BIOL 1119 Lecture Notes - Lecture 3: Chronotropic, Hypercalcaemia, Hyperkalemia

• School: Northeastern University
• Department: Biology
• Course: BIOL 1119
• Professor: Christopher Richardson

Document Summary

Chronotropic chemicals: affect heart rate, blood born norepinephrine (ne) and epinephrine (catecholamines) If rise in extracelluar k+ is slow, then keeps membrane voltage elevated: excessive k+ levels in body tissues, myocardium less excitable, hr slow and irregular. If rise in extracelluar k+ is fast, then membrane voltage rises closer to threshold: myocardium is more excitable; more likely to have action potential which disrupts regular rhythm, hr irregular. Hypokalemia: extracellular potassium deficiency, cells hyperpolarized, harder to stimulate heart cells, electrolytes: calcium.