HLSC 1200U Lecture Notes - Lecture 14: Cardiac Muscle, Skeletal Muscle, Syncytium
Document Summary
Smooth muscles are involuntary, exist in the stomach, blood vessels, small intestines. Cardiac muscles are only found in the heart, involuntary, responds to stressors. Syncytium: conduct electrical activity from one cell to the other without having individual nerves intervene. Allows for quick signals to contract muscles. Cardiac muscles are involuntary; thus the stimulus exists within the cardiac muscle itself. Skeletal muscles, in contrast, require an action potential/trigger from an external source. Both smooth and skeletal muscles contain thick and thin filaments. Sarcomere is essentially a segment of micro fibrils between two dead disks. A contractile muscle unit of the muscle fibers. The two disks anchor the two halves of the thin filaments, and provide structural support so that the thin filaments do not fall apart. T tubules are important because the voltage changes and as a result, calcium is released. A neuromuscular junction is where there is a meeting or a collection, meeting place of the nerve and the muscle.
