Abdomen 4 - Kidneys & Suprarenal glands

Question 1

what is the function of the kidneys?

Answer 1

regulates solute levels - filtering blood to remove waste products & concentrate them into urine with water

secretes hormones - for blood pressure and solute regulation

Question 2

what is the peritoneal classification of the kidneys?

Answer 2

retroperitoneal

Question 3

at what vertebral level do the kidneys sit?

Answer 3

T12-L3 - in the posterior abdominal cavity

Question 4

why is the right kidney lower & smaller than the left?

Answer 4

liver on the right side takes up lots of space

Question 5

what structure is the medial border of the kidney close to?

Answer 5

close to the renal hilum - entry/exit point of renal neurovasculature, lymph vessels & ureter

Question 6

what are the superior & inferior poles of the kidney?

Answer 6

upper and lower tips of the kidney

Question 7

what is the order of protective coverings around the kidney, from innermost to outermost?

Answer 7

renal capsule
perinephric fat
renal fascia
paranephric fat

Question 8

what is the renal capsule?

Answer 8

tough protective outer layer that directly covers the kidney’s surface

Question 9

what fascia is the renal fascia continuous with?

Answer 9

transversalis fascia + fascia on diaphragm

(renal fascia forms collagen threads connecting it to transversalis fascia & peritoneum)

Question 10

what is the clinical significance of the midline continuity of the renal fascia between kidneys?

Answer 10

potential spread of infection between kidneys via the renal fascia

Question 11

what is the paranephric fat of the kidneys between?

Answer 11

between the renal fascia & peritoneum

Question 12

what mainly protects the kidneys?

Answer 12

minimal bony protection from ribs 11-12

mainly protected by fat & fascia layers - renal capsule, perinephric fat, renal fascia & paranephric fat

Question 13

what 3 muscles cover the posterior surface of the kidneys? (from medial to lateral)

Answer 13

psoas major
quadratus lumborum
transversus abdominis

Question 14

what organ covers the anterior surface of the inferior pole of both kidneys?

Answer 14

small intestine (jejunum & ileum)

Question 15

what covers the anterior surface of the superior pole of both kidneys?

Answer 15

suprarenal/adrenal glands (right and left)

Question 16

from anterior to posterior/top-bottom, what is the order of appearance of the contents of the renal hilum?

Answer 16

renal vein
renal artery
renal ureter
(V-A-U)

Question 17

what does the renal hilum give passage to?

Answer 17

lymphatic vessels
sympathetic fibres
renal vein
renal artery
ureter

Question 18

what is the role of the sympathetic fibres entering via the renal hilum?

Answer 18

control blood flow by controlling vasoconstriction

more blood flow = more filtration = more urine production

Question 19

how does the right renal artery pass relative to the IVC?

Answer 19

passes posterior to the IVC (right renal artery behind IVC)

Question 20

how does the left renal vein pass relative to the SMA? what clinical condition is this linked to?

Answer 20

left renal vein passes under/inferior to the SMA

linked to nutcracker syndrome - compression of the renal vein by the SMA & aorta at the L1-2 boundary

Question 21

what is nutcracker syndrome? what clinical consequences does this lead to?

Answer 21

compression of the left renal vein between the SMA & aorta at the L1-2 boundary

compression of left renal vein
- restricted left venous return
- increased blood pressure in left kidney
- leads to left kidney failure

Question 22

what is the renal sinus? what does it contain?

Answer 22

a cavity continuous with the renal pelvis, filled with perinephric fat and containing blood vessels and nerves

Question 23

what is the renal pelvis?

Answer 23

expanded upper part of the ureter for urine collection - all the major calyxes converge on the renal pelvis

Question 24

what are the spaces in the renal pelvis filled by?

Answer 24

perinephric fat

Question 25

what is the renal cortex? what does it contain?

Answer 25

pale outer band of tissue surrounding the inner renal medulla - contains glomeruli (filtration units)

Question 26

what are the renal columns?

Answer 26

extensions of the renal cortex between the pyramids - contain glomeruli & blood vessels

Question 27

what is the renal medulla composed of?

Answer 27

pyramids - with nephron loops (to concentrate urine) & collecting ducts (to transport urine) renal papilla (apex of the pyramids) - collecting ducts empty urine into the minor calyxes at the renal papilla

Question 28

what are renal pyramids and their role?

Answer 28

triangular structures in the renal medulla they concentrate urine and transport it via collecting ducts

Question 29

how does urine flow through the kidney?

Answer 29

collecting ducts in the medulla converge - minor calyxes - major calyxes - renal pelvis - ureter empties into ureter via smooth muscle contractions of the calyxes

Question 30

how is urine propelled through the kidney structures into the ureter?

Answer 30

smooth muscle contractions in the calyxes propel urine via peristalsis

Question 31

what sort of innervation do the kidneys mainly have? why?

Answer 31

mainly sympathetic innervation - vasoconstriction controls blood flow, controlling filtration rate and thus urine production

Question 32

describe the order of arterial supply of the kidneys from the renal artery

Answer 32

renal artery (5) segmental arteries = one for each of the 5 segments lobar arteries = a lobe consists of a renal pyramid & superior cortex surrounding it interlobar arteries arcuate arteries = arch over base of pyramid interlobular arteries = ascend into cortex afferent glomerular arterioles = into Bowman's capsule

Question 33

describe the order of venous drainage starting from the efferent glomerular veins of Bowman's capsule

Answer 33

efferent glomerular veins from Bowman's capsule interlobular veins arcuate veins interlobar veins multiple renal veins - converge right/left renal vein

Question 34

where are the suprarenal (adrenal) glands located?

Answer 34

on the superior pole of each kidney, enclosed in renal fascia

Question 35

how do the shapes of the right and left adrenal glands differ?

Answer 35

right is pyramid-shaped left is crescent-shaped

Question 36

what are the two main parts of the suprarenal gland?

Answer 36

yellow cortex - derived from mesoderm brown medulla - derived from neural crest

Question 37

what does the suprarenal cortex secrete?

Answer 37

corticosteroids androgens

Question 38

what does the suprarenal medulla secrete?

Answer 38

catecholamines (adrenaline & noradrenaline)

Question 39

how do the suprarenal cortex & medulla differ in what they secrete?

Answer 39

cortex secretes androgens & corticosteroids medulla secretes catecholamines - e.g. adrenaline, noradrenaline

Question 40

how does the adrenal medulla function similarly to the sympathetic nervous system?

Answer 40

acts like a sympathetic postganglionic neuron - releases adrenaline & noradrenaline into the bloodstream

Question 41

why do the suprarenal glands have a highly vascularized blood supply?

Answer 41

to support rapid hormone production and release

Question 42

what are the three arteries supplying the suprarenal glands? where do they each arise from?

Answer 42

superior suprarenal artery - from inferior phrenic artery middle suprarenal artery - direct branch from aorta at T12 inferior suprarenal artery - branch of renal artery

Question 43

what is the venous drainage pattern of the suprarenal glands?

Answer 43

right suprarenal vein drains directly into IVC left suprarenal vein drains into left renal vein - then IVC

Question 44

which suprarenal vein drains directly into the IVC?

Answer 44

right suprarenal vein

Question 45

which suprarenal vein first drains into the left renal vein before reaching the IVC?

Answer 45

left suprarenal vein

Question 46

which plexus innervates the suprarenal glands?

Answer 46

renal plexus (one of the pre-aortic plexi)

Question 47

what makes the sympathetic innervation of the suprarenal glands unique?

Answer 47

there is no postganglionic neuron - preganglionic sympathetic fibres go directly to the adrenal medulla

Question 48

what type of autonomic innervation do the adrenal gland have?

Answer 48

sympathetic

Question 49

why is the adrenal medulla considered a neuroendocrine organ?

Answer 49

acts like a postganglionic sympathetic neuron - releases adrenaline & noradrenaline directly into the bloodstream

Question 50

what type of neurotransmitters does the adrenal medulla secrete?

Answer 50

catecholamines - adrenaline & noradrenaline

Question 51

what structure do the pyramids of the kidney contain?

Answer 51

collecting ducts

Question 52

what is nephroptosis?

Answer 52

dropped kidneys - insufficient fusion of renal fascia layers lead to kidneys being abnormally mobile and descending adrenal glands remain in place despite kidneys dropping due to their attachment to the diaphragm

Question 53

how are the suprarenal glands attached to the diaphragm?

Answer 53

by diaphragmatic crura