PHYS20008 Lecture Notes - Lecture 12: Cardiac Muscle, Skeletal Muscle, Intercalated Disc

• School: University of Melbourne
• Department: Physiology
• Course: PHYS20008
• Professor: Charles Sevigny

Document Summary

Skeletal muscle vs cardiac muscle vs smooth muscle: * skeletal muscle & cardiac muscle are both striated (striped in appearance- due to thick and thin filaments are overlapping in the same direction) *smooth muscle is unstriated (filaments are arranged like cardiac & skeletal muscle) * skeletal muscle is voluntary, whereas cardiac and smooth muscle are under involuntary control. * cardiac muscle is located in the heart. * cardiac muscle unlike skeletal muscle is not individually innervated (all skeletal muscle fibres have an alpha motor neuron going to them that initiates an action potential and causes contraction). * there are pacemaker cells that initiate action potentials, and these action potentials once initiated spread through the rest of the heart from cell to cell to cell. How it spreads from one cell to another is through intercalated disks and this enables an action potential to spread from one cell to the next cell.