Physiology 1021 Chapter Notes - Chapter 5: Phosphate, Motor Unit, Neuromuscular Junction

• School: Western University
• Department: Physiology
• Course: Physiology 1021
• Professor: Tom Stavraky

Document Summary

Muscles perform three principal functions: movement, heat production, body support and posture. A whole look at the structure of muscle. Whole muscle, is composed of groups of fasciculi surrounded by a white connective tissue called perimysium each fascicle is made up of bundles of muscle cells (also called muscle fibers) Within each cell there are cylindrical bundles of myofibrils composed of two types of myofilaments. Structure of a muscle cell: which are the actual contractile elements of the cell. T tubules conduct the action potential deep into the cell where the contractile proteins are located. Within the muscle cell are long cylindrical myofibrils that contain the contractile proteins of the muscle the thin and thick myofilaments. Myofibrils are surrounded by the sarcoplasmic reticulum (sr) When ca++ bind to the troponin c unit, the tropomyosin is pulled off the myosin binding sites by the troponin. Many myosin molecules are arranged to form one thick filament.