During neural signaling in mammals, a neuron resting at appr…

During neural signaling in mammals, a neuron resting at approximately –70 mV begins to depolarize due to graded potentials from dendrites. Once the membrane reaches about –55 mV at the axon hillock, a rapid spike to +30 mV occurs. This explosive event is best described as:

A sensory neuron in a mammal receives input from multiple up…

A sensory neuron in a mammal receives input from multiple upstream neurons before sending a signal toward the spinal cord. Which structural region of the neuron is primarily responsible for increasing surface area to receive these incoming signals and integrate graded potentials?