A & Pee
This functional unit of the kidney contains a cortex housing the glomeruli and an inner medulla made up of renal pyramids.
What is the nephron?
Efferent vasodilation will have what effect on renal blood flow and GFR
Increase in renal blood flow (opening up of traffic jam) but decrease in GFR because it reduces the glomerular hydrostatic pressure
Patients with CKD are particularly susceptible to which electrolyte abnormality, resulting in edema or dehydration
What is sodium?
Nephrotic syndromes are hallmarked by proteinuria (>3.5 g/day) resulting in a frothy appearing urine, while nephritic syndrome are characterized by urine with this appearance
Blood, resulting from the loss of red blood cells
Nephritic syndrome also has proteinuria but to a lesser extent (<2 g/day)
Your patient presents with presents with an abrupt onset of fever, chills, and costovertebral angle tenderness, as well as leukoesterase in the urine. This treatment would be the most helpful at targeting the cause of the renal injury
What are antibiotics?
Signs/symptoms point to pyelonephritis, or infection of the kidney parenchyma and renal pelvis
This is the primary site of nutrient reabosorption, including glucose
What is the proximal convoluted tubule?
65-80% of all reabsortive and secretary processes take place in the proximal tubule
Mild stenosis of the efferent arteriole will have this effect on GFR
What is improvement/increased?
Mild efferent constriction will decrease renal blood flow (like a traffic jam), but will increase GFR. When the efferent constriction becomes severe, GFR will decrease
These three biomarkers will decrease in CKD (or just name one)
What are pH (acidosis), calcium, and bicarb?
Meanwhile, potassium, phosphorus, BUN, creatinine (and hydrogen ions) will increase in CKD
This disease (a leading cause of CKD in the US) is the result of sclerotic changes resulting in collagen deposition and inability to augment blood flow to the nephron, ultimately resulting in renal atrophy
What is hypertensive nephrosclerosis?
Not a nephrotic disease but worsens existing nephrotic diseases
Your patient was found down after being on the ground for two days. Labs are significant for AKI with cola colored urine. You suspect this, which is the most common cause of AKI in hospitalized adults
What is acute tubular necrosis/acute tubular injury?
Possible causes of ATN are ischemia, nephrotoxins, infection, and intratubular obstruction from things such as myoglobin
ADH binds to vasopressin receptors here and leads to the creation of aquaporin channels to reabsorb water
What is the collecting duct?
These cells perform autogenic regulation of kidneys by monitoring of sodium filtrate content and modifying afferent arteriole and renin release to maintain a stable GFR in normotension
What are macula densa cells?
Decreased sodium delivery to the DCT results in vasodilation of the afferent arteriole (to increase RBF and increase GFR) and renin release via juxtaglomerular cells
A patient with severe hypotension with shock will most likely have this type of AKI
What is prerenal?
Prerenal AKIs are due to insufficient blood flow, while intrarenal AKIs (such as ATN) are due to damage to the nephron, and post renal AKIs (such as from bladder obstruction) result from some sort of bilateral obstruction
Your patient is presenting both with bloody and frothy urine, as well as edema and hypertension. This lab will be the most helpful in confirming your diagnosis
What is ANA, which would be present in Systemic Lupus Erythematosus Glomerulonephritis?
This type of renal tubular acidosis will result in hyperkalemia
What is type 4 from aldosterone deficiency, which impairs sodium reabsorption and potassium secretion
This is the site of action of aldosterone, and also where calcium is reabsorbed
What is the distal convoluted tubule?
In the case of severe hypotension, activation of the SNS will adjust renal blood flow by doing this
What is constricting the afferent arteriole?
SNS activation constricts the afferent arteriole resulting decreased RBF, decreased GFR, and increased renin
Your patient with CKD is noted to have hypocalcemia, hyperparathyroidism, and skeletal buffering of acidosis, all of which can lead to what complication?
What is renal osteodystrophy?
Can lead to bone tenderness, fractures, and muscle weakness
*Of note elevated PTH can be the earliest sign of CKD
A child presents with sore throat, cola-colored urine, and periorbital edema. You are suspicious for this nephritic disease, which is the result of antibody deposits into the glomerulus
What is acute post infectious glomerulonephritis?
This results from group A strep infection, antistreptococcal antibody (ASO) titer will be elevated
Usually nephrotic diseases are associated with edema, but kids are weird
Uric acid stones are associated with gout and acidic urine, while struvite stones form in alkaline urine and in the presence of what
What is bacteria (that possess an enzyme called urease)?
The two other types of stones are calcium (2/2 immobilization, hyperparathyroidism, bone disease, etc) and cystine (childhood caliculi 2/2 genetic defect)
This specific structure monitors sodium chloride concentration in the filtrate in the distal convoluted tubule to help regulate renin release
What is the juxtaglomerular apparatus?
Macula densa monitors sodium, juxtaglomerular cells contain renin
This mechanism of control for renal blood flow (involving efferent vasoconstriction) activates with mild reductions in blood pressure
What is the RAAS system?
Slight drop in MAP 70-80mmHg activates RAAS, resulting in mild efferent vasoconstriction which decreases blood renal blood flow slightly but will increase GFR
Your patient who has been in the ICU with a foley suddenly develops oliguria. You flush the foley and he dumps 1000mL urine. He continues to void painlessly but the next morning his Cr is doubled, which means his GFR has fallen by half. What type of AKI do you suspect?
What is postrenal AKI?
Bilateral obstruction will result in post renal AKI. No pain means no intrarenal cause like UTI or pyelonephritis. Cr rise is delayed about 24 hours so may not see rise until after condition resolved
This disease is the result of defective synthesis of the glomerular basement membrane and mesangial matrix, resulting in nodular deposits that create enlarged capillary pores that lead to proteinuria and eventually nephron destruction
What is diabetic nephropoathy?
This is a nephrotic disease
Type 1 renal tubular acidosis results in significant metabolic acidosis and urine pH >5.5 due to a defect in hydrogen ion secretion where?
What is the distal convoluted tubule?
Conversely, type 2 RTA affects HCO3 reabsorption in the proximal tubule which results in less severe acidosis (because the DCT can compensate) with urine pH <5.5, and can be a part of PCT defects known as "Fanconi syndrome"