Exam 2 Lecture - Development of the Urogenital System Flashcards
Where is the urogenital ridge found?
in the dorsal part of the embryologic kidney
What are the 3 attempts to make the kidney called?
pronephros
mesonephros
metanephros
Where does the pronephric attempt occur?
most cranial attempt; in the neck
What does the pronephric attempt become?
the mesonephric duct
How does the mesonephros attempt of the kidney degrade?
once it reaches its maximum size, it degenerates from cranial to caudal
What does the mesonephros attempt become in the adult?
in the male, the caudal tubules and duct remain to form testicular channels, epididymis and ductus deferens
What is the metanephros?
the attempt of kidney creation that becomes the adult kidney
What structures create the adult kidney?
the metonephric diverticulum and the metonephrogenic mass
Where is the metonephric diverticulum located?
comes off of the mesonephric duct
What does the metonephric diverticulum differentiate the surrounding mesoderm into?
the metanephrogenic mass
What does the metanephrogenic mass give rise to?
the urine conducting part of the kidney (functional unit)
-ureter, renal pelvis, calyxes and collecting ducts
How are nephrons formed?
metanephric diverticulum causes areas within the metanephrogenic mass to differentiate into renal vesicles which will transition into metanephric tubules which creates nephrons
True or false: the animal cannot regrow a nephron
true
What cases variations in kidneys between species?
the differences between interactions of the metanephrogenic mesenchyme and the metanephric diverticulum
What does the bladder develop as an extension of?
the urachus and the cranial end of the urogenital sinus
What does the urogenital sinus become in the male?
pelvic urethra and penile urethra
What does the urogenital sinus become in the female?
pelvic urethra, vestibule and the caudal vagina
In early development, what does the mesonephric duct go into?
it goes directly into the bladder
What does the mesonephric duct become in the adult?
the ductus deferens in males
What does the metanephric diverticulum become in the adult?
the ureter
How does the mesonephric duct and the metanephric diverticulum become in the correct places that they should be in the adult?
the bladder grows dorsally so that the future ureter and ductus deferens empty into it separately, and then differential growth causes them to switch places so that the ureter empties into the bladder and the ductus deferens empties into the urethra
renal agenesis
lack of development
dysplasia
abnormal development of the kidney
hypoplasia
underdevelopment
ectopic kidneys
the kidney could be sitting in the pelvic cavity
patent urachus
when the urachus does not close right after birth and urine still flows through the allantoic cavity
ectopic ureter
not opening in the correct location
When is genetic sex determined?
at fertilization
What structures are present during indifferent development?
mesonephric duct and paramesonephric duct
What structure gives rise to male structures?
mesonephric duct
What structure gives rise to female structures?
paramesonephric duct
What suppresses the paramesonephric duct in males?
the mullerian inhibiting substance
What is the role of testosterone in males?
stimulate the mesonephric duct to create the ductus deferens and epididymis and stimulates the growth of the external genitalia
What is the role of estrogen in females?
- stimulate paramesonephric duct to create the uterine tube, uterus, cranial portion of the vagina
- stimulate the formation of external genitalia (labia, clitoris, and caudal portion of vagina)
How do germ cells migrate into the genital ridge?
-leave the yolk sac at about 100-300 cells and migrate into the embryo via the hind gut, through the mesentery, and into the genital ridge
What are the gondal cords formed by?
disintegrating mesonephric tubules
What do the mesonephric tubules become?
the seminiferous tubules, rete testis, efferent ductus
What does the mesonephric duct become?
ductus deferens, epididymis
In early development what is the function of the gubernaculum?
it just tethers the testicle in place
What type of tissue is the gubernaculum?
mesenchymal type tissue
How does the gubernaculum function?
hyaluronic acid brings water into the gubernaculum causing it to swell, then cells of the gubernaculum remove the acid causing it to shrink, bringing the testicle into the scrotum
What are the remnants of the gubernaculum?
the ligament of the tail of epididymis and the proper ligament of the testes
How are the follicles of the ovary created?
degenerating mesonephric tubules move into the area of development, forming the gonadal cords, the oocytes move into the gonadal cords, the oocytes begin to separate and create follicles
What does the paramesonephric duct give rise to?
uterine tube, uterine horn, body, cervix, part of the vagina
What does the urogenital sinus become?
part of the vagina, the vestibule
vagina and uterus duplex
no fusion between the paramesonephric ducts; found in marsupials
vagina simplex uterus duplex
single vagina with two uteri and two cervial canals; found in rabbits or rodents
uterus bicornis
two horned, fusion of the duct creates the body of the uterus; found in the horse
What does the genital tubercle become in the male?
glans penis, corpora cavernosa penis, corpus spongiosum penis
What does the genital tubercle become in the female
clitoris
What do the urogenital folds become in the male?
ventral aspect of the penis
What do the urogenital folds become in the female?
the labia of the vulva
What do the labioscrotal swellings become in the male?
scrotum
What do the labioscrotal swellings become in the female?
does not really develop into anything in domestic species
What is the anal genital distance?
the distance between the anus and where the tubercle ends up
When is the anal genital distance greater?
when the species is exposed to testosterone
Genital malformation: hypolasia
result of few or no germ cells
Genital malformation: cryptorchidism
retaining testicle on one or both sides
Genital malformation: stenosis of the ducts
abnormal fusion
Genital malformation: hypospadia
open urethra
Free martin
In dizygotic twins that share a blood supply; female is the most effected (suppression of paramesonephric duct derivatives)
