BIOLOGY 152 Lecture Notes - Membrane Potential, Voltmeter, Resting Potential
Document Summary
Break the problem down: body detects stimulus (light, sound, touch, chemical, temperature, etc. , sensory neuron translates this to something a cell would understand (a chemical/electrical signal, sends signal to central nervous system (cns) 4: cns directs this modified signal through motor neurons to muscle cells, to endocrine cells (to interneurons are used to filter, magnify, interpret, or ignore signal make hormones), etc. At axon terminus, it jumps to next cell. Axon membrane at rest has a negative membrane potential (-70) Voltmeter used to measure difference in charge between inside/outside of cell to determine membrane potential dif. is maintained by na+/k pump for every three na+ that leave cell, 5 k enter cell. Na+ gate opens when membrane potential > -50 mv. Def: graded potential anywhere below -50 mv (& not at resting potential) =action potential membrane repolarizes when k+ gates open.