renal Flashcards
Anatomical location of the kidneys?
Bilateral between the 12th thoracic and 3rd lumbar vertebrae.
What is the kidney composed of?
- outer cortex containing the glomeruli
2. inner medulla containing the tubules and collecting ducts that drain into the calyces.
The calyces join to form what?
The renal pelvis.
What are the calyces continuous with?
The upper end of the ureter.
What is the urine forming unit of the kidney?
The nephron
What are nephrons composed of?
- glomerulus
- proximal tubule
- hairpin loops of Henle
- distal tubule
- collecting duct
The glomerulus contains loops of capillaries that loop in what structure?
Bowman capsule
Filtration membrane for the formation of primary urine is found where?
capillary walls
What are the layers of glomerular capillary?
- endothelium
- basement membrane
- epithelium
The epithelium is composed of ________ that interlock to provide _________ ______.
podocytes, filtration slits
What structures lie between and support the glomerular capillaries in the Bowman capsule?
Mesangial cells and matrix
What cells secrete renin and are located around the afferent arteriole?
Juxtaglomerular cells
What cells are located around the afferent arteriole?
Juxtaglomerular cells
What are contiguous with juxtaglomerular cells and are located in the DCT?
sodium sensing macula densa cells
What is the name of the space between the visceral and parietal epithelium?
The Bowman capsule
The proximal tubule is lined with _________to increase surface are and enhance reabsorption
microvilli
What is the function of the hair-pin shaped loops of Henle?
selectively transport solutes and water, contributing to the hypertonic state of the medulla
What structure adjusts acid base balance by excreting acid into the urine and forming new bicarb ions?
distal tubule
What are the purpose of principal cells?
They resorb sodium and water and excrete potassium and intercalated cells that secrete hydrogen or bicarb and potassium
Where are principal and intercalated cells located?
The collecting duct
What do intercalated cells do?
secrete hydrogen or bicarbonate and potassium
What extends from the renal pelvis to the posterior wall of the bladder?
Ureters
Where are the kidneys located?
retroperitoneal/posterior
What is the function of the renal pyramid?
where urine is produced
What is the renal papilla?
Forms urine. It’s the apex of the pyramid.
What structure drains into the minor calyces?
Renal papilla
What is the function of minor calyces?
collect urine from the renal pyramids
What is the function of major calyces?
collect urine from 2-3 minor calyces
This structure collects urine from the major calyces and forms a “duct” that becomes continuous with the ureter
renal pelvis
What are the three areas in which a kidney stone is most likely to be lodged?
- junction of renal pelvis and ureter (ureteropelvic junction)
- as ureter passes over pelvic brim
- as the ureter enters the bladder
The juxtaglomerular apparatus regulates
- renal blood flow
- glomerular filtration
- renin secretion
What is the RBF?
Volume of blood flow through the glomerular capillaries of both kidneys per min
RBF = 1.2 L/min
Approx. 20-30% of CO
RPF
Renal plasma flow. Volume plasma flowing through glomerular capillaries of both kidneys per minute.
Avg RPF = 600-700 ml/min
RPF = RBF x (1.00 - Hct) should be 660 ml/min
GFR
Volume of plasma that is filtered into Bowman’s capsule.
Indicator of glomerular health! 120 ml/min
GFR = 20% x RPF
.2 x 600 ml/min
What % of RPF travels to the peri tubular capillaries/vasa recta?
Approx. 80%
How much of the GFR is re absorbed back into the bloodstream?
Approx. 98-99% re absorbed into the peri tubular caps/vasa recta.
Filtration Fraction (FF)
Ratio of GFR to RPF
Average FF = 0.2
ie 120/660
Calculate urine output
Urine output = GFR x 1.5%
120 ml/min x .015 = 1 - 2 ml/min
How much plasma do the kidneys filter in a day?
180 L/day
Average daily urine output?
1-2 L/day
How much does the kidney re absorb each day?
178-179 L/day
How long does it take to filter entire plasma volume?
45 min
How is RBF / GFR regulated?
- Auto regulation
- Neuroregulation
- Hormonal feedback
THE NET RESULT OF THE THREE DETERMINES ACTUAL RBF/GFR
GFR has what type of relationship with RBF?
They are directly related.
If decrease in RBF, then decrease in GFR
Can go other way too.
