IMED1004 Lecture Notes - Lecture 14: Hyperkalemia, Cardiac Arrhythmia, Neuromuscular Junction
17 Sep 2018
School
Department
Course
Professor
Document Summary
Essential elements i: know that na+ and k+ are major solutes of the ecf and the cytosol, and their concentration is maintained by the na+/k+ atpase. [solutes]outside: total [solutes]outside increase, water moves in, lower [solutes]inside. Sodium and potassium ions are ubiquitous solutes of the cytosol and extracellular fluid: 25l m u i l e h t o d n e y r a l l i p a. Na+ and k+ are pumped across the cellular membrane to maintain the osmolality of the cells and of the extracellular fluid. The na+/k+ atpase is a ubiquitous pump involved in this process. It maintains the osmolarity and the resting potential of the cell. The pumping of na+ and k+ also forms concentration gradients. These concentration gradients facilitate a range of cellular functions, including: transport of other solutes across the membrane, propagation of action potentials (cell signalling) Passive transport: no energy required- movement down concentration gradient (channels, symporters, antiporters)
