PSL301H1 Lecture Notes - Lecture 7: Pacemaker Potential, Endoplasmic Reticulum, Atrioventricular Node

• School: UTSG
• Department: Physiology
• Course: PSL301H1
• Professor: French, Gramolini, Richardson, Wong

Document Summary

Lecture 2: cardiovascular system cardiac action potential. In order to generate blood flow, there needs to be a generation of a pressure gradient: this is done with cardiac contraction, the heart is a simple pump with very small moving parts. Cardiac muscle cells: the bulk of the heart is composed of cardiac muscle cells (myocardium, contractile myocardial cells are striated muscle with contractile fibers organized into sarcomeres, cardiac muscles vs. skeletal muscles. Cardiac muscles are smaller and have a single nucleus per fiber. Myocardial muscle cells are branched and are attached to each other by specialized junctions known as intercalated disk. Desmosomes allow force to be transferred from cell to cell. Gap junctions provide electrical connection between cardiac muscle cells; allow electrical signals to spread rapidly from cell to cell, so that all the cells contract simultaneously. The t-tubules of myocardial cells are large and branch more. Mitochondria occupy one-third of cell volume of a contractile fiber.