Embryology Flashcards
Where does the first part of the kidney (prenephros) first develop?
Cervical region
What are the three kidney systems?
Pronephros
Mesonephros
Metanephros
Why is the pronephros important?
The duct extends from the cervical region to the cloaca and drives the development of the next developmental stage.
It also provides useful data on kidney development.
What is the urogenital ridge?
Region of intermediate mesoderm giving rise to both embryonic kidney and gonads
Where do the mesonephric tubules develop?
Caudal to the pronephric region
Why can’t the mesonephros be used in life?
Because they don’t have a water conservation function
Why is the mesonephros important?
Its duct has an important role in the development of the reproductive system in male.
It also sprouts the URETERIC BUD which induces the development of the definitive kidney.
Why is the ureteric bud important?
Produces signals to induce the development of the true kidney, the metanephros in the undifferenced intermediate mesoderm caudal to the mesonephros.
How does the ureteric bud help develop the kidney?
Diagram Collecting system (collecting duct) from ureteric bud and excretory system from intermediate mesoderm under the influence of the ureteric bud.
Does the embryonic kidney move?
Yes!
It is at first sitting in what appears to be the pelvic cavity.
This means there is an apparent caudal to cranial shiftcrossing the arterial fork
formed by vessels returning blood from the fetus to the placenta.
The kidney then reaches its true position in the lumbar region.
How does the blood supply to kidney change?
As kidney ascends, there is a new blood supply that is formed that links directly to the abdominal aorta.
This means that people could be left with remnants of the previous blood supply.
What is renal angenesis?
When the bud fails to interact with the intermediate mesoderm.
What could happen if migration goes wrong?
Pelvic kidney as kidney
stays in starting position.
Horseshoes kidney as moving up into abdomen, caudal poles get close to each other and fuse. This means it stops at first unpaired branch of the abdominal aorta.
What occurs if the ureteric bud splits partially or completely?
Ectopic urethral orifice.
Eg opening into urethra or into vagina - causes incontinence as no urethral sphincter to maintain bladder.
How is the urogenital sinus created?
From the hindgut by urorectal septum.
UGS is continuous with the umbilicus which, at this point, is called the urachus
The umbilicus then closes and becomes the medial umbilical ligament.
