Quiz 3 Flashcards
Where is the GBM found relative to the glomerulus and Bowman’s space?
Through what structure in the glomerular capillary does plasma flow before crossing the GBM? After crossing, it passes between podocytes through what structure in order to enter Bowman’s space?
Fenestrations
Filtration slits
What is the GFR?
The sum of the individual filtration rates of all glomeruli in both kidneys
What is the optimal GFR of normal kidney function? What range is still considered normal?
What range of GFR values is considered kidney disease?
What range of GFR values is considered kidney failure?
What substances should not pass through the GBM?
What is the equation that represents how to theoretically determine GFR with Starling forces?
How much ATP is required per minute for glomerular filtration to occur?
What happens to Glomerular capillary oncotic pressure as plasma moves from the AGA to the EGA?
It increases as plasma volume is filtered into BC, so that pressure is equalized at the EGA and no further filtration occurs
What substance is used to measure GFR in experiments? What clinical substance is used to approximate GFR for patients?
How is creatinine clearance calculated?
What is RPF?
Why is Para-AminoHippuric acid (PAH) used in order to estimate renal plasma flow (RPF)?
What is the equation used to calculate RPF (using PAH)?
What equation can be used to calculate RPF involving HCT?
What is the filtration fraction of the kidneys?
*Also know it is the ratio of the GFR to the RPF
What is the relationship between FF, GFR, and RPF?
What effect does dilation of the AGA have on RPF? On GFR? on FF? What is an example of a substance that causes this effect?
What effect does constriction of the AGA have on RPF? On GFR? on FF? What is an example of a substance that causes this effect?
What effect does constriction of the EGA have on RPF? on GFR? on FF? What is an example of a substance that causes this effect?
What effect does increased albumin in the plasma have on RPF? On GFR? On FF?
What can cause an increase in hydrostatic pressure in Bowman’s space?
How does increasing the hydrostatic pressure in Bowman’s space affect GFR? RPF? FF? What can cause this to occur?
In absence of autoregulation of GFR what would occur in situations of high BP? Of low BP?
What two autoregulation mechanisms are used by the kidneys to regulate GFR and RPF over a wide range of MAP?
How does the myogenic mechanism work in autoregulation of GFR?
How does the tubuloglomerular feedback mechanism work in autoregulation of the GFR?
What are some limits on auto-regulation of GFR? What drugs can interfere with autoregulation?
What is filtrate called once it moves from BS into the nephron tubules?
Tubular fluid
What is the direction and exchange rate of Na+ and K+ in the tubular cell Na+/K+ ATPase?
What are two hormones that stimulate the Na+/K+ ATPases in renal tubular cells?
Insulin
Epinephrine
Which tubule of the nephron experiences the highest volume of substance traffick?
The proximal tubule
Which renal tubule is responsible for absorption of all glucose and AA’s, as well as most of the HCO3?
What is the proximal tubule responsible for absorbing and secreting?
What PCT transporter is principally responsible for reabsorption of glucose? What substance is co-transported?
Most symporters in the PCT use what substance for cotransport?
Na+
What two mechanisms allow for water reabsorption in the PCT?
Aquaportins (AQP1)
Tight junctions
How is bicarbonate reabsorbed in the PCT? Which carbonic anhydrase is found in the apical surface of the cell, and which on the interior?
As water diffuses through the tight junctions in the PCT what molecules are able to follow it as a result of solvent drag?
T/F: The DTL of the loop of Henle is permeable to salt but NOT water
False, the exact opposite
As tubular fluid travels through the DTL of the loop of Henle, what is the change in osmolality?
300 mOsm to about 1200 mOsm
What types of channels allow Na+ reabsorption in the TAL of the loop of Henle but not water?
Where is magnesium predominantly reabsorbed in the renal tubules?
What molecules are reabsorbed from the tubular fluid by the NKCC2 transporters?
Na+
K+
2 Cl-
What is the counter-current multiplier? What two processes is it essential for?
What transporter is the target of loop diuretics? What effect does this have on the tonicity of the renal medulla? What is the net effect on urine production?
Why can loop diuretics cause a decrease in plasma potassium levels?
Which transporter allows K+ to leak back into the filtrate in the TAL?
What transporter in the DCT is responsible for reabsorbing Na+ and Cl- ions from filtrate in to DCT cells? What type of diuretics target this transporter?
NCC symporter
The CD of the kidneys are impermeable to water under what condition? Under what condition are they impermeable to salts?
How does ADH lead to water reabsorption in the DCT/CD?
How does aldosterone lead to sodium reabsorption in the DCT/CD?
How much of total Na+ reabsorption occurs in the DCT/CD? Is it more or less impactful on Na+ homeostasis than PT malabsorption?
What structures are included in the renal corpuscle?
Glomerulus
Bowman’s capsule
What equation can be used to represent excretion from the kidneys?
Excretion = Filtration - Reabsorption + Secretion
What percentage of nephrons are classified as cortical? Where are they located? What is the relative length of the loops of Henle?
What capillaries receive blood from the EGA in cortical nephrons?
What percentage of nephrons are classified as juxtamedullary? Where are they located? What is the relative length of the loops of Henle?
What capillaries receive blood from the EGA in juxtamedullary nephrons?
What are the three parts of the glomerular filtration apparatus (GFA)?
1) Fenestrated glomerular capillary
2) GBM
3) Podocytes with filtration slits
What is the purpose of the counter-current exchanger in the renal medulla?
Where are macula densa cells found?
DCT
Does maximally dilute urine require the presence of Aldosterone, ADH, both or neither?
Does maximally concentrated urine require the presence of Aldosterone, ADH, both or neither?
*With ADH, no aldosterone
Does urine with the same osmolality of body fluids require the presence of Aldosterone, ADH, both or neither?
What are the 3 unique cell types that compose the juxtaglomerular apparatus?
1) JG cells (granular cells)
2) Macula densa
3) Mesangial cells
What is the function of juxtaglomerular cells? What are the 3 situations that activate them?
What is the role of macula densa cells in the JG apparatus? What occurs when a drop in tubular fluid Na+ concentration is sensed?
Small tumors (less than 1.5cm diameter) found in the renal cortex, comprising branching, papillomatous structures with complex fronds would most likely represent what type of neoplasm?
Renal papillary adenoma
What type of renal neoplasm is present in 25-50% of patients with tuberous sclerosis?
Angiomyolipoma
An epithelial neoplasm comprised of large eosinophilic cells with small nuclei and large nucleoli; also presenting as a tan/brown tumor would most likely be classified as what type of neoplasm?
Oncocytoma
Tuberous sclerosis is caused by a loss-of-function mutation in which genes?
TSC1 or TSC2
What manifestations characterize tuberous sclerosis?
Lesions of the cerebral cortex that produce epilepsy and intellectual disability
What percentage of renal cancers are renal cell carcinomas?
85%
The VHL gene mutation is associated with what type of renal cell carcinoma?
Renal clear cell carcinoma
The MET gene mutation is associated with what type of renal cell carcinoma?
Renal papillary carcinoma
What cellular abnormalities can be found in renal chromophobe carcinoma ? What can it be difficult to distinguish from?
Prominant cell membranes and pale eosinophilic cytoplasm
*A halo around the nucleus is often seen
It can be difficult histologically to distinguish from oncocytoma
What percentage of renal clear cell carcinoma cases are familial? What percentage are sporadic?
Familial: 5%
Sporadic: 95%
At what systolic and diastolic values is a blood pressure classified as Stage 1 HTN? Is one measurement sufficient?
Each increment of ____ mmHg in SBP or ____ mmHg in DBP doubles the risk of death from stroke, heart or vascular disease.
What are the 6 broad causes of HTN?
What two criteria could classify hypertension as stage 1?
What two criteria could classify hypertension as stage 2?
What is essential hypertension?
Hypertension of no single, definable cause
AKA primary hypertension
What is secondary hypertension?
Hypertension with a known etiology (potentially reversible)
What is resistant hypertension?
What is malignant hypertension?
What is the main difference between hypertensive urgency and hypertensive emergency?
What is a better phrase than “hypertensive urgency”?
Severe uncontrolled hypertension
What immediate treatment steps are indicated for a hypertensive urgency (severe uncontrolled HTN)?
What immediate treatment steps are indicated for a hypertensive emergency?
What are the 5 most common causes of secondary hypertension?
What type of cells surround the glomerulus just outside of Bowman’s space?
Parietal cells
What are the four main compartments of the kidney to be considered in pathologies?
Glomeruli
Tubules
Interstitium
Vessels
What is a common mechanism of glomerular injury?
What are common mechanisms of vessel injury in the kidneys?
What are common mechanisms of tubular or interstitial injury in the kidneys?
What disease state is visible here?
End Stage Renal Disease
-sclerotic glomeruli
-poor tubule visualization
-lots of inflammatory cells
What are the different cells (labeled 1-4) in this electron microscope picture?
What are the different cells/structures/spaces (labeled 1-6) in this electron microscope picture?
What is the difference between primary and secondary glomerular disease? What are the two major manifestations of glomerular disease?
What is a simple definition of nephrotic syndrome? What are three notable clinical features?
Massive proteinuria
Edema
Foamy urine (due to protein)
What are two notable pathologies that patients with nephrotic syndrome have increased susceptibility to?
What is a simple definition of nephritic syndrome? What are 5 notable clinical features?
Hematuria (w/ casts)
Proteinuria
Dysmorphic RBCs
Azotemia (increased BUN)
Coke-colored urine
How do immune complexes activate the classical complement pathway?
What is the difference in location between sub-epithelial, sub-endothelial and mesangial immune complex deposition?
What type of immune complex deposition is occuring in this picture?
Subendothelial IC deposition
What type of immune complex deposition is occuring in this picture?
Subepithelial IC deposition
What are possible etiologies for granular-pattern inflammation (left) vs linear-pattern inflammation (right)?
What type of renal tumor is visible here?
Renal papillary adenoma
What type of renal tumor is visible here? How is it described?
Renal papillary adenoma
Well-circumscribed, greyish-white to yellow nodules
What renal tumor is visible here? What disease is associated with it in 25-50% of patients? What renal crisis are these patients suceptible to?
Angiomyolipoma
Tuberous sclerosis
Spontaneous retriperitoneal hemorrhage
What renal tumor is visible here? How is it described?
Well-circumscribed, mahogany brown-yellow
What is one difference that can be used to differentiate oncocytoma nad chromophobe RCC histologically?
Chromophobe RCC presents with “halos” around the nuclei of affected cells
What is Benign Nephrosclerosis?
Luminal narrowsing of arterioles/small arteries caused by hyalinization of walls (hyaline arteriosclerosis)
*grossly may appear leathery and granular
What kidney tumor is visible here? How is the appearance described?
Malignant nephrosclerosis
*The rupture of capillaries gives rise to petechiae that give the kidney a “flea-bitten” appearance
What are two notable microscopic findings for malignant nephrosclerosis?
What is the most common cause of renal artery stenosis?
What is the 2nd most common cause of renal artery stenosis? What are two important RF?
What is the main clinical impact of renal artery stenosis?
What are the expected clinical findings in benign nephrosclerosis? What are the expected clinical findings in maligant nephrosclerosis?
What subtype of renal cancer represents 70-80% of cancer findings?
Renal clear cell carcinoma
What type of renal pathology is visible here?
Renal clear cell carcinoma
Renal clear cell carcinoma has a tendency to invade into what vascular structure?
The renal vein
What percentage of renal cell carcinomas are sporadic?
95%
What gene inactivation is associated with the cases of renal cell caricinoma that are genetic?
Inactivation of the Von-Hippel-Lindau gene (VHL)
What notable pathology visible here is unique to the type of cancer occuring? What type of cancer is it?
“peri-nuclear halos”
Chromophobe carcinoma
Of renal clear cell carcinomas, renal papillary carcinoma and chromophobe carcinomas, which have the best prognosis?
Chromophobe carcinomas
What type of renal cancer can be seen here?
XP11 translocation renal cell carcinoma
What elements of the triphasic appearance (Wilm’s tumor) are located by the red and greens arrows, respectively, as well as the yellow circle?
RA: Stromal component
GA: Epithelial component
YC: Blastemic component
What is a unique feature of this particular sample of a Wilm’s tumor? What is the influence on the prognosis?
Anaplastic presentation
Worse prognosis for anaplastic presentation
What three notable syndromes carry an associated risk of Wilm’s tumor?
What effect can heavy menstruation have on urine protein readings?
Elevated urine protein readings due to difficulty in obtaining a clean-catch sample
What are 3 situations in which a false positive result for blood on urinalysis can be obtained?
1) Hemoglobin in urine (i.e. intravascular hemolysis)
2) Myoglobin in urine (rhabdomyolysis)
3) Semen in urine
Presence of what vitamin on some disticks can lead to false negative for hematuria?
Vitamin C (ascorbic acid)
In what two kidney diseases are white cell casts seen?
In what type of kidney diseases can fatty casts be seen?
With what kidney disease can waxy casts be seen?
In what kidney pathology can “muddy brown” casts be seen?
In what type of kidney pathology can hyaline casts be seen?
What are the five types of kidney stones pictured here?
What isthe Kidney Disease: Improving Global Outcomes (KDIGO) definition of acute renal failure?
What is oliguria?
Less than 500mL/day of urine output
What is anuria?
Urine output of less than 50mL/day
What is indicated by a FeNa of less than 1%? What is the formula for FeNa?
What acronym is used to indicate emergent need of dialysis?
pH persistantly below what level despite management is indicative for dialysis? Hyperkalemia above what level is indicative for dialysis?
What is the primary absorption site of magnesium in the nephron?
The TAL
How does hypomagnesemia affect potassium?
Magnesium blocks the ROMK channel, so hypomagnesemia can lead to worse potassium losses through ROMK
What is the difference in primary indication for loop diuretics vs thiazide diuretics?
Loop- diuresis for hypervolemia
Thiazide- HTN, nephrolithiasis
What is a potential treatment for a patient with normal kidney function with stage 2 hypertension?
Losartan + hydrochlorothiazide
What effect does aldosterone have on urinary excretion of potassium?
Aldosterone increaeses renal excretion of potassium
What should generally be given in orde to treat hypokalemia? What should be given if the patient is acidemic?
Potassium chloride is generally the best
If the patient is acidemic, give potassium citrate
What is the preferred treatment for hyperkalemia? What are next steps?
First step, IV calcium gluconate (stabilize myocardium)
Then insulin and glucose (also bicarbonate) given to push K+ into the cells
What are the two main actions of PTH?
What are the two main effects of calcitriol? How are these effects undone?
What is the overall effect of FGF23? What releases it?
FGF23 is released by osteoclasts and osteoblasts in response to calcitriol and high phosphate
It has a phosphaturic effect
What are the two main functions of calcitonin?
To reduce plasma calcium and phosphorous
Which diuretic increases urinary calcium?
Loop diuretics (also maybe CAIs)
Which diuretics increase plasma calcium?
Thiazide diuretics
Potassium sparing
Which diuretics increase urinary magnesium?
Thiazide diuretics
Does a patient with a an eGFR of 60 without other markers of kidney of kidne damage have CKD?
No!
What are typical differences in prior creatinine in AKI CKD?
What are main differences in kidney size in AKI vs CKD?
What are the main differences in exam findings and labs between AKI and CKD?
In proteinuric CKD, what medications may be used even though they can have a reductive effect on the GFR?
ACEi or ARBs
What transporter creates most of the gradiant driving bicarbonate reabsorption in the PCT?
the Na/K ATPase
Does ammonia or titratable acids have a greater capacity to bind acid in the renal tubules?
Ammonia; titratable acids can only accomodate a “fixed” amount, about 30mmol of acid excretion per day
Where is ammonia generated in the kidney?
the PCT
What effect does hypokalemia/hyperkalemia have on ammonia production?
Hypokalemia: Stimulates ammonia production
Hyperkalemia: Reduces ammonia production
