In this episode of Paging Dr. Samir, we take the next step from transport and gradients into electrophysiology—the rules that determine when cells fire, when they stay silent, and when electrical systems fail without warning. Dr. Samir breaks down resting membrane potential, thresholds, action potentials, repolarization, and refractory periods as clinical decision points rather than abstract waveforms.

Using real bedside scenarios including hyperkalemia, ischemia, wide-complex tachycardia, and sudden collapse, this episode explains why arrhythmias are usually symptoms of an unstable electrical substrate, not the primary problem. You’ll learn how electrolyte abnormalities, ischemia, and drugs alter ion channel availability, slow conduction, promote reentry, and create lethal instability.

This episode reframes electrophysiology as timing, recovery, and control—showing why calcium stabilizes membranes, why sodium channels matter more than heart rate, and why treating rhythm without fixing the substrate can make things worse. If electrophysiology has ever felt intimidating, this episode makes it predictable, usable, and clinically relevant.

Clinical electrophysiology explained through resting membrane potential, action potentials, ion channels, electrolytes, arrhythmias, and real bedside decision-making.

In this episode of Paging Dr. Samir, we move from homeostasis down to the cellular level to explain why organ failure always starts with membrane failure. Dr. Samir characterizes cell membranes as control interfaces, not anatomical diagrams, and explains how transporters, pumps, and gradients drive excitability, fluid shifts, and electrical stability.

Using real clinical examples like hyperkalemia, arrhythmias, edema, and altered mental status, this episode connects electrolyte abnormalities to membrane potential and explains why treatment priorities focus on stabilizing membranes before chasing lab values. Passive transport, active transport, the sodium-potassium pump, calcium handling, and membrane potentials are all integrated into a practical, bedside-ready framework.

If physiology has ever felt fragmented or memorization-heavy, this episode shows how transport and gradients unify everything from EKG changes to emergency management. This is physiology intended for use, not memorization.

Medical physiology explained through cell membranes, electrolytes, and transport. Learn how sodium, potassium, calcium, and membrane potentials drive EKG changes, arrhythmias, edema, and clinical decision-making in real patient cases.

Welcome to the first episode of Paging Dr. Samir, where physiology stops being abstract and starts making clinical sense.

In this episode, Dr. Samir breaks down the single most important concept in all of medicine: homeostasis. Not anatomy. Not pharmacology. Homeostasis — the body’s relentless effort to maintain internal stability in a constantly changing world.

This isn’t a lecture full of slides or memorization. It’s clinical reasoning you can carry with you — on rounds, in the ICU, during exams, or in the middle of a long shift when things start to unravel.

🔍 In this episode, you’ll learn:

• What homeostasis actually means (and why “stable” doesn’t mean static)
• Why small lab changes can have massive cellular consequences
• How compensation hides disease — until it suddenly doesn’t
• The difference between negative and positive feedback loops
• Why does collapse look sudden but is never truly abrupt
• How to diagnose physiological failures by identifying broken feedback loops
• The roles of the nervous system, endocrine system, and local control
• Why do set points shift during fever, stress, and chronic disease
• A real clinical walkthrough of heat stroke as runaway physiology
• How to think like a clinician who anticipates failure instead of reacting to it

💡 Key takeaway:

Disease isn’t just abnormal numbers — it’s the loss of regulation. When the body can still compensate, physiology hides pathology. When it can’t, deterioration accelerates.

This episode lays the foundation for everything that follows — cardiology, renal physiology, endocrinology, critical care, and beyond. Once you learn to see medicine as a system of control and feedback, the noise fades, and the signal becomes clear.

🎧 Whether you’re a medical student, resident, nurse, perfusionist, or seasoned clinician, this is physiology designed to stick.

👉 Next episode: We dive down to the cellular level — membranes, ion gradients, and why sodium insists on coming in while potassium keeps trying to leave.

Stay curious. Stay critical. Stay caffeinated.

And, as always… keep things boring.