BIOM 4180 Lecture Notes - Lecture 2: Ablation, Sunburn, Antiarrhythmic Agent

• School: University of Guelph
• Department: Biomedical Sciences
• Course: BIOM 4180
• Professor: Glen Pyle

Document Summary

Lecture 2: action potentials: sinoatrial node, allows the heart to function independent of the brain (neural input) 60mv: na+ flows in at first when the cell is @-60mv because of funny current/hcn channel, hcn: hyperpolarization-activated cyclic nucleotide gated channel, positive change is flowing in, cell membrane potential becomes more positive. There are a lot of l-type ca++ channels, so the membrane potential increases very quickly. ), the k+ channels open to let k+ out of the cell: positive charge leaves the cell, membrane potential goes down. Less ca++ coming in, makes it harder to increase membrane potential and fire. Levels or hcn4 channels are the same: pregnant ladies are also at a higher risk of arrhythmia (irregular heart rate) If one part of the sa node has more hcn2, it might fire action potentials more often than the other parts: uncoordinated firing might lead to irregular heart beating, limits fibrillation entry to ventricles.