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- ☕️ Which of the following changes is most likely to occur first in the renal tubules during the ischemic phase?
☕️ Which of the following changes is most likely to occur first in the renal tubules during the ischemic phase?
Morning Quiz 110 ☕️
Dr. Shoaib Ahmad Baig
March 10, 2025
PS… Sorry for the delay, but as per overwhelming request we have added a new quiz feature called- Rapid Recall Review 🧠💨 in the end of this newsletter.
After reading, make sure to give this quiz to challenge yourself and stay ahead of the game!
Morning Quiz ☕️
Scientists are investigating how acute kidney injury (AKI) develops during septic shock.
In an experimental setup, they reduce renal perfusion pressure in mice to study the effects on renal tubular function and structure.
The pressure is lowered until the tubules show signs of dysfunction caused by mild cellular ischemia. Function is restored within a few hours after blood flow is reintroduced.
Question:
Which of the following changes is most likely to occur first in the renal tubules during the ischemic phase?
A. Activation of cytoplasmic caspases
B. Damage to the tubular basement membrane
C. Loss of epithelial cell polarity
D. Necrosis and sloughing of epithelial cells
Correct Answer 🎯: C. Loss of epithelial cell polarity
⚙️
Septic Shock
⬇
Systemic Inflammatory Response (cytokines ↑, vasodilation ↑)
( Imagine a dam breaking, flooding the body with inflammatory signals 🌊)
⬇
Hypotension (↓ systemic perfusion pressure)
( The heart’s pump weakens, and blood pressure drops ⬇ )
⬇
↓ Renal Perfusion Pressure (kidneys are starved of blood flow)
⬇
↓ Oxygen Delivery to Renal Tubules (ischemia begins)
⬇
↓ ATP Production (no oxygen for energy)
⬇
Switch to Anaerobic Metabolism (lactic acid builds up)
The cell starts fermenting like a backup generator, but it’s inefficient and toxic ☣.
⬇
Dysfunction of Na+/K+ ATPase Pump (ATP-dependent ion transport fails)
(The cell’s gatekeeper collapses 🚪)
⬇
Loss of Epithelial Cell Polarity (apical-basolateral organization disrupted)
( The cell’s “traffic system” goes haywire 🚦)
⬇
Mislocalization of Membrane Proteins (e.g., Na+/K+ ATPase moves to the wrong side)
( Imagine a delivery truck dropping packages in the wrong neighborhood 🚚 )
⬇
Impaired Tubular Reabsorption and Secretion (solute and water transport fails)
⬇
Tubular Dysfunction (earliest clinical manifestation of ischemia)
Differential Table ⚖️
Differential ⚖️ | Mechanism ⚙️ | Why Incorrect? 🔴 |
|---|---|---|
Activation of Cytoplasmic Caspases | Ischemia → Prolonged ATP depletion → Mitochondrial damage → Caspase activation → Apoptosis | Apoptosis is a late event; it requires prolonged ischemia and significant cellular damage. |
Damage to Tubular Basement Membrane | Ischemia → Inflammatory injury → Protease activation → Basement membrane degradation | Basement membrane damage is a late structural change, not an early functional change. |
Necrosis and Sloughing of Epithelial Cells | Severe ischemia → ATP depletion → Membrane rupture → Necrosis → Sloughing | Necrosis is a late event, occurring only after severe and prolonged ischemia. |
Practice Questions ⏳️
Most Importantly Solve UWorld Questions with IDs:
106935, 19292
Stay Hungry, Stay Curious!
Your Brother in This Struggle
Dr. Shoaib Ahmad
