BIOL273L Study Guide - Final Guide: Alpha Motor Neuron, Intrafusal Muscle Fiber, Extrafusal Muscle Fiber

• School: University of Waterloo
• Department: Biology
• Course: BIOL273L
• Professor: Bruce Wolff

Document Summary

Nerve cell job to sustain a difference in electrical charges between the cytoplasm and the surrounding extracellular fluid. Resting membrane potential is due to the cell being more permeable to certain ions that others. K+ are high inside, and na+ are higher outside. Na cannot diffuse in, but k can, creating a positive change on the outside surface of the cell = rmp. A charge difference can travel as a wave to the cell surface as a graded potential or action potential. This enables the neurons to transmit sensory info to the sc and brain and send signals to effector organs. Ussing chamber permeable to na and k, impermeable to cl and i. cations pass through the artificial membrane down their concentration gradient difference in charge. Activity coefficient = measure of how independently ions behave when dissolved. Small at low concentrations and high at high conc.