Migrates ventrally to project into the coelomic cavity as the Urogenital Ridge
Intermediate Mesoderm
What does the urogenital ridge start to differentiate into during weeks 4-5?
Medial projection (gential ridge) and lateral projection (nephrogenic cord)
Superficial portion of the evaginated genital ridge
Primary sex cords
Deep portion of the evaginated genital ridges
Rete cords
What does the peripheral portion of the gondal mesoderm begins to form what?
Tunica albuginea
Originally forms in the epiblast then migrates tinto the caudal surface of the yolk sac
Primordial Germ Cells
Expression of this gene activates one regulatory network that promotes testicular development and a second regulatory network that inhibits ovarian development
SRY gene
The product of the SRY gene
Testis-Determining Factor
What is formed when the primordial germ cells invade the primary sex cords?
Testicular Cords
When rete cords expland, linking the testicular cords and the mesonephric tubules
Rete Testis
When the portion of the mesonephric tubules contacted by the rete testis will differentiate into what?
Efferent Tubule
Mesenchyme between adjacent testicular cords differentiate into what?
Leydig cells
Epithelial cells of the testicular cords will differentiate into what?
Sertoli (sustentacular) cells
What is the second series of epithelial invaginations that are formed in the absence in the SRY gene
Cortical cords
What do the cortical cords break down into?
Primary germ cells (oogonium) and cortical epithelial cells (follicular cells)
Combination of oogonium and cortical epithelial cells
Primordial Follicle
A connective tissue tether that is supported by the inferior pole of the gonads
Gubernaculum
What does the fusion of the gubernaculum and the lateral surface of the uterus cause?
The splitting of the gubernaculum into the ovarian ligament and the round ligament of the uterus
47 XXY abnormality
Klinefelter syndrome
45 X? abnormality
Turner syndrome
Gonads develop both testicular and ovarian tissues and are non-functional (aka ovotestis)
Ovotesticular DSD
Nephric tubules merge with the pronephric duct to form what?
Mesonephric Duct (Wolffian Duct)
Parallels the mesonephric ducts
Paramesomephric Duct (Mullerian Duct)
The portion of the mesonephric duct located between the cloaca/bladder and ureter
Common Nephric Duct
The mesonephric duct regresses to what in females?
Epoophoron, Paroophoron, Gartner’s duct
Formed by the proximal end of the Mullerian duct
Testicular Appendix
Formed by the distal end of the Mullerian duct
Prostatic Utricle
Produces apoptosis of the paramesonephric duct
Anti-mullerian factor hormonone
What pushes the cloaco from the cranial surface and and continues until reaching the cloacel membrane
Urorectal Septum
Internal folds on the lateral surfaces of the cloaca
Lateral or Rathke folds
What is formed by the urorectal septum?
Dorsal rectum and the ventral urogenital sinus
Point of contact between the urorectal septum and the cloacal membrane
Perineal body
Formed by the connective tissue of the allantois
Urachus
Remants of the urachus between the urogenital sinus and umbilical cord
Median Umbilical Ligament
Largest portion of the urogenital sinus and will form the urinary bladder
Vesical
What does the pelivc portion of the urogenital sinus form?
Membranous urethra, prostatic urethra, (males). Urethra, distal portion of the vagina (females).
Definitive portion of the urogenital sinus forms what?
Penile urethra (males), Labia minora and vestibule (females)
Uterovaginal primordium persists as what in males?
Prostatic Utricle or Utriculus
On either side of the utricle
Ejaculatory ducts
In females, the urogenital sinus gives rise to what paired outgrowths
Sinovaginal bulbs
What do the fused sinovaginal bulbs form?
Vaginal plate
Contact point between the sinovaginal bulb and the urogential sinus persists as what?
Hymen
Mesenchyme surrounding the cloacal membrane proliferates in week 4 to form what?
Indifferent external genitalia
Characterizes the indifferent external genitalia with a ventral midline elevation
Genital Tubercle
two ridges that extend dorsally for the genital tubercles
Urethral folds
The depression between the paired urethral folds
Urethral Groove
Forms the floor of the urethral groove
Urethral plate
Second, larger pair of folds on the lateral surface of the urethral folds
Labioscrotal swelling
Urethral folds will fuse in the midline ro form what?
Penile (spongy) urethra
Gential tubercle elongates to form what?
Penis
Labioscrotal swelling expand dorsally and fuse at the midline to form what?
Scrotum
Formed by the ectodermal cord fusing with the distal end of the spongy urethral
Extrenal urethra meatus
When the spongy urethra opens to the ventral surface
Hypospadias
Spongy urethra opens to the dorsal surface of the penis
Epispadis
In females, the genital tubercles elongates to form what?
Clitoris
In females, urethral folds remained paired forming what?
Labia minora
Labia minora define the lateral walls of what?
vestibule
Labioscrotal swellings expand laterally for form what in females?
Labia majora
Genetic males with normally-developed testes, but the leydig and sertoli cells are non-secretory
Male Pseuo-intersexuality
Genetic males with normally-developed testes which secrete normal levels of androgens, but the mutations block the membrane receptor for androgens genital ducts are lacking and the external genitalia differentiate as female
Complete androgen insensitivity
Autosomal recessive disorder involving excessive steriodogenesis, producing mixed genital ducts and external male genitial
Congential adrenal hyperplasia