"The excitement didn't stay on the surface. It ran down secret tunnels—the T-tubules—deep into the heart of the cell, to a place called the Sarcoplasmic Reticulum, a great underground reservoir of calcium. The action potential knocked on a door. 'Open up,' it said. 'The King commands movement.'"
He smiled. "Alright, Dr. Pal," he whispered to the silent room. "One more story." gk pal physiology
Rohan was a good student. He had cruised through high school on a wave of effortless memory. But physiology, as GK Pal presented it, was not a subject to be memorized; it was a labyrinth to be survived. It didn't just ask what the resting membrane potential was. It demanded you derive the Nernst equation, curse the Goldman-Hodgkin-Katz constant field equation, and then weep over the role of the Na+/K+ ATPase, which the author affectionately (and ominously) called the "sodium-potassium pump." "The excitement didn't stay on the surface
"Sir," he said, using the honorific carefully, "if calcium release is normal but cross-bridge cycling is reduced, it suggests a defect in the myosin ATPase enzyme. The myosin head can bind to actin, but it cannot hydrolyze ATP to release and re-cock. It's a rigor state, but incomplete. Possibly a congenital myopathy or a metabolic issue with energy utilization." 'Open up,' it said
"Rohan," she said, eyes gleaming behind her spectacles. "A patient presents with muscle weakness that worsens with repetitive use. Their calcium release is normal, but the number of cross-bridge cycles is diminished. Where is the lesion? From GK Pal, chapter on Muscle Physiology."