Physiology 2130 Lecture Notes - Lecture 5: Endoplasmic Reticulum, Myelin, Myosin Head

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: Christine Bell

Document Summary

A muscle cell is multi-nucleated: during development, cells fused together to make this cell. Transverse tubules: carry the action potential from the information passed from the nerve through ach to muscle itself. Ap travels down transverse tubules and activates/excites sarcoplasmic reticulum. Sr: network of fibers that sit on top of myofibrils. Myofibrils: made of thick and thin myofibrils. Axon of a motor nerve with myelin sheath and the terminal bouton: spaces between the myelin sheath: nodes of ranvier. Conducting the ap down the axon to the terminal bouton. Voltage/change in membrane potential in the terminal bouton triggers calcium channels. Calcium floods into the terminal bouton, signaling the synaptic vesicles to release their content into the synaptic cleft. Vesicles undergo exocytosis: requires atp coordinated by many proteins, complex. First usage of atp in the energy coupling process: fuse with presynaptic membrane and dump ach into syntpatic cleft.