BIOL 225- Final Exam Guide - Comprehensive Notes for the exam ( 146 pages long!)

• School: Concordia University
• Department: Biology
• Course: BIOL 225
• Professor: Ian Ferguson

Document Summary

If the depolarization is great enough, nearby sodium gates open, allows more sodium to diffuse in cell = more depolarization = loop. If the depolarization passes the threshold, all sodium gates open. Inside of the neuron briefly becomes positively charged, which will open potassium gates and close sodium gates: potassium channel (ungated & gated): potassium diffuses out, making the inside of the neuron negative again. A(cid:272)tio(cid:374) pote(cid:374)tials a(cid:396)e (cid:858)all o(cid:396) (cid:374)othi(cid:374)g(cid:859) (cid:374)o su(cid:272)h thi(cid:374)gs as st(cid:396)o(cid:374)g o(cid:396) (cid:449)eak a(cid:272)tio(cid:374) pote(cid:374)tial. F(cid:396)e(cid:395)ue(cid:374)(cid:272)y of action potentials may reflect strength of signal. Last a few milliseconds and is followed by a short refractory period. The sodium gates remain inactivated for a few milliseconds, preventing the initiation of further graded or action potentials. It is impossible to create action potential during refractory period (starts as soon as sodium gates shut). Neuron: most cytoplasm found in cell body, dendrites are extensions of cell.