Neurons And How They Work In Our Brain
Neurons are the basic and operative units of our nervous system. They have three parts: the soma or cell body, the dendrites, and the axon. The soma is the centre of the neuron. Its shape is variable and energy for the functioning of the neuron is produced in it. It has a central nucleus with one or two prominent nucleoli and cytoplasm rich in organelles, among which Nissl corpuscles stand out. Dendrites are extensions that leave different parts of the soma and have the function of receiving impulses from other neurons and sending them to the soma.
Each neuron has many dendrites that divide forming a system of branches like a tree. The axon is a prolongation of the soma that extends in the opposite direction to the dendrites and has the function of driving a nerve impulse from the soma to another neuron, of the human body. Axons end in ramifications. When the axon encounters the dendrites of another neuron the so-called, “synapse” takes place. During the synapse, the axon and dendrites do not touch due to a small space called a synaptic cleft. The communicative process between two neurons begins with a chemical-electrical discharge in the membrane of one of the neurons (a presynaptic neuron). After said nerve urge reaches the end of the axon, the neuron secretes a substance, called a neurotransmitter, into the synaptic cleft. This neurotransmitter travels a relatively short distance to the dendrites of the other neuron (a postsynaptic neuron). Depending on the type of neurotransmitter that is released, postsynaptic neurons are stimulated or inhibited.
Do you know where you are right now? Your capability to perceive, to see, hear and smell, depends on your nervous system; also, your ability to recognize where you are and remember if you have been there before. Your ability to ask yourself where you are depends on your nervous system! If what you perceive indicates danger, ('Oh no, there is a thief in the house!'), the way you react to that information also depends on your nervous system.
In addition to allowing you to consciously process the threat, your nervous system activates involuntary responses, such as an increase in heart rate and blood flow to the muscles with the intention to help you confront the danger. All these processes depend on the interconnected cells that make up the nervous system. Neurons are the basic operative units of the nervous system and generate electrical signals called action potentials that allow them to transmit information quickly over long distances. Neurons, like other cells, have a cell body. The nucleus of the neuron is in the soma. Neurons need to produce many proteins and the neuronal proteins are synthesized in the soma. Several extensions (appendages or bumps) are projected from the cell body. These include many short-branched extensions, known as dendrites and a separate extension that is usually longer than dendrites, known as axon.
The job of the dendrites is to receive signals from other neurons, to process these signals, and to transfer the information to the soma of the neuron. Dendrites branch and move, just like tree branches do, and they even have leaf-like structures on them called spines. Dendrites carry-on information between neurons. It is then not surprising that malfunctions in dendrites are associated with a variety of disorders of the nervous system. Breakdowns go from abnormal morphology to disturbances in nerve fibre branching, anomalies in dendritic development and malfunctioning loss of dendrite branching and dendrite genesis. All of these are linked to disorders such as schizophrenia, autism, depression, anxiety, Alzheimer’s and Down syndrome, among others.
Axon carries nerve impulses from the cell body. A neuron has one axon that connects it with other neurons or with muscle or gland cells. Some axons are long, reaching from the spinal cord down to a toe. Most axons of vertebrates are enclosed in a myelin sheath, which increases the speed of impulse transmission; some large axons may transmit impulses at speeds up to 90 meters (300 feet) per second.
Neurotransmitters are chemicals released in the brain to allow an impulse from one nerve cell to pass to another nerve cell. There are billions of nerve cells placed within the brain, that do not directly bit each other; nerve cells communicate messages by secreting neurotransmitters. Neurotransmitters can excite or inhibit neurons (nerve cells). Some common neurotransmitters square measure neurotransmitter, norepinephrine, dopamine, serotonin and, gamma-aminobutyric acid (GABA).
Acetylcholine and monoamine neurotransmitter square measure stimulative neurotransmitters whereas Dopastat, serotonin, and GABA are inhibitory. Each neurochemical will directly or indirectly influence neurons in a very specific portion of the brain, thereby affecting behavior. Dopamine-containing neurons in the brain that are damaged, is implicated in schizophrenia, a mental disease marked by disturbances in thinking and emotional reactions. Depression affects one in fifteen adults every year, it is an abnormal excess or lack of signals that control mood, thoughts, pain, and other sensations. Alzheimer’s disease is a progressive degenerative condition, a form of dementia. The disease seems to be caused by a loss of cells that secrete acetylcholine in the basal forebrain (the region of the brain that is the control center for sensory and associative information processing and motor activities). People with “generalized folie (GAD)” expertise excessive worry that causes issues at work and within the maintenance of daily responsibilities. Evidence suggests that GAD involves many neurochemical systems within the brain, including norepinephrine and serotonin.
People stricken by attention-deficit/hyperactivity disorder (ADHD) expertise difficulties within the areas of attention, overactivity, impulse control, and distractibility. Research shows that Dopastat and monoamine neurotransmitter imbalances square measure powerfully involved in inflicting hormone. Valuable analysis proof suggests a relationship of neurochemical imbalance with disorders like borderline temperament disorders, a personality disorder, an avoidant mental disturbance, phobic disorder, a theatrical temperament disorder, and somatization disorder. Neurons are like signals through a cable wire. Nerves are the cable wire and neurotransmitters are signals themselves telling everything else what needs to happen so that they all work together. For us, humans to be able to react to our environment, neurons carry stimuli.
References
- Author Bolonia, C., (2017). What are the parts of a neuron? https://www.lareserva.com
- Author Byrne, J. H. (2016). Introduction to neurons and neuronal networks. https://es.khanacademy.org
- Author Alan, W. (2016) What is a Neuron. https://qbi.uq.edu.au
- Author Kandel, E.R. (2003). Principles of neural science. Cambridge: McGraw Hill.
- Kulkarni, V.A., Firestein, B.L. (2012). The dendritic tree and brain disorders. Molecular and Cellular Neuroscience. https://biologydictionary.net
- https://www.britannica.com/science/axon
- Authors Tasman, et al. 1st ed. Philadelphia: W. B. Saunders Company, 1997.
- http://www.minddisorders.com
