Embryology Flashcards
from what layer does the urogenital system develop speicifcally?
mesoderm layer - intermediate mesoderm
In the lateral folding of embryo picture shown, label all the parts with arrows in order of top to bottom
- Neural tube
- Paraxial mesoderm –> somites
- Intermediate plate mesoderm –> UG system
- Endoderm
- Ectoderm
- Lateral plate mesoderm: somatic
- Lateral plate mesoderm: splanchnic
- Intra-embryonic coelom
where does the intermediate mesoderm lie?
on the posterior abdominal wall
- whereabouts is the amniotic cavity
- whereabouts is the yolk sac - what lines it?
- what does ectoderm form?
- amniotic cavity - layer outisde ectoderm
- yolk sac is lined by endoderm (sits inside endoderm)
- ectoderm forms skin coverings of whole of embryo, neural tube & notochord
in this midsagittal section of the head and tail fold, what do the light blue and black lines represent?
- light blue= boundary of amniotic cavity
- black= chorion
in this last picture in this diagram, the head and tail fold join to form the ………. that later goes on to form the ………..
body stalk that later goes on to form umbilical cord
what is the Allantois and what is it connected to?
it is an outpouching of the endoderm at the hindgut that extends into the body stalk, and is connected to the cloaca
What is the cloaca?
is a single posterior opening for a bird’s digestive, urinary and reproductive tracts & is used to expel faeces and lay eggs
What happens to the cloaca in humans?
- divides into 2 different tubes:
- Urogenital sinus anteriorly
- Rectum posteriorly
wht divides the UG sinus and rectum?
the urorectal septum
what does the UG sinus go on to form?
urinary bladder and urethra
after the development of the urinary bladder and urethra, from cloaca and allantois, what happens?
Intermediate mesoderm develops into the rudimentary pronephros in neck (week 4), Mesonephros in trunk region (week 5 to 9) with a duct and tubules
where does the mesonephric duct drain into?
UG sinus
- what is the 3rd set of kidneys called
- what region does it develop from
- what does it consist of?
- metanephros
- develops from pelvic region
- consists of ureteric bud & metanephric mesoderm
where does ureteric bud grow out of?
caudal end of mesonephric duct
what does ureteric bud develop into?
kidneys and ureters - branches to form ureters, renal pelvis, calyces and collecting tubules
what does the mesonephric duct go on to form?
vas deferens
in females, what does mesonephros become?
ovary
how does the nephron develop overall?
the ureteric bud and metanephric mesoderm reciprocally induce one another
what happens to the kidneys once they have developed, but are in pelvic area?
- they rise due to differential growth of abdominopelvic structures
- aquire new blood vessels & hilum rotates to face medially
- Stops when come in contact with adrenal glands
