Kidneys & Suprarenal Glands Flashcards
What are the endocrine functions of the kidney?
- Production of renin for angiotensin system
2. Release of erythropoietin for RBC production
Where is the kidney located? What type of organ is it?
Retroperitoneal / extraperitoneal
Left is often higher than the right
Superior pole at level of 11th / 12th ribs
Extend inferiorly down to LV3
What is the renal sinus? What does it often contain?
Fat-filled cavity lateral to the hilum of the kidney through which the vessels entering the hilum pass.
Often contains some perirenal fat
What is the layer below the fibrous capsule of the kidney called? What are its inward projections between pyramids of adrenal medulla?
Renal cortex - inward protections of cortex are renal columns
What makes up the renal medulla, and what is at their apex?
~18 cone-shaped renal pyramids, bases are directed outwardly.
Apex - renal papilla which is capped by a minor calyx extending into renal sinus.
How does urine enter the ureter?
Renal papilla -> minor calyces -> major calyces -> renal pelvis -> ureter
Where do the ureters run?
Retroperitoneally, on anterior surface of p. major, passing posteriorly to testicular / ovarian vessels. Courses anterior to bifurcation of common iliac, making sharp bend over pelvic brim and into bladder.
What is the renal fascia / what does it surround?
Membranous connective tissue surrounding the perirenal fat, making a space called the perinerphric space. It merges medially with the adventitia of the renal vessels.
What is the renal fascia continuous with inferiorly? Does it extend medially across midline?
Inferiorly: connective tissue surrounds ureter all the way to the bladder
The perinephric spaces do not communicate across midline, but offers an avenue for hemorrhaging or infection to spread to the pelvis (via fascia around ureter)
Is the suprarenal gland separated from the kidney? Is it still in the space?
Yes, by a thin fascial septum from the renal fascia. Still part of the perinephric space
What is perirenal vs pararenal fat in terms of location?
Perirenal - inside fibrous capsule of kidney + renal fascia
Pararenal - outside of renal fascia, covered by parietal peritoneum anteriorly and transversalis fascia posteriorly. Invests kidney + suprarenal glands
What is perirenal vs pararenal fat in terms of function?
Perirenal - temperature control for best filtration + hormone release
Pararenal - you just have more of this if you’re fat
What structures are related to the anterior surface of the right kidney?
Right visceral lobe of liver, 2nd part of duodenum, right / hepatic flexure of colon, small intestine
What structures are related to the posterior surface of the right kidney?
12th rib + diaphragm, aponeurosus of transversus abdominus, quadratus lumborum, psoas major
What structures are related to the posterior surface of the left kidney?
11th + 12th rib, diaphragm, aponeurosus of transversus abdominus, quadratus lumborum, psoas major
What structures are related to the anterior surface of th left kidney?
Stomach, spleen, left flexure of colon, jejunum, pancreas
Where do the left and right renal arteries course?
At about LV1 / LV2 level, they come from aorta, running posterior to the renal veins (+right is posterior to IVC). They divide into anterior + posterior branches around the renal pelvis before branching into segmental branches which do not anastomose
What is the course of the right renal vein?
Drains directly into IVC, passing posteriorly to descending duodenum + head of pancreas
What is the course of the left renal vein? What are its tributaries?
Passes anterior to abdominal aorta just below origin of SMA, but posterior to pancreas. It is longer than right and receives left suprarenal vein + left gonadal vein
How many segmental arteries are given off by the renal arteries and why are they important?
5 on each side, corresponding to the lobes of the kidneys. They have no anastomotic connections, and thus obstruction of a segment artery will result in complete loss of the lobe that it supplied
What structure crosses the left ureter but not the right?
Inferior mesenteric artery and vein.
Both are crossed by the gonadal vessels
Where are the three internal constriction sites where kidney stones can become lodged?
What is a ureter made of?
- Renal pelvis to ureter transition
- Ureter crossing the common iliac
- Ureter entering bladder
A ureter is a smooth muscle tube
How is blood supply to the ureter given?
Ureteric branches that supply it regionally:
- Renal arteries (proximal 5-7 cm)
- Abdominal aorta
- Gonadal arteries
- Common / internal iliac branches
- Superior and inferior vesical
How do sympathetics reach the kidney?
Preganglionics from lesser and least splanchnic nerves (T10-T12), synapse in aorticorenal ganglion, postganglionics enter along the renal artery and its branches
