Embryology Flashcards
What does the Urinary System develop from?
The intermediate Mesenchyme
What are the overlapping kidney systems which develop in the embryo?
The pronephroi, the mesonphroi and the metanophroi
When does the pronephroi form?
Early in the 4th week
When does the mesonephroi form?
Late in the 4th week
What is the metanophroi?
The primordial of the permanent kidneys
When does the metanophroi begin to develop?
In the 5th week
When does the metanophroi become functional?
In the 9th week
What are the sources from which the kidneys develop?
The uretic bud (metanephric diverticulum) and the metanephrogenic blastema (metanephric mass or mesenchyme)
What is the positional change of the kidneys?
They move from close to each other in the pelvis in the fetal position to the abdomen in the adult position
How does the hilum of the kidney move during development?
It rotates 90 degrees medially
What is Renal Agenesis?
When the Ureteric buds do not develop or the primordia of the ureters degenerate
What is it called when the ureteric buds do not develop?
Renal Agenesis
What is the result of Renal Agenesis?
Failure of kidney development since no nephrons are induced by the collecting tubules to develop
What is the result of unilateral renal agenesis?
One of the kidneys does not develop so the other kidney overdevelops to compensate
What is a malrotated kidney?
The kidneys fail to rotate and maintain their embryonic position
What are ectopic kidneys?
One or both kidneys may be in abnormal positions as the fail to ascend from the embryonic position
What is a horseshoe kidney?
When the poles of the kidney are fused
What are the parts of the urogenital sinus?
- The Vesical part
- The Pelvic part
- The Phallic part
What does the cortex of the suprarenal glands develop from?
The mesenchyme
What does the medulla of the suprarenal glands develop from?
The neural crest cells
What is the function of the fetal cortex of the suprarenal glands?
It produces steroid precursors that are used by the placenta for the synthesis of estrogen
What does the Ureteric Bud form?
The Ureter, the Renal Pelvis, the Major and Minor Calyces and the collecting tubules
