Severson: Normal and Abnormal Renal Development Flashcards
What gives rise to the UROGENITAL system (ridge)?
intermediate mesoderm
What gives rise to the URINARY system?
nephrogeneic cord/ridge
What gives rise to the GENITAL system?
gonadal/genital ridge
What are the developmental phases of the urinary system?
- Pronephric phase (FOREkidney)
- Mesonephric phase (MIDkidney)
- Metanephric phase (HINDkidney)
What gives rise to the PRONEPHRIC DUCT and grows caudally to open into the CLOACA?
Pronephros
What happens during the mesonephric phase?
PRNEPHRIC DUCT becomes the MESONEPHRIC (WOLFFIAN) DUCT
What gives rise to the MESONEPHRIC TUBULES?
mesonephros
What do the MESONEPHRIC TUBULES become?
efferent ducutles of hte male testis
What does the mesonephric duct become in the male?
ductus deferens
What does the mesonephric duct become in BOTH males and females?
ureteric bud
What does the ureteric bud grow into and eventually form?
The ureteric bud grows into the INTERMEDIATE MESODERM and initiates formation of the DEFINITIVE KIDNEY (aka the METANEPHROS)
What gives rise to the ureter, renal pelvis, major and minor calyces and collecting ducts?
ureteric bud
What does a nephron (metanephric tubule) consist of?
renal capsule, proximal tubule, loop of henle and distal tubule
What part of the mesoderm does the nephron arise form? What is it induced by?
INTERMEDIATE
arched collecting duct
What forms the glomerulus?
ENDOTHELIAL CELLS growing into the renal capsule
What do the uriniferous tubules consist of?
nephrons and collecting ducts (develop from different sources!)
Describe the location of the metanephric kidneys.
Initially located deep in the PELVIC REGION but migrate to the ABDOMINAL REGION
What causes the migration of the metanephric kidneys?
rapid growth of hte CAUDAL EMBRYO that gives the kidney an appearance of “ascent”
Why is it possible that more than one renal artery may be present in the metanephric kidney?
the adult kidney consists of five vascular lobes that are originally supplied by segmental vessels
What causes renal agenesis?
failure of URETERIC BUD and METANEPHRIC MESODERM to interact
Who does renal agenesis usually affect?
UNILATERAL on the LEFT
1/1000 M
What should be suspected in infants w/ SINGLE UMBILICAL ARTERY?
renal agenesis
Bilateral renal agenesis causes…
death
What causes a duplicated or branched ureter?
bifuraction of the ureteric bud
What is an ectopic ureter?
when the ureter enters a urogenital sinus at some site OTHER than the dorsolateral wall of hte urinary bladder
What causes supernumerary kidney?
division of the ureteric bud and its interactions with areas of hte metanephric mesoderm
What happens if the metanephric mesoderm is fused?
pelvic kidney fails to migrate from the pelvis
What is a crossed ectopic kidney?
when the kidney migrates to the opposite side and the two kidneys probably fuse
What is a horseshoe kidney?
when two kidneys fuse at their inferior poles and their migration from the pelvis is BLOCKED by the IMA
What causes multiple renal arteries?
segmental blood supply during development (multiple in 25% of people)
What is multicystic dysplastic kidney disease?
kidney cysts occur d/t abnormal dilations of hte nephrons (usually thin segments)
What divides the CLOACA into the rectum and urogenital sinu?
urorectal septum
What is the urogenital sinus continuous with?
allantois
What forms the urinary bladder nad is continuous w/ the allantois?
VESICLE PART of the urogenital sinus
What forms URACHUS and later becomes the MEDIAN UMBILICAL LIGAMENT
allantois
What part of the urogenital sinus becomes the BLADDER NECK and PROSTATIC URETHRA in the male and the ENTIRE URETHRA in the female?
pelvic part
What happens to the phallic/spongy part of the urogenital sinus?
it grows toward the genital tubercle
Where does the urorectal septum come in close contact w/ the cloacal membrane?
perineal body
What forms the trigone of the bladder?
The MESONEPHRIC DUCT is incorporated into the posterior wall of the developing urinary bladder resulting in the trigone of the bladder
Where does the epithelium of the bladder come from?
endoderm of the urogenital sinus
What is the origin of the proximal male urethra?
urogenital sinus
What is the origin of the distal male urethra?
ectodermal cord
What is the origin of the female urethra?
urogenital sinus
What is the CT and sm musc of the urinary bladder derived from?
splanchnic (visceral) mesenchyme
What is exstrophy of the bladder?
a bladder that opens onto the anterior abdominal wall
What causes exstrophy of the bladder?
failure of mesenchymal cells to migrate between ectoderm of the abdomen and cloaca during the 4th week>
anterior wall mesoderm degenerates>
exposes interior of the bladder
What causes megacystis?
the prescence of a POSTERIOR URETHRAL VALVE that blocks the flow of urine from the bladder
Where is megacystitis usually located?
in the area where the ejaculatory ducts enter the prostatic urethra
Blockage of urine outflow from megacystitis could lead to…
renal failure
pulmonary hypoplasia d/t uterine wall pressure on developing thorax
What is the origin of hte adrenocortical primordia?
CRANIAL part of the urogenital ridge
What does the adrenal cortex develop from?
mesothelial cells (mesoderm) from the posterior abdominal wall between the root of the dorsal mesentery and developing gonad
What is the largest part of the fetal adrenal gland that regresses during the first year after birth?
fetal cortex
What develops later in the developmental period from mesenchymal cells and replaces the fetal cortex?
permanent cortex
What is the origin of the adrenal medulla?
NCC
What innervates the chromaffin cells of the adrenal medulla? What do these nerves secrete?
PREganglionic nerve fibers that release EPI
