Neuron Structure

Neuron Function

Neurons are located in the brain and transmit and receive neurotransmitters, which carry information between brain cells and can function as sensory, motor, or interneuron neurons.

How does an action potential move along the neuron fibre?

Positively charged ions go into the cell body as a cell depolarizes. By passing through neurotransmitter-activated channels, these ions decrease the membrane potential until it approaches zero. Because of this process, the cell becomes less polar, which lets sodium ions enter the negatively charged axon and depolarize the axon around it. The action potential causes the cell to shift past equilibrium and receive a positive charge. While hyperpolarization causes the cell to become more negative than its normal resting membrane potential, repolarization brings the cell to its resting potential. When potassium channels close, the sodium-potassium pump works to return the body to its resting condition.

Synapse Structure

Synapse Function

Synapses connect neurons and help transmit information from one neuron to another.

How is a signal sent from the axon of the sending neuron to the dendrite of the receiving neuron?

The process is called neurotransmission. The transfer of information from one neuron to another takes place through the release of chemical substances – neurotransmitters – into the space between the axon and the dendrites.

How does the receiving neuron “determine” whether or not to send its own action potential?

The receiving neuron adds up the signals it receives to decide whether to send its own action potential. The neuron will fire an action potential if the combined signals reach above a particular threshold. The neurons stay at rest if they don’t.