TBL 20 Flashcards
What else are retroperitoneal organs, like the kidneys?
the adrenal (suprarenal) glands and ureters
What is each kidney surrounded by?
Perinephric fat that extends into its hollow center called the renal sinus
What encloses the perinephric fat and the kidney, adrenal glands and ureters?
Kidney and perinephric fat are enclosed by the fibrous renal fascia that is prolonged along the ureter as the periureteric fascia
What is the renal fascia continuous with?
It is continuous superiorly with the diaphragmatic fascia.
What separates the adrenal gland and kidneys?
fascial septum
What is the primary fascial attachment of the adrenal glands?
It is to the diaphragmatic fascia and NOT the renal fascia.
Where do the kidneys lie in the body?
Due to the liver:
Right kidney: deep to 12th rib
Left kidney: deep to the 11 rib
When can vertical movement of the kidneys occur?
during respiration
changing from supine to erect positions
Why is only the right kidney palpable in lean adults and when can the left kidney be palpated?
Palpation of the right kidney is possible because it is 1-2cm inferior to the left one. The left kidney is usually not palpable unless it is enlarged or a retroperitoneal mass has displaced it inferiorly.
Why can kidneys descend when the body is erect? Do the adrenal glands descend with the kidneys?
Because the layers of the renal fascia do not fuse firmly inferiorly to offer resistance, abnormally mobile kidneys may descend more than the normal 3cm when the body is erect.
When the kidneys descend, the adrenal glands remain in place because they lie in a separate fascial compartment and are firmly attached to the diaphragm.
What is the renal pelvis?
It is the funnel shaped superior end of the ureter that lies posterior to the renal vessels at the hilium of the kidney.
What do long ureters (25-30 cm) pass over to enter the pelvis?
bifurcation of the common iliac arteries
What are three potential sites where kidney stones (aka calculli) can obstruct the ureters?
1) uteropelvic junction
2) crossing the external iliac artery and/or pelvic brim
3) ureter traverses the bladder wall
Where do renal arteries arise from? What supplies the adrenal glands?
Renal arteries arise from teh abdominal aorta is close proximity to the SMA.
Adrenal glands are supplied by small branches arising from the renal arteries and the aorta.
Where do lymph from the kidneys, ureters and adrenal glands drain into?
lumbar lymph nodes positioned bilaterally along the abdominal aorta
Where do fibers of the lesser and least splanchnic nerves synapse?
aorticorenal ganglion
What forms plexuses that surround the renal arteries?
postsynaptic sympathetic fibers
branches of the vagus nerves
What does sympathetic mediated vasoconstriction contribute to in the kidneys/ adrenal gland?
regulation of blood flow to the kidneys
fibers of the least splanchnic nerve directly enter the medulla of the adrenal glands to synapse with modified sympathetic neurons
Why are varicoceles (varicosities of the pampniform venous plexus) more common on the left side?
Venous blood from the left testicular vein must drain upward to the left renal vein before emptying into the IVC. There is a chance of backflow due to gravity, resulting in left-sided testicular varicoceles.
How is intermittent pain from nephroptosis relieved?
Symptoms of intermittent pain in the renal region , relieved by lying down, appear to result from traction on the renal vessels.
Why is the donor kidney positioned in the iliac fossa?
The site supports the transplanted kidney, so that traction is not placed on the surgically anastomosed vessels. The renal artery and vein are joined to the external iliac artery and vein, respectively, and the ureter is sutured into the urinary bladder.
Why in males, can hematuria and/or proteinuria, left flank pain, vomiting, and left testicular pain result from renal vein entrapment syndrome?
Downward traction on the SMA may compress the left renal vein resulting in renal vein entrapment syndrome. The symptoms appear in men because it is related to the left testicular vein draining into the left renal vein proximal to the compression.
What happens to the mesoderm during gastrulation?
It forms three bilateral columns– including the intermediate mesoderm.
What does the intermediate mesoderm form in the cervical region? thoracic and lumbar regions?
cervical region: rudimentary pronephros (nonfunctional excretory system that disappears)
thoracic and lumbar region: during regression of the pronephros, mesonephros and mesonephric (aka wolffian duct)
What does segmentation of the mesonephros create?
epithelium-lined excretory tubules that open into the eptihelium-lined mesonephric duct, which terminates in the cloaca.
Lengthening of the excretory tubules forms S-shaped loops that acquire a glomerulus (loop of capillaries) at their medial ends.
What forms the glomeruli that are associated with Bowman’s capsules?
Angiogenic outgrowths from the dorsal aorta form the glomeruli that become associated with Bowman’s capsules, which differentiate at the medial ends of the excretory tubules.
What constitutes the renal corpuscles?
glomeruli and Bowman’s capsules
What happens to the mesonephric excretory tubules in females? in males?
females: the mesonephric excretory tubules and all but the distal end of the mesonephric duct degenerate and disappear
males: caudal excretory tubules and the mesonephric duct persist to participate in formation of the genital system
What forms the ureteric bud?
epithelial outgrowth from the distal mesonephric duct near its entrance into the cloaca.
It grows into the metanephros which is derived from the intermediate mesoderm in the sacral region
What forms the renal pelvis? collecting tubules?
Within the metanephros, dilation of the ureteric bud forms the renal pelvis that splits into multiple calyces
epithelial outgrowths from the calyces create collecting tubules and branches of the tubules penetrate deeper into the metanephros
What makes up a nephron?
At the terminal end of each collecting tubule, the surrounding metanephros forms a nephron
Each nephron consists of an excretory tubule and its associated renal corpuscle.
What happens as the excretory tubule lengthens?
It differentiates into a distal convoluted tubule, which unites with the collecting tubule (U-shaped loop of Henle) and a proximal convoluted tubule that unites with Bowman’s capsule.
How many nephrons reside in each kidney at birth?
Nephron formation continues until birth when approximately 1 MILLION nephrons reside in each kidney.
What causes the kidneys to ascend to the lumbar region?
Remember the ureteric bud and metanephros originate in the sacral region and diminution of body curvature and lengthening of the lumbar and sacral regions cause the kidneys to ascend into the lumbar region
Why do anuria, oligohydramnios and hypoplastic lungs characterize relatively uncommon bilateral renal agenesis? Why is unilateral agenesis compatible with life?
Bilateral renal agenesis results in renal failure. The baby presents with Potter sequence.
When does a horseshoe kidney occur and is it fatal?
The kidneys are pushed so close together during their passage through the arterial fork, that the lower poles fuse, forming a horseshoe kidney. It is usually at the lower lumbar vertebrae, since its ascent is prevented by the root of IMA.
NOT FATAL?
What does the renal cortex cover?
It covers the cone-shaped pyramids (which constitute the renal medulla).
What does the coalescence of collecting tubules in the medulla form?
Large collecting ducts