Female reproductive Female reproductive systemsystem

Atretic follicle:Atretic follicle:

Most ovarian follicles undergo atrasia, in which the follicular Most ovarian follicles undergo atrasia, in which the follicular cells and oocytes dies and engulfed by phagocytic cells. cells and oocytes dies and engulfed by phagocytic cells. Follicles at any stage of development may undergo atrasia and Follicles at any stage of development may undergo atrasia and this process is characterized by:this process is characterized by:

cessation of mitosis in granulose cellscessation of mitosis in granulose cells

detachment of granulose cells from the basal laminadetachment of granulose cells from the basal lamina

death of the oocytesdeath of the oocytes

after cell death macrophages will invade the follicle & after cell death macrophages will invade the follicle & phagocytose its debris.phagocytose its debris.

at later stages fibroblasts will at later stages fibroblasts will

occupy the area of follicle & occupy the area of follicle &

produce a scar of collagen called produce a scar of collagen called

corpus fibrosum, that may persist corpus fibrosum, that may persist

for a long time.for a long time.

atrasia is most prominent after atrasia is most prominent after

birth when the effect of maternal birth when the effect of maternal

hormones cease & during puberty hormones cease & during puberty

& pregnancy when marked & pregnancy when marked

hormonal modifications occur.hormonal modifications occur.

Ovulation:Ovulation:

At ovulation the graffian follicle is so large that it distort the At ovulation the graffian follicle is so large that it distort the surface of the ovary, even it appear to the naked eye as a small surface of the ovary, even it appear to the naked eye as a small cystic mass bulging from the ovarian surface covered by only cystic mass bulging from the ovarian surface covered by only thin layer of germinal epithelium & a very thin layer of thin layer of germinal epithelium & a very thin layer of

cortical stroma. cortical stroma.

The stimulus for ovulation is a surge of LH which will also The stimulus for ovulation is a surge of LH which will also induce completion of the 1st stage of meiosis.induce completion of the 1st stage of meiosis.

Before ovulation the oocyte will break free from its Before ovulation the oocyte will break free from its

attachment to the follicular wall & float freely in the follicular attachment to the follicular wall & float freely in the follicular fluid surrounded by corona radiate.fluid surrounded by corona radiate.

At ovulation weakness in the wall of the follicle plus an At ovulation weakness in the wall of the follicle plus an

increased follicular fluid pressure will lead to rupture of the increased follicular fluid pressure will lead to rupture of the follicle & ovulationfollicle & ovulation

An indication for impending ovulation is the appearance of An indication for impending ovulation is the appearance of stigma on the surface of the follicle in which the blood flow stigma on the surface of the follicle in which the blood flow ceases resulting in local changes in color & translucence of the ceases resulting in local changes in color & translucence of the

follicular wall.follicular wall.

With ovulation the oocytes with its 1st polar body enclosed by With ovulation the oocytes with its 1st polar body enclosed by the zona pellucida plus the corona radiate & some follicular the zona pellucida plus the corona radiate & some follicular fluid will leave the ovary & enter the uterine tube where it will fluid will leave the ovary & enter the uterine tube where it will be fertilizedbe fertilized..

Ovulation occur approximately in the middle of the menstrual Ovulation occur approximately in the middle of the menstrual cycle (around the day 14 of a 28 day cycle). Usually only one cycle (around the day 14 of a 28 day cycle). Usually only one oocytes is liberated with each cycle but some times no oocytes oocytes is liberated with each cycle but some times no oocytes is ovulated at all (unovulatory cycle), some times 2 or more is ovulated at all (unovulatory cycle), some times 2 or more oocytes can be expelled at the same time & if they are oocytes can be expelled at the same time & if they are

fertilized there may be two or more fetuses. This occur mainly fertilized there may be two or more fetuses. This occur mainly with the use of ovulation inducing drugs.with the use of ovulation inducing drugs.

With ovulation slight bleeding from the highly vascular theca With ovulation slight bleeding from the highly vascular theca interna occur with release of this slight amount of blood & interna occur with release of this slight amount of blood & follicular fluid into the peritoneal cavity & this is thought to be follicular fluid into the peritoneal cavity & this is thought to be

responsible for the transient mid cycle lower abdominal pain responsible for the transient mid cycle lower abdominal pain at day 14-16 experienced by some women.at day 14-16 experienced by some women.

Corpus Luteum:Corpus Luteum:After ovulation the granulose After ovulation the granulose cells & the cells of the theca cells & the cells of the theca interna layer reorganize interna layer reorganize themselves to form a temporary themselves to form a temporary endocrine organ called corpus endocrine organ called corpus luteum which become embedded luteum which become embedded within the cortical region.within the cortical region.

The clot filled lumen of the The clot filled lumen of the follicle that results from ovulation follicle that results from ovulation will undergo progressive will undergo progressive organization & the blood will organization & the blood will coagulate & then invaded by coagulate & then invaded by connective tissues to form the connective tissues to form the center of corpus luteum.center of corpus luteum.

The granulose cells will increase The granulose cells will increase greatly in size & they make about greatly in size & they make about

80% of the parenchyma of the 80% of the parenchyma of the corpus luteum & now these cells corpus luteum & now these cells are called granulose lutein cells are called granulose lutein cells

these are large cells with these are large cells with abundant smooth endoplasmic abundant smooth endoplasmic

reticulum & they are distended reticulum & they are distended with lipid droplets (features with lipid droplets (features characteristic for steroid secreting characteristic for steroid secreting

cells) they secret progesteronecells) they secret progesterone..

Cells of theca interna also increase in Cells of theca interna also increase in size & accumulate lipid & called size & accumulate lipid & called theca lutein cells, these cells continue theca lutein cells, these cells continue to secrete estrogen & they stain more to secrete estrogen & they stain more intensely then the granulose cells. intensely then the granulose cells.

Fibrous septa partly separate the Fibrous septa partly separate the granulose lutein mass & clusters of granulose lutein mass & clusters of theca lutein cells are particularly theca lutein cells are particularly prominent in the region of these prominent in the region of these septa.septa.

At its maximum size (usually at day At its maximum size (usually at day 20 of the cycle) the corpus luteum is 20 of the cycle) the corpus luteum is an ovoid structure up to 2 cm. long & an ovoid structure up to 2 cm. long & 1.5 cm. width.1.5 cm. width.

Fate of corpus luteum:Fate of corpus luteum:

Depend whether pregnancy is established or not. The corpus luteum is Depend whether pregnancy is established or not. The corpus luteum is

programmed to act for 10-12 days after its formation. Its action is programmed to act for 10-12 days after its formation. Its action is

stimulated by the presence of LH.stimulated by the presence of LH.

if no further hormonal stimulation occur (decrease in LH concentration) & if no further hormonal stimulation occur (decrease in LH concentration) &

pregnancy doesn’t occur the cells of corpus luteum start to degenerate . so pregnancy doesn’t occur the cells of corpus luteum start to degenerate . so

there will be decrease in the granulose & theca lutein cells with the there will be decrease in the granulose & theca lutein cells with the

appearance of vacules on their cytoplasm, this will lead to gradual decrease appearance of vacules on their cytoplasm, this will lead to gradual decrease

in progesterone & estrogen concentration in the blood with its effect on the in progesterone & estrogen concentration in the blood with its effect on the

endometrium. endometrium.

Macrophages will phagocytose Macrophages will phagocytose the cellular debries of the corpus the cellular debries of the corpus

luteum & near by fibroblasts will luteum & near by fibroblasts will produce collagen fibers to fill the produce collagen fibers to fill the space & form a scar tissue called space & form a scar tissue called

corpus albicans. The corpus corpus albicans. The corpus luteim that lasts only part of the luteim that lasts only part of the

menstrual cycle & then menstrual cycle & then degenerate is called Corpus degenerate is called Corpus luteum of menstruation.luteum of menstruation.

If pregnancy occur:If pregnancy occur:

After implantation of the embryo & formation of trophoblat cells a signal After implantation of the embryo & formation of trophoblat cells a signal to the corpus luteum is given by the human choriouic gonadotropin to the corpus luteum is given by the human choriouic gonadotropin (secreted by the trophoblastic cells & have a similar action to LH).(secreted by the trophoblastic cells & have a similar action to LH).

Thus H.C.G will rescue the corpus luteum from degeneration & further Thus H.C.G will rescue the corpus luteum from degeneration & further growth of corpus luteum occur with more secretion of progesterone & it growth of corpus luteum occur with more secretion of progesterone & it is called corpus luteum of pregnancy, this structure persist for 4-5 months is called corpus luteum of pregnancy, this structure persist for 4-5 months & then degenerate & replaced by corpus albicans. & then degenerate & replaced by corpus albicans.

Progesterone secretion during pregnancy will:Progesterone secretion during pregnancy will:

maintain the uterine mucosa through out pregnancy.maintain the uterine mucosa through out pregnancy.

stimulate secretion of uterine glands important for the nutrition of the stimulate secretion of uterine glands important for the nutrition of the embryo before the placenta is functional.embryo before the placenta is functional.

Oviduct : ( uterine tubes)Oviduct : ( uterine tubes)

Are two muscular tubes of great Are two muscular tubes of great mobility. Each one is about 12 mobility. Each one is about 12 cm. in length & they are the site cm. in length & they are the site of fertilization of the ovum by of fertilization of the ovum by spermatozoa.spermatozoa.

There are four recognizable tubal There are four recognizable tubal segments, each one differ in its segments, each one differ in its histological features particularly histological features particularly in their proportion of muscle & in their proportion of muscle & epithelium & the degree of epithelium & the degree of convolution of their epithelium. convolution of their epithelium.

These segments are:These segments are:

infundibulum: which is the dilated open end of the tube near infundibulum: which is the dilated open end of the tube near the ovary with a finger like extensions called fimbriae.the ovary with a finger like extensions called fimbriae.

Ampulla: is a thin walled zone where fertilization of the ovum Ampulla: is a thin walled zone where fertilization of the ovum takes place usually.takes place usually.

Isthmus: it is the narrower thick walled segmentIsthmus: it is the narrower thick walled segment

Intramural segment: which passes through the wall of the Intramural segment: which passes through the wall of the

uterus & opens into the interior of the uterus.uterus & opens into the interior of the uterus.

The wall of the oviduct is The wall of the oviduct is formed of three layers:formed of three layers:

– MucosaMucosa

– thick muscularis layer thick muscularis layer (inner circular & outer (inner circular & outer longitudinal)longitudinal)

– serosa composed of serosa composed of the visceral peritoneumthe visceral peritoneum

Mucosa of the uterine tubes:Mucosa of the uterine tubes:

Has a longitudinal folds that are most Has a longitudinal folds that are most numerous in the ampulla, these folds numerous in the ampulla, these folds become smaller & less numerous in the become smaller & less numerous in the segments of the tube that are closer to the segments of the tube that are closer to the uterus. In the intramural segment the folds uterus. In the intramural segment the folds are very much reduced & the internal are very much reduced & the internal surface is almost smooth.surface is almost smooth.

Microscopically: the ampulla appear to Microscopically: the ampulla appear to have a thin muscular wall & a large lumen have a thin muscular wall & a large lumen with extensive mucosal folds while the with extensive mucosal folds while the isthmus appear to have a much thicker isthmus appear to have a much thicker muscular wall with small lumen & less muscular wall with small lumen & less marked mucosal folds.marked mucosal folds.

Cells of the surface epithelium:Cells of the surface epithelium:

ciliated cellsciliated cells: particularly numerous near the ovarian end of the tube : particularly numerous near the ovarian end of the tube where they form about 80% of the surface epithelium but near the uterus where they form about 80% of the surface epithelium but near the uterus form only about 25%. These cells are tall columnar cells, the hight of form only about 25%. These cells are tall columnar cells, the hight of these cells & number of cilia become more prominent at time of these cells & number of cilia become more prominent at time of ovulation, after that time these cells progressively shortens & loose ovulation, after that time these cells progressively shortens & loose some cilia until menstruation (this is mainly progesterone effect), & a some cilia until menstruation (this is mainly progesterone effect), & a similar changes are found through out pregnancy, while after similar changes are found through out pregnancy, while after menstruation & with the increase in estrogen level these cells increase in menstruation & with the increase in estrogen level these cells increase in hight & become more ciliated.these cells are responsible for the hight & become more ciliated.these cells are responsible for the movement of the ovum through out the tube to ward the uterine cavity.movement of the ovum through out the tube to ward the uterine cavity.

secretory cellssecretory cells: they produce a watery fluid which is assumed to have a : they produce a watery fluid which is assumed to have a nutritive function for the spermatozoa & the ovum. It will also activate nutritive function for the spermatozoa & the ovum. It will also activate the process of capacitation of the spermatozoathe process of capacitation of the spermatozoa..