ANSC 3080 Lecture Notes - Lecture 7: Tetanic Contraction, Tachycardia, Endoplasmic Reticulum

• School: University of Guelph
• Department: Animal Science
• Course: ANSC 3080
• Professor: Julie Kim

Document Summary

= allow ion to move freely from 1 cell to another electrical activity can pass from cell to cell. Myocardium composed of 2 types of muscle cells = contractile cells and autorhythmic cells. Contractile = 99% of cells, ap required for contraction. Autorhythmic = non-contractile, concentrated on specific regions, spontaneously generate ap. Gap junctions = water filled pores forming open connections (no neurotransmitter required) Sino-atrial node (where vena cava enters r atria) Also has autorhythmic ability but pace slower, so under sa control. Gateway for electrical conduction between atria and ventricles. Help to quickly propagate electrical activity from the av node to rest of ventricles. Problems with conduction = abnormal rhythm = arrhythmia. Sa node self excitation (generation of aps: aps propagate through atria = atrial contraction, av node activated by ap wave, transmit electrical activity to bundle of his and purkinje fibers. Electrical activity propagate through ventricles = ventricular contraction.