8: Renal Anat And Histo Flashcards
Spinal levels of the kidney
T12-L3
Which kidney is slightly lower and why?
Right, due to liver
What plane runs thru superior pole of right kidney, and what level is that at?
Transpyloric plane, L1
What artery do the ureters cross?
Common iliac
Three points of constriction of the ureters (where stones may get stuck)
- Uretopelvic junction
- Over common iliac
- Uretovesical junction
Renal blood flow from aorta to IVC (15 vessels)
- Aorta
- Renal artery
- Segmental artery
- Interlobar artery
- Arcuate artery
- Interlobular artery
- Afferent arterioles
- Glomerulus
- Efferent arterioles
- Peritubular caps/vasa recta
- Interlobular veins
- Arcuate veins
- Interlobar veins
- Renal vein
- IVC
Sympathetics to the kidney
Renal plexus -> lesser, least, and lumbar splanchnic nerves
Where do lesser and least splanchnic nerves synapse?
Aorticorenal ganglion
Parasymp innervation to kidney
Vagus N
Path from renal papilla to ureter (6 steps)
- Renal papilla
- Minor calyces
- Major calyces
- Renal sinus
- Renal pelvis
- Ureter
Contents of cortex vs medulla
Cortex: renal corpuscles, convoluted and straight tubules, portion of CDs
Medulla: renal columns, renal pyramids
Cortical (medullary) rays
Aggregations of CDs and straight tubules between corpuscles within the cortex
Renal interstitium
Fibroblasts that produce erythropoietin depending on O2 levels
Cortical labyrinth
Between medullary rays, contain renal corpuscles, convoluted tubules, and CDs
Uriniferous tubule
Nephron + collecting tubule
What is a nephron made up of
Renal corpuscle + renal tubules
Mesangial cells are like what?
Pericytes
Where are mesangial cells?
In renal corpuscles, enclosed in the glomerular basement membrane
Four functions of mesangium
- Phagocytosis/endocytosis of debris
- Structural support
- Secretion
- Modulation of glomerular distention (contractile)
What does prolif of mesangium mean?
Certain kidney diseases
Juxtamedullary nephrons vs cortical nephrons: which have long vs short loops of Henle
Juxtamedullary: long
Cortical: shortical
Peritubular capillaries
Surround convoluted tubules with fenestrations to re-uptake water and salt
Vasa recta
Surrounding LOH for countercurrent exchange and concentration
Descending vs ascending vasa recta
Descending: continuous
Ascending: has fenestrations
JGA function
BP regulation - activates RAAS
Where is the JGA
Near vascular pole of renal corpuscle and terminal portion of distal straight tubule
Macula densa cells
Chemo receptors in JGA that sense low Na -> trigger renin release
Urothelium / transitional ep
Stratified with dome-shaped apical surfaces in an empty bladder
Functions of transitional ep
- Impermeable to water
2. Accommodate to distention and flatten out
Three layers of transitional ep and their functions
- Superficial: stretch and relax
- Intermediate: sliding
- Basal: stem cells
Uroplakin
Form plaques in urothelium that prevent diffusion of urine into cells
What are a series of uroplakin plaques called?
Fusiform vesicles
Three ways reflux is prevented in ureters
- Bladder distention compresses ureters
- Contraction of SM of bladder compresses ureters
- Ureters enter into bladder obliquely
Internal vs external urethral sphincter
Internal: around internal urethral orifice, involuntary
External: in membranous urethra, voluntary control
Which sex’s urethra is shorter?
Female
Three main segments of the male urethra + the histology involved
- Prostatic: urothelium
- membranous urethra: pseudostratified columnar
- Penile/spongy urethra: transitions to stratified squamous at the end
Prostatic urethra: what enters here?
Ejaculatory ducts, many small prostatic ducts
What does membranous urethra pass thru
Deep perineal pouch
What surrounds the spongy urethra in males?
Corpus spongiosum
What empties into the spongy urethra
Cowper’s glands, urethral glands
