If an already positive membrane potential becomes more positive, it is becoming hyperpolarized because the electrical difference between the inside and outside of the cell is getting larger. On the other hand, a stimulus that moves the potential difference closer to 0 is depolarizing because it is decreasing the difference in electrical potential between the inside and outside of the cell.

Myelin helps to increase resistance along the axon, which helps to propagate the action potential along the axon.

In order to have an action potential, you must have a depolarization. Na channels must close before K channels open

The action potential of a neuron is generate at the axon hillock and is propagated down the axon and to the terminal branches where it will synapse with the dendrites of the next neuron.

The influx of positive sodium ions into the neuron is known as depolarization. This is the loss of negative charge that occurs when positive sodium passes through the neural membrane and enters the neuron.

Depolarization is when the neuron becomes more positive by gaining positively charged ions, specifically sodium ions. During depolarization the sodium ion channels open and sodium ions enter the neuron, reducing the membrane potential to roughly +35 mV.

There are three possible neural cell structures: unipolar, bipolar, and multipolar. Bipolar neurons have only two extensions coming off of the cell body, typically the dendrite extension and the axon extension. Although there are only two extensions coming off of the neuron, it is still capable of interacting with many other neurons due to subsequent branching beyond the junction with the cell body.

Neurons are the cells that make up the nervous system. Neurons are large, permanent cells that do not divide during adulthood and spend most of their lives in the G0 phase of the cell cycle. If part of a neuron is damaged, it undergoes Wallerian degeneration, meaning that the neuron degenerates distal to the injury, and does not undergo reactive gliosis in response to injury. Astrocytes, a type of glial cell, do this.

A peripheral nerve is composed of three layers: the endoneurium (inner layer around a single nerve fiber), perineurium (middle layer that surrounds a fascicle of nerve fibers), and the epineurium (dense outer layer that surrounds an entire nerve).

Monosynaptic reflexes means that the afferent neuron directly stimulates an efferent neuron, which directly stimulates a muscle to contract. This means that the information never interfaces with the brain to process. The knee-jerk reflex is known as a monosynaptic reflex because only one neural synapse is involved in the reaction.