Kidneys & Suprarenal Glands

Question 1

What are the endocrine functions of the kidney?

Answer 1

1. Production of renin for angiotensin system

2. Release of erythropoietin for RBC production

Question 2

Where is the kidney located? What type of organ is it?

Answer 2

Retroperitoneal / extraperitoneal
Left is often higher than the right
Superior pole at level of 11th / 12th ribs
Extend inferiorly down to LV3

Question 3

What is the renal sinus? What does it often contain?

Answer 3

Fat-filled cavity lateral to the hilum of the kidney through which the vessels entering the hilum pass.

Often contains some perirenal fat

Question 4

What is the layer below the fibrous capsule of the kidney called? What are its inward projections between pyramids of adrenal medulla?

Answer 4

Renal cortex - inward protections of cortex are renal columns

Question 5

What makes up the renal medulla, and what is at their apex?

Answer 5

~18 cone-shaped renal pyramids, bases are directed outwardly.

Apex - renal papilla which is capped by a minor calyx extending into renal sinus.

Question 6

How does urine enter the ureter?

Answer 6

Renal papilla -> minor calyces -> major calyces -> renal pelvis -> ureter

Question 7

Where do the ureters run?

Answer 7

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.

Question 8

What is the renal fascia / what does it surround?

Answer 8

Membranous connective tissue surrounding the perirenal fat, making a space called the perinerphric space. It merges medially with the adventitia of the renal vessels.

Question 9

What is the renal fascia continuous with inferiorly? Does it extend medially across midline?

Answer 9

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)

Question 10

Is the suprarenal gland separated from the kidney? Is it still in the space?

Answer 10

Yes, by a thin fascial septum from the renal fascia. Still part of the perinephric space

Question 11

What is perirenal vs pararenal fat in terms of location?

Answer 11

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

Question 12

What is perirenal vs pararenal fat in terms of function?

Answer 12

Perirenal - temperature control for best filtration + hormone release
Pararenal - you just have more of this if you’re fat

Question 13

What structures are related to the anterior surface of the right kidney?

Answer 13

Right visceral lobe of liver, 2nd part of duodenum, right / hepatic flexure of colon, small intestine

Question 14

What structures are related to the posterior surface of the right kidney?

Answer 14

12th rib + diaphragm, aponeurosus of transversus abdominus, quadratus lumborum, psoas major

Question 15

What structures are related to the posterior surface of the left kidney?

Answer 15

11th + 12th rib, diaphragm, aponeurosus of transversus abdominus, quadratus lumborum, psoas major

Question 16

What structures are related to the anterior surface of th left kidney?

Answer 16

Stomach, spleen, left flexure of colon, jejunum, pancreas

Question 17

Where do the left and right renal arteries course?

Answer 17

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

Question 18

What is the course of the right renal vein?

Answer 18

Drains directly into IVC, passing posteriorly to descending duodenum + head of pancreas

Question 19

What is the course of the left renal vein? What are its tributaries?

Answer 19

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

Question 20

How many segmental arteries are given off by the renal arteries and why are they important?

Answer 20

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

Question 21

What structure crosses the left ureter but not the right?

Answer 21

Inferior mesenteric artery and vein.

Both are crossed by the gonadal vessels

Question 22

Where are the three internal constriction sites where kidney stones can become lodged?

What is a ureter made of?

Answer 22

1. Renal pelvis to ureter transition
2. Ureter crossing the common iliac
3. Ureter entering bladder

A ureter is a smooth muscle tube

Question 23

How is blood supply to the ureter given?

Answer 23

Ureteric branches that supply it regionally:

1. Renal arteries (proximal 5-7 cm)
2. Abdominal aorta
3. Gonadal arteries
4. Common / internal iliac branches
5. Superior and inferior vesical

Question 24

How do sympathetics reach the kidney?

Answer 24

Preganglionics from lesser and least splanchnic nerves (T10-T12), synapse in aorticorenal ganglion, postganglionics enter along the renal artery and its branches

Question 25

What is the sympathetic function in the kidney? PANS?

Answer 25

Decrease blood flow and glomerular filtration rate. Increase tubular sodium + water reabsoprtion. Increase renin release.

Absence of this allows kidneys to function normally.

PANS to the kidney is not understood

Question 26

What is the SANS innervation to the ureter?

Answer 26

First part by least splanchnic (T12)

Rest by lumbar splanchnics (L1-L2)

Question 27

How is pain referred from kidney and ureter?

Answer 27

With sympathetics.
Kidney: T10-T12
Ureter: T12-L2, along posterior costal margin.
L1 dermatomes of iliohypogastric and ilioinguinal will be affected
L2 dermatome of genital branch of genitalfemoral nerve will be affected

Question 28

Where are the IVC and right lobe of the liver in relation to the right suprarenal gland?

Answer 28

anterior

Question 29

How is the aorta related to the left suprarenal gland?

Answer 29

medially

Question 30

Why does the adrenal medulla stain darker?

Answer 30

Melanin accumulates as a byproduct of catecholamine production

Question 31

What is the innervation of chromaffin cells of the adrenal medulla?

Answer 31

Preganglionic fibers directly from greater splanchnic nerve (T5-T9)

Question 32

What are the sources of the three arteries of the suprarenal glands?

Answer 32

1. Superior suprarenal artery - from inferior phrenic
2. Middle suprarenal artery - from abdominal aorta above renal artery
3. Inferior suprarenal artery - from renal artery

Question 33

What are the veins of the adrenal glands and where do they drain?

Answer 33

Each has one suprarenal vein

Left suprarenal vein: Drains into renal vein
Right suprarenal vein: Drains directly into IVC

Question 34

What are the sensory afferents and PANS of the adrenal glands?

Answer 34

I tricked you. There aren’t any

Question 35

What is the sympathetic innervation of the adrenal cortex?

Answer 35

Greater splanchnic nerve -> celiac ganglion -> postganglionics supplying blood vessels

Question 36

What is a horseshoe kidney?

Answer 36

As right and left kidneys ascend out of pelvis, they can fuse at midline and be stopped by inferior mesenteric artery

Question 37

What are accessory renal arteries?

Answer 37

Some people have arteries arising from abdominal aorta to the kidney which do not go through the hilum

Question 38

What is Addison’s disease?

Answer 38

Autoimmune disease that damages adrenal cortex. Leads to dropped cortisol and aldosterone levels, which are vital to life. There will be problems with metaolism, blood pressure, water balance, etc.

Question 39

Where do kidney transplants typically take place and why?

Answer 39

Pelvis / lower abdomen, because it’s easiest to get in here, and blood supply to the ureter is regional. Dissected ureters with segments extending beyond 7cm do not survive a transplant and undergo ischemia / necrosis, so they have to place it lower to be supplied by renal artery!!