BPK 105 Lecture 3: BPK105 Module 3 Review Questions

• School: Simon Fraser University
• Department: Biomedical Physio & Kines
• Course: BPK 105
• Professor: Kelly Anthony

Document Summary

Na+ channels and some, but not all, k+ diffuses down its concentration gradient through the open k+ channels, making the inside of the cell membrane negatively charged compared to the outside. Describe an action potential (depolarization and repolarization) following stimulation of a muscle cell. Include the movement of ions and charge across the membrane, the state of ion channels (open or closed), and concentration and electrical gradients that exist. The change between depolarization and repolarization is action potential. Describe the functional steps that occur at the neuromuscular junction. Begin with motor neuron stimulation and end with muscle action potential. Describe what would happen if the receptor sites for acetylcholine were blocked by a poison such as curare: when an action potiental reaches the presynaptic terminal, it causes ca 2+ channels to open. Calcium ions enter the presynaptic terminal and cause several synaptic vesicles to release acetylcholine into the synaptic cleft by exocytosis.