Female reproductive system organs and description about cervix

Female reproductive system organs and description 

The internal genital in female are located in pelvis. The sex gland or ovary is comfortably located in the lateral pelvic wall and can withstand the body temperature during o genesis. Its counterpart, the testis in the male which needs lower temperature for spermatozoa genesis is made to hang out side the abdominal cavity. Fallopian tube connects the ovary with the uterus and carries the secondary  octette in the hope of getting it fertilized, to be nurtured in the muscular organ, the uterus for a period of nine months. The process of parturition, i.e. normal delivery of the baby, is a miracle of nature and is believed only after watching the agonizing process. The love and affection which a mother gives in bringing up a baby is insurmountable and unimaginable. That is why it is said '' Since God could not be everywhere, He created Mothers''. We thrive in this world because of these angel moms.

Ovaries 

The ovaries are the female gonads. The female gametes, called oocytes, are formed in them. Each ovary lies in the ovarian fossa on the lateral pelvic wall. Sex of the embryo is detarmined at the time of fertilization. The chromosomal complement in female is 'XX'. Various components of ovary are germs cells, follicular cells and the stromal cells. Germ cells get migrated from the dorsocaudal end of the yolk sac. Follicular cells are derived from the epithelial cells of the coelomic epithelium, while stromal cells are derived from mesoderm. There is no tunica albuginea in the ovary and the cortical part of the gonad predominates.Ovary descends down till the pelvis. Its descent is interrupted due to the presence of the single uterus, which divides the gubernaculum into ligament of ovary and round ligament of uterus.
Position : The position of the ovary is variable. In nulliparous women, its long axis is nearly vertical, so that the ovary is usually described as having an upper pole and a lower pole. However, in multiparous women, the long axis becomes horizontal; so that the upper pole points laterally and the lower pole medially.

Relations

Peritoneal relations : The ovary is almost entirely covered with peritoneum. except along the mesovarian or anterior border where the two layers of the covering peritoneum are reflected on to the posterior layer of the broad ligament of the uterus. the ovary is connected to the posterior layer of the broad ligament by a short fold of peritoneum, called the mesovarium. The squamous epithelium of the mesovarium is continuous with the cubical epithelium of the ovary. The mesovarium transmits the vessels and nerves to and from the ovary. The lateral part of the broad ligament of uterus, extending from the infundibulum of the uterine tube.
and the upper pole of the ovary, to the external iliac vessels, forms a distinct fold known as suspensory ligament of the ovary or infundibulopelvic ligament. It contains the ovarian vessels and nerves.

Arterial supply and nerve supply :The ovarian artery arises from the abdominal aorta just below the renal artery. It descends over the posterior abdominal wall and enters the suspensory ligament of the ovary. It sends branches to the ovary through the mesovarium, and continus medially through the broad ligament of the uterus to anastomose with the uterine artery. In addition to ovary, the ovarian artery also supplies the uterine tube, the side of uterus and the ureter. The uterine artery gives some branches which reach the ovary through the mesovarium. The ovarian plexus, derived from the renal, aortic and hypogastric plexuses, accompanies the ovarian artery. It contains both sympathetic and parasympathetic nerves. Sympathetic nerves are afferent for pain as well as efferent or vasomotor. Parasympathetic nerves are vasodilator.

Subdivisions

The lateral end of the uterine tube is shaped like a funnel and is, therefore, called the infundibulum. It bears a number of fingerlike processes called fimbriae and is, therefore, called the fimbriated end. One of the fimbriae is longer then the others and is attached to the tubal pole of the ovary. It is known as the ovarian fimbria. The part of the uterine tube medial to the infundibulum is called the ampulla. It is thinwalled, dilated and tortuous, and forms approximately the lateral two-thirds or 6 to 7 cm of the tube. It arches over the upper pole of the ovary. The ampulla is about 4mm in diameter. The isthmus succeeds the ampulla. It is narrow rounded and cord-like, and forms approximately the medial one-third or 2 to 3 cm of the tube. The uterine or intramural or interstitial part of the tube is about 1 cm long and lies within the wall of the uterus. It opens at the superior angle of the uterine cavity by a narrow uterine ostium. This ostium is about 1mm in diameter.

Uterus
In layman's language, the uterus is called the womb. It is also called hystera, on which word hysterectomy is based. Uterus is a child-bearing organ in females, situated in the pelvis between bladder and rectum. Though hollow, it is thick walled and firm, and can be palpated bimanually during a PV (per vaginum) examination. It is the organ which protects and provides nutrition to a fertilized ovum, enabling it to grow into a fully formed foetus. At the time of childbirth or parturition contractions of muscle in the wall of the organ result in expulsion of the foetus from the uterus. The uterus is pyriform in shape. It is about 7.5 cm long, 5 cm broad
and 2.5 cm thick. It weighs 30 to 40 grams. It is divisible into an upper expanded part called  the cervix. The junction of these two parts is marked by a circular constriction. The body forms the upper two-thirds of the organ, and the cervix forms the lower one third. Normally, the long axis of the uterus forms as angle of about 90 degrees with the long axis of the vagina. The angle is open forwards. The forward bending of the uterus relative to the vagina is called anteversion. The uterus is also slightly flexed on itself ; this is referred to as anteflexion. The angle of anteflexion is 125 degree. Roughly, the long axis of the uterus corresponds to the
axis of the pelvic inlet, and the axis of the vegina to the axis of the pelvic cavity and of the pelvic outlet.

Cervix of uterus
The cervix is the lower, cylindrical part of the uterus. It is less mobile than the body. It is about 2.5 cm long, and is slightly wider in the middle than at either end. The vaginal part of the cervix project into the anterior wall of the vagina. The space between it and the vaginal wall are called the vaginal fornices. The cervical canal opens into the vagina by an opening called the external os. In a nulliparous women, i.e. a women who has not borne children, the external os is small and circular. However, is multiparous women the external os is bounded by anterior and posterior lips,both of which are in contact with the posterior wall of the vagina.The cavical canal, i.e the cavity of the cervix is fusiform in shape. It communicates above with the cavity of the body of the uterus, through the internal os, and below with the vaginal cavity through the external os. The canal is flattened from before backwards so that it comes to have anterior and pasterior walls.These walls show mucosal folds which resemble the branches of a tree called the arbor vitac uteri. The folds in the anterior and posterior walls interlock with each other and close the canal. 

Role of individual supports
Pelvic Diaphragm : The pelvic diaphragm supports the pelvic viscere and resists any rise in the intra-abdominal pressure. The pubococcygeus part of the levator ani is partly inserted into the perineal body between  the vagina and the rectum. Some of these fibres also from a supporting sling and a sphincter for the vegina, and so indirectly for the uterus and the urinary bladder. If the pubococcygeus is torn during parturition, the support to the vegina is lost, and the latter tends to sink into the vestibule along with
the uterus, thus causing prolapse of the uterus. The efficacy of the levator ani as a support is also lost when the perineal muscles are torn. They normally fix the perineal body, and make it an anchor for the levator ani.
Perineal body : It is a fibromuscular node to which ten muscles are attached. It acts as an anchor for the pelvic diaphragm, and thus maintains the integrity of the pelvic floor. The muscles are two superficial transversus, two deep transversus perinei, two pubococcygeus part of levator ani, two bulbospongiosus and single sphincter ani externus and unstripped fibres of longitudinal muscle coat of the anal canal.

Ducts and ducts of gartner : In female, Mullerian  or paramesonephric duct predominates. This duct is situated lateral to mesonephric duct. It opens caudally into definitive urogenital sinus. Mullerian duct proliferates due to both presence of oestrogens and absence of testosterone and Mullerian inhibiting substance. Mullerian duct froms all four parts of fallopian tube. The distal part of the two ducts fuse to from the single uterovaginal canal which gives rise to uterus with its fundus, body and cervix parts. Wolffian
duct or mesonephric duct forms the trigone of urinary bladder as functional component. Duct of gartner is its vestigial component. Occasionally, the duct of the epoophoron is much larger than usual and is called the duct of Gartner. It can be traced first along the uterine tube, and then along the lateral margin of the uterus up to the level of the internal os. Further down it runs through the cervix and the lateral wall of the hymen. It represents the mesonephric duct. It may from a cyst in the anterior or lateral wall of the
vagina.