NEPHRON ARCHITECTURE
This nephron segment is present in both cortex and medulla and plays a key role in establishing the corticomedullary osmotic gradient.
What is the loop of Henle?
This layer of the filtration barrier is responsible for size selectivity due to its collagen IV network.
What is the glomerular basement membrane?
This Starling force is the primary driving pressure for filtration in the glomerulus.
What is glomerular hydrostatic pressure?
This specialized DCT structure senses tubular NaCl concentration.
What is the macula densa?
Approximately what percentage of filtered sodium and water is reabsorbed in the proximal tubule?
1. 20% 2. 65% 3. 90% 4. 5%
What is approximately 65%?
These structures appear granular on histology due to the presence of renal corpuscles.
What is the renal cortex?
Damage to this component of the filtration barrier most directly leads to proteinuria.
What are podocytes (slit diaphragms)?
Selective afferent arteriole vasoconstriction causes what change in GFR?
What is decreased GFR?
These modified smooth muscle cells release renin in response to hypotension.
What are juxtaglomerular (granular) cells?
Glucose reabsorption in the proximal tubule relies on this apical transporter.
What is SGLT-2?
You are examining a histologic section with simple squamous epithelium, flattened nuclei bulging into the lumen, and no brush border. Identify the nephron segment.
What is the thin limb of the loop of Henle?
A dog presents with hematuria but no proteinuria. Which filtration barrier layer is most likely compromised?
What is the fenestrated endothelium?
Moderate efferent arteriole vasoconstriction initially has what effect on GFR, and why?
What is increased GFR due to increased glomerular hydrostatic pressure despite reduced outflow?
Low NaCl delivery to the macula densa triggers what two immediate renal effects?
What are afferent arteriole dilation and renin release?
Why does glucosuria occur in Fanconi syndrome despite normal blood glucose?
What is proximal tubular transporter failure exceeding reabsorptive capacity?
This nephron type is primarily responsible for the kidney’s ability to produce concentrated urine and is closely associated with the vasa recta.
What is the juxtamedullary nephron?
Explain why albumin is normally excluded from the filtrate despite being smaller than some filtered solutes.
What is charge selectivity of the filtration barrier (negative charge repulsion)?
Severe efferent arteriole vasoconstriction paradoxically decreases GFR. What Starling force explains this?
What is increased glomerular colloid osmotic pressure?
Explain how ACE inhibitors reduce both preload and afterload.
What is decreased angiotensin II leading to vasodilation and reduced aldosterone-mediated volume retention?
Which electrolyte’s reabsorption in the proximal tubule is inhibited by parathyroid hormone, leading to increased urinary loss?
What is phosphate?
A nephron segment shows cuboidal cells, no brush border, a wide lumen, and is hormonally responsive to aldosterone and ADH. Where are you?
What is the distal convoluted tubule?
A disease selectively thickens the glomerular basement membrane without affecting podocytes. Predict the effect on GFR and explain why.
What is decreased GFR due to increased filtration resistance and reduced permeability?
An animal develops a ureteral obstruction from a urolith. Which Starling force increases and leads to a decrease in GFR?
What is increased capsular hydrostatic pressure?
A cat with chronic kidney disease has inappropriate RAAS activation. Predict the long-term effect on glomerular structure.
What is glomerular hypertension
A dog has hypophosphatemia with normal GFR. Which hormone is responsible and how does it act at the proximal tubule?
What is PTH decreasing sodium-phosphate cotransporter expression and increasing phosphate excretion?