Test 1 Flashcards
The timeframe for gonads to acquire their sex
determination
gonads do not acquire male or female characteristics until the seventh week of development.
The key to sexual dimorphism is found on the…
short arm of the Y chromosome, called the Sex-
Determining Region on Y (SRY), which is the testis-determining factor.
In its absence, female development is established
Primordial germ cells Start…
Mesenchymal or stem cells (future sperm or eggs)
that develop in the wall of the yolk sac near the
allantois that migrate along the mesentery of the
hindgut. This occurs at about the 3rd week of
embryologic development.
Homolog for the Scrotum?
labia majora
Homolog for Spongy urethra?
labia minora
Other names for paramesonephric ducts in a female.
also called Mullerian ducts
Other names for Mesonephric ducts in a male
also called Wolffian ducts
What does the Cranially part of paramesonephric become?
Opens up, funnel like structure. Will become fallopian tube fimbria/open ended fallopian tubes
What does the Caudally part of paramesonephric become?
Fuses together to form:
Uterine canal, Uterus, cervix, distal 1/3 of the vagina
The Mesonephric duct in male becomes?
o Epididymis o Vas deferens o Seminal vesicles o Ejaculatory duct o Connects to the primitive kidney
Primordial germ cells develop in the…
wall of the yolk sac near allantois
Primordial germ cells Migrate along the…
mesentery of the GI tract, called the hindgut
Primordial germ cells continue migration until they..
Reach the gonadal ridges and penetrate into the
primitive gonad
Before After, and during migration, Primordial germ cells penetrate into the primitive gonad, What happens?
The genital ridge proliferates and penetrates underlying mesenchyme forming a number of primitive sex cords, inserted itself down past the epithelium.
After the After Primordial germ penetrate the genital ridge they become immature eggs or sperm when they are surrounded by…
the sex cord cells
The sex cord cells surrounding the primordial germ cells will become…
the follicle cells
The lower part of the vagina is formed from
the…
posterior wall of the urogenital sinus
The anterior portion of the urogenital sinus forms…
urinary bladder and urethra.
Contact of the urogenital sinus by the paramesonephric ducts induces formation of the…
sinovaginal bulbs, a collection of endoderm from the wall of the urogenital sinus
Hymen formation occurs during
canalization
Congenital absence of the uterus is called…
agenesis
results from the failure of the
embryonic mullerian ducts to fuse properly and
the resulting median wall does not resorb.
Septate Vagina
The most common and most distal form of
vaginal outflow obstruction, occurring in 0.1%
of infant girls
Imperforate Hymen
o The presence of increased mucus secretions in the vagina secondary to maternal estrogen effects may result in Mucocolpos, appearing as a bulging hymenal membrane between the
labia
o The membrane may be white because of the trapped mucoid material and may lead to»>
Urinary tract infections, Bladder obstructions Due to urethral compression
Identifying Imperforate Hymen in the Neonate…
o Primary amenorrhea (no period/menstrual cycle) o Presence or absence of secondary sexual characteristics should be noted
o Lower abdominal or pelvic pain
o Urinary retention/constipation
o Diagnosis is made when a distended bluish hymenal membrane is observed in the vaginal
orifice/opening due to collected menstrual blood (hematocolpos)
Imperforate Hymen in an Adolescent
Refers to failure of the normal glandular
epithelium that lines the embryonic vagina to be
replaced by squamous epithelium during fetal
development
Vaginal Adenosis Due to DES
a synthetic estrogen, was used in the 1940’s and 1950’s for high-risk pregnancies (used to prevent abortion)
DES (morning after pill)
DES exposure anywhere from the 10th to about
the 18th week of gestation, arrests this
transformation process
At the 10th week of gestation, the upgrowth of
squamous epithelium derived from the urogenital
sinus replaces the glandular (mullerian)
epithelium lining the vagina and exocervix.
Manifests grossly as red, granular patches on the
vaginal mucosa which usually disappear as the
woman gets older.
Vaginal Adenosis Due to DES
A rare tumor of the vagina encountered
exclusively in women exposed to Diethly-
stilbesterol (DES).
Clear Cell Adenocarcinoma due to DES
Clear Cell Adenocarcinoma due to DES is Most common between ages…
17 and 22
Clear Cell Adenocarcinoma due to DES Develops most frequently on the…
anterior wall of the upper third of the vagina.
In more advanced stages of Clear Cell Adenocarcinoma due to DES they may spread by…
hematogenous or lymphatic routes.
A congenital anomaly of the female genital tract that
presents as a deformed, obstructed and nonfunctional
vagina that occurs in 1 in 4-5000 live female births
Vaginal Atresia