The human nervous system is a complex collection of nerves and neurons, which work together to receive or transmit signals throughout our entire body. Neurons communicate to other neurons, or other cells within the body, through electrical impulses known as action potentials. These action potentials trigger a release of neurotransmitter from the neuron, which then diffuse across what is known as a synapse, before binding to and affecting the postsynaptic neuron or cell. These neurons and electrical impulses can be involved in afferent pathways, which receive an external stimulus and bring information about it to the brain to be processed. They can also be involved in efferent pathways as well, which send a signal from the brain to a specific part of the body in order to carry out an effect or task.
Sensory neurons are involved within afferent pathways. Gustatory receptors can receive an external chemical stimulus within our mouth which our brain will process as sweet, or salty, or sour. Photoreceptors can take in light which is then processed into our vision and what we see. Hair receptors located within the vestibule of our ear can detect changes which eventually allow us to keep our balance when walking or moving.
With all of these different functions in the nervous system it can make you wonder, what would life be without these neurons and electrical impulses? Without nociceptors one could not feel pain. Without olfactory receptors one would not be able to smell. A neuromuscular junction is a neuron which synapses onto a specific muscle, allowing it to move and contract. Without these, we would not be able to move. Our entire life, including what we perceive around us and also how we respond to it, is controlled and dictated by the electrical impulses that our neurons send to our brain. Without these, we would perceive nothing. We would be able to do nothing. Without neurons, there would be no spark in life at all.
Posted by Michael Magnant (1)