CSB343H1 Lecture Notes - Lecture 4: Neuromuscular Junction, Efferent Nerve Fiber, Chemical Synapse
16 Jan 2019
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In neurons this is not necessarily true: allows for the fine-tuning of the muscle units. In cardiac muscle all the cells contract at the same time when an action potential is received. Inhibition prevents contraction form occurring: allows the cns to control muscle contraction, electrically isolated, muscle fibre is innervated by a single motor unit, no electrical conductivity between muscle fibers. Increased positive charge: activate voltage gated na channels to open, more na to rush in, ach is rapidly converted to choline and acetyl-cholinesterase, uptake back into the presynaptic terminal, this stops the signal propagation. If the membrane has reached threshold there will always be an epsp happening. Excitation-contraction coupling: accomplished by the interactions of the transverse tubules and the sarcoplasmic reticulum, depolarization travels down the t-tubule and hit the dhpr which are. Increase in ca in the cell leads to cross-bridge activation and excitation contraction coupling: force generation occurs, latent periods, action potential occurs when when the force occurs.
