SM_179b: UG Development Flashcards
Describe the male genital anatomy
Male genital anatomy
Describe internal female genital anatomy
Internal female genital anatomy
Labia major is ____
Labia major is folds of the superficial body wall
Labia minor flanks the ____
Labia minor flanks the vestibule
(space with clitoris and openings of vagina and urethra)
Both sexes start with ____ primordia
Both sexes start with the same primordia
- Mesonephric duct -> male structures
- Paramesonephric duct -> female structures
____ becomes the male genital structures
Mesonephric duct becomes the male genital structures
____ becomes the female genital structures
Paramesonephric duct becomes the female genital structures
Describe the primordia of the urogenital system
Primordia of the urogenital system
- Intermediate mesoderm -> kidneys / gonads
- Splanchnopleure of the hindgut -> bladder / urethra
- Somatopleure -> genitals
Intermediate mesoderm becomes the ____
Intermediate mesoderm becomes the kidneys / gonads
Splanchnopleure of the hindgut becomes the ____
Splanchnopleure of the hindgut becomes the bladder / urethra
Somatopleure becomes the ____
Somatopleure becomes the genitals
With folding of the embryo, the intermediate mesoderm bulges into the peritoneal cavity and forms a ____ with ____ and ____
With folding of the embryo, the intermediate mesoderm bulges into the peritoneal cavity and forms a urogenital ridge with a nephrogenic cord and a gonadal ridge
Urogenital ridge consists of ____ and ____
Urogenital ridge consists of nephrogenic cord and gonadal ridge
(develop into kidneys and ovaries / testes)
Primordial germs cells migrate from the ____ into the ____
Primordial germs cells migrate from the hindgut into the gonadal ridges
Germ cells are surrounded by ____ that project into the ____
Germ cells are surrounded by epithelial sex cords that project into the primitive gonad
Paramesonephric (Mullerian) duct develops close to the ____
Paramesonephric (Mullerian) duct develops close to the mesonephric (Wolffian) duct
Mesonephric (Wolffian) duct and tubules develop as ____
Mesonephric (Wolffian) duct and tubules develop as condensations of intermediate mesoderm (nephrogenic cord)
Mesonephric (Wolffian) duct becomes the ____ and also ____ in the male
Mesonephric (Wolffian) duct becomes the fetal ureter and also changes its function from urinary to genital as it becomes the ductus deferens in the male
Paramesonephric (Mullerian) ducts will form ____ and join at their inferior ends to form the ____ and ____
Paramesonephric (Mullerian) ducts will form the uterine tubes and join at their inferior ends to form the uterus and upper vagina
Nephrogenic cord forms three sequential kidneys: ____, ____, and ____
Nephrogenic cord forms three sequential kidneys:
- Pronephros
- Mesonephros
- Metanephros
First functioning kidney is the ____
First functioning kidney is the mesonephros
____ joins the ____ of the first functioning kidney and drains into the cloaca
Mesonephric duct joins the mesonephric tubules of the first functioning kidney and drains into the cloaca
____ duct is also called the Wolffian duct and is the first (and temporary ureter)
Mesonephric duct is also called the Wolffian duct and is the first (and temporary ureter)
Metanephric diverticulum is also called the ____ and originates from the mesonephric duct
Metanephric diverticulum is also called the ureteric bud and originates from the mesonephric duct
Primordia of the metanephros (permanent kidney) are ____ and ____
Primordia of the metanephros (permanent kidney) are
- Ureteric bud
- Metanephric mass of intermediate mesoderm
Urinary collecting duct and transport system come from the two metanephric primordia: ____ and ____
Urinary collecting duct and transport system come from the two metanephric primordia:
- Metanephric mesoderm gives rise to kidney nephrons
- Ureteric buds give rise to ureters, renal pelvis, calyces, and collecting tubules in the pyramids
____ gives rise to the kidney nephrons
Metanephric mesoderm gives rise to the kidney nephrons
____ gives rise to the ureters, renal pelvis, calcyes, and collecting tubules in the pyramids
Ureteric buds gives rise to the ureters, renal pelvis, calcyes, and collecting tubules in the pyramids
As the kidney ascends, ____
As the kidney ascends, the mesonephros degenerates
As the kidney ascends, ____ hook up to it and may persist as ____
As the kidney ascends, sequential arteries hook up to it and may persist as multiple renal arteries
____ is a fusion of the ureteric buds that hook around the inferior mesenteric artery as they ascend
Horseshoe kidney is a fusion of the ureteric buds that hook around the inferior mesenteric artery as they ascend
Horseshoe kidney is ____
Horseshoe kidney is a fusion of the ureteric buds that hook around the inferior mesenteric artery as they ascend
Describe other anomalies of urogenital tract
Other anomalies of urogenital tract
- Mutliple buds resulting in multiple kidneys, renal pelvises, or ureters and failure of buds to ascend
____ divides the cloaca into a rectum and urogenital septum with bladder, pelvic, and phallic parts
Urorectal septum divides the cloaca into a rectum and urogenital septum with bladder, pelvic, and phallic parts
Urorectal septum divides the cloaca into ____, ____, and ____ parts
Urorectal septum divides the cloaca into a rectum and urogenital sinus with bladder, pelvic, and phallic parts
Improper division of the cloacas results in ____
Improper division of the cloacas results in fistulas
(also imperforate anus)
Allantois usually becomes a ____ called the ____
Allantois usually becomes a fibrous cord called the urachus
- Like any other embryonic tube, it may persist as a cyst, sinus, or fistula
Exstrophy of the bladder / cloaca involves ____ and ____, exposing ____
Exstrophy of the bladder / cloaca involves failure of mesoderm migration into the cloacal membrane / ventral abdominal wall ad breakdown of the ectoderm / anterior bladder / cloacal wall, exposing posterior mucosa
8-weeks is called the ____ stage of sexual development because both sexes have ____
8-weeks is called the indifferent stage of sexual development because both sexes have identical primordia
Gonadal development occurs from the ____
Gonadal development occurs from the gonadal ridge
- Epithelial sex cords project into the gonads in two waves
In testis development, primary sex cords become ____
In testis development, primary sex cords become seminiferous tubules
(sertoli cells)
In ovary development, secondary sex cords become ____
In ovary development, secondary sex cords become ovarian follicles
(granulosa cells)
External genital development involves a ____ and ____
External genital development involves a tubercle and two folds
Labioscrotal folds flank ____ and ____
Labioscrotal folds flank UG folds and genital tubercle
Lower UG sinus becomes the ____ in the female and UG folds the ____
Lower UG sinus becomes the vestibule in the female and UG folds the labia minora
UG sinus in the male forms most of the ____
UG sinus in the male forms most of the penile urethra
Clitoris is homologous to the ____
Clitoris is homologous to the penis
Labia majora are equivalent to the ____
Labia majora are equivalent to the scrotum
While most of the penile urethra comes from a ventral fusion of the urogenital sinus, the ____ in the glans comes from an ____
While most of the penile urethra comes from a ventral fusion of the urogenital sinus, the navicular fossa in the glans comes from an ectodermal invagination from the end of the penis
Two primordia of the male urethra must ____
Two primordia of the male urethra must fuse
Failure of the urogenital folds to fuse leads to ____
Failure of the urogenital folds to fuse leads to hypospadius
Summarize female primordia
Female primordia
Failure of the paramesonephric ducts to fuse with each other or the urogenital sinus leads to ____
Failure of the paramesonephric ducts to fuse with each other or the urogenital sinus leads to agenesis
Summarize male primordia
Mesonephric is ____, while paramesonephric is ____
Mesonephric is male, while paramesonephric is paramesonephric
- Complicating factors: three successive kidneys, mesonephros is huge, mesonephros changes its function from urinary to genital in the male (or at least its duct system)
Summarize urogenital development
Urogenital development summary
- Early UG development: intermediate mesoderm
- Nephrogenic ridge, genital ridge, cloaca (rectum, UG sinus - bladder, urethra, vestibule)
- Kidneys: pronephros, mesonephros, metanephros
- Internal genital organs: gonads, mesonephric ducts, paramesonephric ducts
- Gonads (from genital ridge): primary and secondary sex cords
- External genital organs: genital tubercle, urogenital folds and sinus, labioscrotal folds
