Brain Bee Study Guide Link

The muscle fiber fires an action potential. on the T-tubule sense the voltage change and mechanically open ryanodine receptors (RyRs) on the sarcoplasmic reticulum. Calcium floods the cytosol.

You are about to initiate movement. The EPSP travels down your dendrites, summing at the axon hillock — your decision zone. Here, voltage-gated sodium channels wait. The membrane potential crosses threshold (-55 mV from resting -70 mV). Bang. brain bee study guide

One day, you receive an urgent message from the . A structure called the subthalamic nucleus has fired a burst of glutamate (excitatory) at your rival, an inhibitory neuron in the globus pallidus internus (GPi) . That GPi neuron normally clamps down on the thalamus like a hand squeezing a hose. But now, GPi is silenced. The muscle fiber fires an action potential

The hose is open.

At the NMJ, the enzyme — sitting on the basal lamina — rapidly cleaves ACh into acetate and choline. Choline is taken back up into the LMN via the choline transporter (CHT1) , then reused. You are about to initiate movement