Embryology Flashcards
What does the urinary system develop from?
The intermediate mesoderm and the Cloaca
What does the intermediate mesoderm (nephrogenic cord/urogenital ridge) give rise to?
The kidneys and ureter
What does the cloaca give rise to?
The urinary bladder and urethra
What does the septum of the cloaca separate?
Recto-anal part from uro-genital part
What does the intermediate mesoderm form on either side of the aorta?
Urogenital ridge
What does the urogenital ridge develop into?
Three sets of tubular nephric structures:
- pronephros
- mesonephros
- metanephros
What duct persists while the tubules develop?
The duct into which the tubules drain
What does the duct into which the tubules drain grow out of?
Metanephros - mesoderm forms a cap around this duct and starts to form the excretory part of the kidney
What is the pronephros?
The cranial-most set of tubules, mostly regress
What is the mesonephros?
Located along the midsection of the embryo and develops into mesonephric tubules and mesonephric duct
Carry out some kidney function at first but then regress
What does the mesonephric duct persist into?
Persists and opens into the cloaca
What does the metanephros give rise to?
Definitive adult kidney
What does the metanephros develop from?
An outgrowth of the caudal mesonephric duct, the ureteric bud and from a condensation of nearby intermediate mesoderm (metanephric blastema)
What are the collecting tubules derivatives of?
The blastema
What is the collecting portion of the kidney derived from?
Ureteric bud - collecting duct, calyces, ureters
What embryological structures reciprocally induce each other to form kidney components?
Ureteric bud and metanephros
What is the ascent of the kidneys mainly due to?
The differential growth of the lower body inferiorly away from the kidneys
What vertebral level are the kidneys at?
T12-L3
In what direction does the hilum rotate?
From ventral to medial, to face the aorta from which it receives its blood supply
When does the ascent of the kidneys stop?
When there is contact with the adrenal glands
What happens to the vascular supply during the descent of the kidneys?
Segmental breakdown and reformation of vascular supply
What pole are the accessory renal arteries at?
Always at the inferior pole
What components of the urinary system form from the mesoderm, mesonephric duct and cloaca?
Mesoderm
- nephron
Mesonephric duct
- ureter
- renal pelvis
- calyces
- collecting duct
Cloaca
- urethra
- urinary bladder
What does the urorectal septum divides?
Divides the cloaca into the rectum and urogenital sinus
