vicent tibaijuka
JF-Expert Member
- Mar 22, 2012
- 268
- 57
kwanzalazima tuelezee bikrani nn! bikra ni kiwambo chembamba cha mviringo chenye kitobo katikati ambacho au kwa maelezo zaidi soma hapa chini,:-
The hymen is a membrane that surrounds orpartially covers the external vaginal opening.It forms part of the vulva, or externalgenitalia. The size of the hymenal opening may or may not increase with age.Although an often practiced method, it is not possible to confirm that a girlor woman is a virgin by examining herhymen. The hymen does not wear away with age and is usually present from thetime of birth until death. By the time a girl reaches puberty the hymen isfluffy, estrogenized, and elastic.
In children, although a common appearance of the hymenis crescent-shaped, manyvariations are possible After a woman gives birth, she may haveremnants of the hymen, called carunculaemyrtiformes, but the hymen will never be completely absent.
Development
The genital tract develops during embryogenesis,from the third week of gestation to the second trimester, and the hymen isformed following the vagina.
At week seven, the urorectal septum forms andseparates the rectum from the urogenital sinus.
At week nine, the müllerian ducts move downwards toreach the urogenital sinus, forming the uterovaginal canal and inserting intothe urogenital sinus.
At week 12, the müllerian ducts fuse to create aprimitive uterovaginal canal called unaleria
At month 5, the vaginal canalization is complete andthe fetal hymen is formed from the proliferation of the sinovaginal bulbs(where müllerian ducts meet the urogenital sinus), and becomes perforate beforeor shortly after birth.
In newborn babies, still under the influence of themother's hormones, the hymen isthick, pale pink, and redundant (folds in on itself and may protrude). For thefirst two to four years of life, the infant produces hormones that continuethis effect. Their hymenal opening tends to be annular (circumferential).
Resorption
Past neonatal stage, the diameter of the hymenalopening (measured within the hymenal ring) has been proposed to beapproximately 1 mm for each year of age. In children, to make this measurement, adoctor may place a Foleycatheter into the vagina and inflate the balloon behind the hymen tostretch the hymenal margin and allow for a better examination. In the normalcourse of life, the hymenal opening can also be enlarged by tampon or menstrual cup use, pelvicexaminations with a speculum,regular physical activity or sexual intercourse. Once a girl reaches puberty,the hymen becomes elastic and estrogenized and it is not possible to determinewhether a woman is a virgin or uses tampons by examining her hymen. In onesurvey, only 43% of women reported bleeding the first time they hadintercourse, indicating that the hymens of a majority of women are sufficientlyopened.
The hymen is most apparent in young girls: At thistime, their hymen is thin and less likely to be redundant, that is to protrude or fold over on itself. Ininstances of suspected child abuse, nurses and doctors use the clock face system as a reference todesignate location of a specific finding on the vulva. The 12 o'clock positionis below the urethra, and 6 o'clock istowards the anus, with the patientlying on her back.
Infant's hymens tend to be redundant (sleeve-like,folding in on itself),due to the estrogenization from the mother and may bering-shaped. By the time a girl reaches school age, this hormonal influence hasceased, and the hymen becomes thin, smooth, delicate, and nearly translucent. It is alsovery sensitive to touch; a physician who must swab the area should avoid thehymen and swab the outer vulvalvestibule instead.
Prepubescent girls' hymenal openings come in manyshapes, depending on hormonal and activity level, the most common beingcrescentic (posterior rim): no tissue at the 12 o'clock position;crescent-shaped band of tissue from 12 to 1011 o'clock, at its widest around6 o'clock. From puberty onwards, depending on estrogen and activitylevels, the hymenal tissue may be thicker, and the opening is often fimbriatedor erratically shaped. In cases of suspected rape or childsexual abuse, a detailed examination of the anus, genitals, andhymen may be performed, but the condition of the hymen alone is ofteninconclusive. In younger children, a torn hymen will typically heal. Inadolescents, the hymen is estrogenized, thickened, and elastic.
Anatomic anomalies
Various types of hymen
Anomalies of the female reproductive tract can resultfrom agenesisor hypoplasia, canalization defects, lateral fusion and failure of resorption,resulting in various complications.
In some cultures, an intact hymen is highly valued atmarriage mainly to show virginity.Some women undergo hymenoplasty, a restoration of their hymen for this reason.
Womb fury
In the sixteenth and seventeenth centuries, medicalresearchers used the presence of the hymen, or lack thereof, as foundingevidence of physical diseases such as "womb-fury" (hysteria). If not cured,womb-fury would, according to these early doctors, result in death.
In other animals
Due to similar reproductive system development, manymammals, including chimpanzees, elephants, manatees, whales, and horses retainhymens.
The hymen is a membrane that surrounds orpartially covers the external vaginal opening.It forms part of the vulva, or externalgenitalia. The size of the hymenal opening may or may not increase with age.Although an often practiced method, it is not possible to confirm that a girlor woman is a virgin by examining herhymen. The hymen does not wear away with age and is usually present from thetime of birth until death. By the time a girl reaches puberty the hymen isfluffy, estrogenized, and elastic.
In children, although a common appearance of the hymenis crescent-shaped, manyvariations are possible After a woman gives birth, she may haveremnants of the hymen, called carunculaemyrtiformes, but the hymen will never be completely absent.
The genital tract develops during embryogenesis,from the third week of gestation to the second trimester, and the hymen isformed following the vagina.
At week seven, the urorectal septum forms andseparates the rectum from the urogenital sinus.
At week nine, the müllerian ducts move downwards toreach the urogenital sinus, forming the uterovaginal canal and inserting intothe urogenital sinus.
At week 12, the müllerian ducts fuse to create aprimitive uterovaginal canal called unaleria
At month 5, the vaginal canalization is complete andthe fetal hymen is formed from the proliferation of the sinovaginal bulbs(where müllerian ducts meet the urogenital sinus), and becomes perforate beforeor shortly after birth.
In newborn babies, still under the influence of themother's hormones, the hymen isthick, pale pink, and redundant (folds in on itself and may protrude). For thefirst two to four years of life, the infant produces hormones that continuethis effect. Their hymenal opening tends to be annular (circumferential).
Resorption
Past neonatal stage, the diameter of the hymenalopening (measured within the hymenal ring) has been proposed to beapproximately 1 mm for each year of age. In children, to make this measurement, adoctor may place a Foleycatheter into the vagina and inflate the balloon behind the hymen tostretch the hymenal margin and allow for a better examination. In the normalcourse of life, the hymenal opening can also be enlarged by tampon or menstrual cup use, pelvicexaminations with a speculum,regular physical activity or sexual intercourse. Once a girl reaches puberty,the hymen becomes elastic and estrogenized and it is not possible to determinewhether a woman is a virgin or uses tampons by examining her hymen. In onesurvey, only 43% of women reported bleeding the first time they hadintercourse, indicating that the hymens of a majority of women are sufficientlyopened.
The hymen is most apparent in young girls: At thistime, their hymen is thin and less likely to be redundant, that is to protrude or fold over on itself. Ininstances of suspected child abuse, nurses and doctors use the clock face system as a reference todesignate location of a specific finding on the vulva. The 12 o'clock positionis below the urethra, and 6 o'clock istowards the anus, with the patientlying on her back.
Infant's hymens tend to be redundant (sleeve-like,folding in on itself),due to the estrogenization from the mother and may bering-shaped. By the time a girl reaches school age, this hormonal influence hasceased, and the hymen becomes thin, smooth, delicate, and nearly translucent. It is alsovery sensitive to touch; a physician who must swab the area should avoid thehymen and swab the outer vulvalvestibule instead.
Prepubescent girls' hymenal openings come in manyshapes, depending on hormonal and activity level, the most common beingcrescentic (posterior rim): no tissue at the 12 o'clock position;crescent-shaped band of tissue from 12 to 1011 o'clock, at its widest around6 o'clock. From puberty onwards, depending on estrogen and activitylevels, the hymenal tissue may be thicker, and the opening is often fimbriatedor erratically shaped. In cases of suspected rape or childsexual abuse, a detailed examination of the anus, genitals, andhymen may be performed, but the condition of the hymen alone is ofteninconclusive. In younger children, a torn hymen will typically heal. Inadolescents, the hymen is estrogenized, thickened, and elastic.
Anatomic anomalies
Various types of hymen
Anomalies of the female reproductive tract can resultfrom agenesisor hypoplasia, canalization defects, lateral fusion and failure of resorption,resulting in various complications.
- Imperforate: hymenal opening nonexistent; will require minor surgery if it has not corrected itself by puberty to allow menstrual fluids to escape.
- Cribriform, or microperforate: sometimes confused for imperforate, the hymenal opening appears to be nonexistent, but has, under close examination, small openings.
- Septate: the hymenal opening has one or more bands of tissue extending across the opening.
In some cultures, an intact hymen is highly valued atmarriage mainly to show virginity.Some women undergo hymenoplasty, a restoration of their hymen for this reason.
Womb fury
In the sixteenth and seventeenth centuries, medicalresearchers used the presence of the hymen, or lack thereof, as foundingevidence of physical diseases such as "womb-fury" (hysteria). If not cured,womb-fury would, according to these early doctors, result in death.
In other animals
Due to similar reproductive system development, manymammals, including chimpanzees, elephants, manatees, whales, and horses retainhymens.
