urogenital development

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footcramp

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apparently i'm either a ***** or i blew off embryology, or maybe both, but i can't understand how the mesonephric duct is forms the collecting duct of the kidney AND the internal male structures. well, i understand what happens separately, but i don't know how they are connected when they are fully developed.

ok so the collecting duct goes down and connects to the bladder. that part understood.

and the ductus deferens connects to the urethra under the bladder. i think that's right.

so my question is, does the bladder form from the mesonephric duct too? if not, how are the collecting duct and vas deferens connected originally?

also, in women, the mesonephric duct is supposed to degenerate. does this happen AFTER the collecting duct is formed? does this mean that the bottom half of the mesonephric duct degenerates while the top half which forms the collecting duct is intact?

i'm very confused. thanks for any help.
 
footcramp said:
apparently i'm either a ***** or i blew off embryology, or maybe both, but i can't understand how the mesonephric duct is forms the collecting duct of the kidney AND the internal male structures. well, i understand what happens separately, but i don't know how they are connected when they are fully developed.

ok so the collecting duct goes down and connects to the bladder. that part understood.

and the ductus deferens connects to the urethra under the bladder. i think that's right.

so my question is, does the bladder form from the mesonephric duct too? if not, how are the collecting duct and vas deferens connected originally?

also, in women, the mesonephric duct is supposed to degenerate. does this happen AFTER the collecting duct is formed? does this mean that the bottom half of the mesonephric duct degenerates while the top half which forms the collecting duct is intact?

i'm very confused. thanks for any help.

This just further reminds me of how i HATE embryo! sorry no help just wanted to express that!
 
Copied from my notes.....

Cloaca divisions:
Ventral part becomes urogenital sinus and eventually bladder
Posterior part becomes distal end of digestive system – rectum and anus
The bladder incorporates the inferior end of the mesonephric duct into its wall and eventually the mesonephric diverticulum develops its own opening into the urogenital sinus.
The metanephric duct (from the kidney – metanephros is last stage, remember?) becomes the ureter (so this makes sense since the duct would be coming from the kidney)
Caudal end of embryo grows down and away relative to location of kidneys – so it appears as if the kidneys ascend from their initial place in the pelvis (behind the bladder)…….what happens is testes are tethered and are pulled down by this growth, but the kidneys are not tethered

In the male, you need a duct system to transfer sperm down through a duct to the urethra where it continues to pass through the penis. In the female, they don’t need that—they ovulate into uterine tube.
In males, the mesonephric duct becomes the vas deferens. The ejaculatory duct opens into the prostatic portion of the urethra instead of the bladder. It’s used to make the epidydimis and vas deferens
In females the ejaculatory duct degenerates

Hope that helps. Also, get High Yield Embryo - very readable and very succinct.
 
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