Renal System: Anatomy/Embryo Review Flashcards
(47 cards)
The ureters descend on the posterior abdominal wall on the surface of what muscle?
psoas major
and cross the pelvic brim at the bifurcation of the common iliac arteries into the internal and external iliacs.
What structures enters/exits the ‘hilum of the kidney’?
the renal vessels, lymphatics, nerves, and proximal ureter
What is the order from anterior to posterior of the structures entering the hilum?
- renal vein
- renal artery
- renal pelvis/ureter
Projections of the renal cortex called the _____ extend in between the triangularly shaped medullary pyramids into the center of the kidney
renal columns
The apex of medullary pyramids converge onto what structures?
The apical projection (aka renal papilla) is surrounded by a minor calyx.
The minor calyx receives urine and these represent the most proximal part of the tube that will eventually form the ureter.
What do 2-3 minor calyx combine to form?
Several minor calyces unite in the renal sinus to form a major calyx and in turn, 2‐3 major calyces unite to form the renal pelvis.
The renal pelvis is the funnel‐shaped proximal end of the ureter. It occupies a posterior position in the renal hilum relative to the renal vein and artery.
What does a renal corpuscle consist of?
The renal corpuscle consists of the glomerular capsule (aka Bowman’s capsule) which covers a tuft of capillaries called the glomerulus
Describe the flow of filtrate in the renal nephron.
The proximal convoluted tubule extends from the capsule and then the tubule changes to a straight tubule called Henle’s loop (the straight tubule).
This is followed by the distal convoluted tubule which empties into a collecting duct.
The collecting ducts (usually 10‐20) empty the renal papilla into the minor calyx.
T or F. The kidneys are retroperitoneal
T. They are embedded in
fat and connective tissue.
The ureters are as well.
What spinal segments does the vertical positioning of the kidneys on the posterior abdominal wall correspond to?
T12-L3, though the right kidney is usually slightly lower than the left due to its relationship with the liver
The right kidney is usually related to the 12th rib posteriorly, while the left kidney is usually related to
ribs 11 and 12 posteriorly.
The hilum of BOTH kidneys lie in the same horizontal plane as which anatomical landmark?
the transpyloric plane
Describe the fascial layers surrounding the kidneys.
They are surrounded by a dense layer of renal fascia which consists of anterior and posterior laminae that splits from the transversals fascia.
Deep to the renal fascial is a layer of perirenal (or perinephric) fat which completely surrounds the kidney and serves to cushion and protect the kidney, which is quite fragile.
What lies directly outside the anterior and posterior laminae?
There is an additional layer of pararenal (or paranephric) fat external to the renal fascia which adds additional support and protection
What do the two layers of renal fascia do superiorly? Inferiorly?
The two layers of renal fascia are fused superiorly and continue across the hilum of each kidney where they fuse with the adventitia of the renal vessels
The facial layers are open inferiorly, to allow downward movement of the kidney with movements of the diaphragm
Note: The renal fascia must be incised in any surgical approach to the kidney.
What determines the potential spread of peritoneal abscess (pus around the kidneys)?
The fascia at the renal hilum usually attaches to the renal vessels and ureter, usually
preventing the spread of infection to the contralateral side.
However, pus from an abscess (or blood from an
injured kidney) may descend into the pelvic cavity between the loosely attached anterior and posterior layers of renal fascia.
What is nephroptosis?
dropped kidney. This occurs when abnormally mobile kidneys descend more than normal when the body is
erect.
How is nephroptosis distinguished from an ectopic kidney?
Distinguishable due to the presence of a ureter of normal length that has loose coiling or kinks due to the reduced distance between kidney and bladder.
Nephroptosis may be accompanied by intermittent pain in the renal region due
to stretch forces placed on the renal vessels. This pain is usually relieved by lying down.
This is one of the reasons transplant kidneys are placed in the iliac fossa of the greater pelvis.
Where do the renal arteries branch from the aorta?
slightly below the origin of the superior mesenteric branch (LV1/LV2)
T or F. The left renal artery is shorter than the right
T. Since the aorta lies to the left of the midline. The right
renal artery passes BEHIND the IVC to reach the right kidney.
Describe the branches each renal artery
Each renal artery branches before entering the hilum of the kidney into an anterior and a posterior branch which supply the renal parenchyma.
The anterior branch further divides into four segmental arteries.
The renal arteries are also give off an inferior suprarenal artery to the lower pole of the gland, as well as a small ureteric artery.
There are often accessory renal vessels (~30%). These sometimes enter the poles of the kidneys.
T or F. The left renal vein is shorter than the right
F. The right is shorter
What important vein does the left renal vein receive?
The left gonadal (testicular or ovarian) vein, whereas the right gonadal vein empties directly into the IVC
Describe the ‘nutcracker’ relationship of the SMA.
the superior mesenteric artery descends over the left renal vein more superiorly and the 3rd part of the duodenum more inferiorly
What is SMA syndrome?
The SMA syndrome is compression of the duodenum between the SMA and aorta.
It has a roughly 1 in 3
mortality rate. Fortunately, it is quite rare.
