Repro Development Flashcards
the ____ _____ appear in the 5th week on the medial aspect of the _____ which give rise to ____/______
they are indistinguishable until week __
the gonadal ridges appear in the 5th week on the medial aspect of the mesonephros which give rise to testes/ovaries
they are indistinguishable until week 7
the _____ forms the male gonads
the ____ forms the female gonads
the medulla forms the male gonads
the cortex forms the female gonads
describe what the Y chromosome encodes for
- Testis determining factor (TDF) encoded by the SRY gene on the short arm of Y chromosome which turns on testis development
what do the Sertoli cells produce?
Antimullerian hormone (AMH)
produced until puberty to suppress development of female ductal system
describe the 2 phases of testicular descent
- transabdominal
- “descent” of testis is a result of abdominal growth
- inguinal
- controlled by testosterone, guided into scrotum by gubernaculum
describe a congenital inguinal hernia
- if the connecting portion of the processes vaginalis does not obliterate, it leaves a patency in the inguinal canal where intestines may herniate through
describe a hydrocele
- the processes vaginalis contains a small amount of fluid before it obliterates
- if the fluid does not get reabsorbed = hydrocele
- identified by transilumination
describe cryptorchidism
- testes do not descend into the scrotum
- may be bi- or unilateral
- testes can be anywhere along the normal descent pathway
- usually found in the inguinal canal
- higher risk of germ cell tumors
describe ectopic testis
- after descending into the inguinal canal, it may become lodged in other areas
- there is descent
development of the _______ ______ lead to male genital ducts, which is stimulated by ______ from the _____ ______
development of the mesonephric ducts lead to male genital ducts, which is stimulated by testosterone from the Leydig cells
development of the _______ ______ lead to female genital ducts, unless suppressed by ______ from _____ _____ of developing teses
development of the paramesonephric ducts lead to female genital ducts, unless suppressed by AMH from Sertoli cells of developing teses
the _____ _____ thickens acquiring smooth muscle and becomes the ____ _____
the mesonephric duct thickens acquiring smooth muscle and becomes the ductus deferens
outgrowth from the caudal end of the ______ _____ gives rise to the ____ _____
outgrowth from the caudal end of the mesonephric ducts gives rise to the seminal vesicles
endodermal outgrowths from the _____ _____ differentiate into glandular tissue giving rise to ________
endodermal outgrowths from the prostatic urethra differentiate into glandular tissue giving rise to the prostate
bulbourethral glands are paired outgrowths from the ____ _____
bulbourethral glands are paired outgrowths from the spongy urethra
describe the uterovaginal primordium
gives rise to the superior portion of the vagina
describe the sinovaginal bulbs
fuse to form a vaginal plate which breaks down to form the vaginal canal
describe the formation of the hymen
formed by an invagination of the posterior wall of the urogenital sinus that separates the vaginal cavity from the urogenital sinus
describe the formation of the greater vestibular glands
they form as an outgrowth of the urogenital sinus in the lower 1/3 of the labia majora
describe how a double uterus forms
incomplete fusion of the paramesonephric ducts
describe the formation of a bicornate uterus
2 uterus cavities separated by a septum: incomplete fusion is only superior
describe the formation of a unicornate uterus
incomplete development of one of the paramesonephric ducts
describe how vaginal agenesis can occur
failure of the sinovaginal bulbs to develop and form the vaginal plate
absence of the vagina is usually accompanied by absence of the uterus since the development of the uterus induces the formation of the sinovaginal bulbs
describe vaginal atresia
incomplete canalization of the vaginal canal
describe the Canal of Nuck
in females, the round ligament passes through the inguinal canal and also carries with it a portion of the peritoneum
if the processes vaginalis remains patent, it is called the Canal of Nuck and is subject to hernias and hydrocele
describe the formation of the spongy (penile) urethra
the urethral folds fuse on the ventral surface of the penis to form the spongy (penile) urethra and the penile raphe (where surface ectoderm meets in the midline)
describe the formation of the corpus cavernosum and spongiosum
the corpus cavernosum and spongiosum develop from the mesenchyme in the phallus
describe the formation of the scrotum
the scrotum forms when the labioscrotal folds grow together and fuse
describe hypospadias
failure of urethral folds to fuse results in abnormal orifices on the ventral surface of the penis
the most common anomaly of the penis (1/300)
describe epispadias
- urethra opens on the dorsal surface of penis
- often associated with exstrophy of the bladder
the labia minora/vestibule of the vagina are formed both from __________ and ________ (phallic part)
the labia minora/vestibule of the vagina are formed both from ectoderm of the urethral folds and endoderm of the UG sinus (phallic part)
the _____ forms the penis in males and clitoris in females
genital tubercle
describe ovotesticular DSD (true hemaphroditism)
- rare and is a condition in which the gonads contain both ovarian and testicular tissue
- phenotype may be male or female
- chromosomal configuration usually 46, XX
describe 46, XY DSD
- males who produce inadequate levels of testosterone and AMH in utero
- external and internal genital organs vary in appearance due to variable degrees of development
describe 46, XX DSD
- females who have been exposed to excessive amounts of androgens in utero = adrenal hyperplasia
- causes masculinization of the external genitalia
- enlargement of clitoris, partial fusion of the labia majora, persistent urogenital sinus
describe androgen insensitivity syndrome (AIS)
- individuals who appear female but have 46, XY chromosome configuration
- results from cellular resistance to testosterone
- vagina ends blindly, rudimentary or absent uterus and uterine tubes
- testes present in the inguinal canal
- female breast development at puberty
- external genitalia is female or masculinized
describe 5-alpha reductase deficiency
- enzyme is necessary for conversion of testosterone to DHT
- DHT is essential for masculinization of external genitalia
- a deficiency in this enzyme leads to individuals that are genetically male 46, XY (with testes) appear female
- the testes don’t descend initially, but descend later
