Fundamentals - Of Medical Physiology Link

As E-1173 made its return journey, now a tired, deoxygenated blue, it entered the renal circulation. The kidney was a master of . Blood pressure forced plasma through the glomerulus, but E-1173 was too large to pass. It tumbled through the vasa recta, past the loop of Henle, where countercurrent multiplication was busy concentrating urine. Suddenly, the vessel ruptured. A microscopic tear in the arteriole wall.

But a crisis loomed.

In the beginning, there was a void. Not an empty one, but a bustling, hypoxic darkness deep within the spongy red marrow of a human femur. Here, in the hematopoietic niche, a humble hematopoietic stem cell received a signal: a whisper of the cytokine erythropoietin, released by the kidneys because the blood’s oxygen levels had dipped slightly below a set point. fundamentals of medical physiology