperm touches the sperm acrosomal cap . Only one sperm touches the vitalline membrane . Soon penetration of the other vitalline membrane . Soon penetration of the other sperms is prevented by zonal reaction and vitelline sperms is prevented by zonal reaction and vitelline block . block .


- - Completion of the second meiotic division of the Completion of the second meiotic division of the oocyte immediatly follows with formation of two oocyte immediatly follows with formation of two cells each has haploid number of chromosomes cells each has haploid number of chromosomes (23x) the bigger one is called the female (23x) the bigger one is called the female pronucleus and the small one is called second pronucleus and the small one is called second polar body which is pushed to the perivitelline polar body which is pushed to the perivitelline space space

- The head and neck of the spermatozoon become The head and neck of the spermatozoon become male pronucleus containig hapliod number of male pronucleus containig hapliod number of chromosomes (23x) or (23y) chromosomes (23x) or (23y)

- The male and female pronuclei unite to form the The male and female pronuclei unite to form the zygote with restoration of the diploid number of zygote with restoration of the diploid number of chromosomes (46xx) or (46xy) chromosomes (46xx) or (46xy)

- Sex of the child is determined by the pattern of Sex of the child is determined by the pattern of the sex chromosomes supplied by the the sex chromosomes supplied by the spermatozoon . If the spermatozoon contain x spermatozoon . If the spermatozoon contain x chromosome a female embryo (46xx) is formed if chromosome a female embryo (46xx) is formed if it contain a y chromosome a male embryo (46xy) it contain a y chromosome a male embryo (46xy) is formed . is formed .


- after the zygote formation typical mitotic division after the zygote formation typical mitotic division of the nucleus occurs producing two blastomeres . of the nucleus occurs producing two blastomeres . This two cells stage is reached approximately 30 This two cells stage is reached approximately 30 hours after fertilization each contain equal hours after fertilization each contain equal cytoplasmic volume and chromosome numbers .cytoplasmic volume and chromosome numbers .

- the blastomeres continue to divide by binarry the blastomeres continue to divide by binarry division through 4,8,16 cells stage until a cluster division through 4,8,16 cells stage until a cluster of cells is formed and is called morula of cells is formed and is called morula

- The morula after spending about 3 day in the The morula after spending about 3 day in the uterine tube enters the uterine cavity .uterine tube enters the uterine cavity .

- The central cells of the morula is known as inner The central cells of the morula is known as inner cells mass which forms the embryo proper and the cells mass which forms the embryo proper and the peripheral cells are called the outer cells mass peripheral cells are called the outer cells mass which will form protective and nutritive membrane which will form protective and nutritive membrane of the embryo .of the embryo .


- While the morula remains free in the uterine While the morula remains free in the uterine cavity on the 4cavity on the 4thth and 5 and 5thth day it is covered by a film day it is covered by a film of mucus . The fluid passes through the canaliculi of mucus . The fluid passes through the canaliculi of the zona pellucida which separates the cells of of the zona pellucida which separates the cells of the morula and is now termed blastocyst the morula and is now termed blastocyst

- Implantation occurs at this blastocyst stage , 6 to Implantation occurs at this blastocyst stage , 6 to 8 days after ovulation . 8 days after ovulation .


Health & Medicine

Normal menstruation