The Human Nervous System

The Human Nervous System

The nervous system is the most complex part of the body, as they govern our thoughts, feelings, and bodily functions. It is an important factor in science because it can lead to new discoveries for cures or diseases. The studies of the nervous system helped lower death rates from heart disease, stroke, accidents, etc. The nervous system is a network of neurons (nerve cells that sends information to the brain to be analyzed.

Neurons live both in and outside the central nervous system. Understanding how the neurons work is vital to understanding the nervous system.

The neuron has two important structures called the dendrite and axon, also called nerve fibers. The dendrites are like tentacles that sprout from the cell and the axon is one long extension of the cell. The dendrites receive signals from other neurons, while the axon sends impulses to other neurons. Axons can extend to more than a meter long. Average sized neurons have hundreds of dendrites; therefore it can receive thousands of signals simultaneously from other neurons. The neuron sends impulses by connection the axon to the dendrites of another nerve cell. The synapse is a gap between the axon and the adjacent neuron, which is where data is transmitted from one neuron to another. The neuron is negatively charged and it bathes in fluids that contain positively charged potassium and sodium ions. The membrane of the neuron holds negatively charged protein molecules. The neuron has pores called ion channels to allow sodium ions to pass into the membrane, but prevent the protein molecules from escaping (potassium ions can freely pass through the membrane since the ion channels mostly restrict sodium ions). When a neuron is stimulated (not at rest), the pores open and the sodium ions rush in because of its attraction to the negatively charged protein molecules, which makes the cell positively charged. As a result, potential energy is released and the neurons send electrical impulses through the axon until the impulse reaches the synapse of any neurons near it.

Once the signal is sent, the ion balances out and becomes at rest. The electrical impulse that runs down the axon releases a chemical called acetylcholine, only one of many chemicals that transmits signals across the synapse. These substances are called neurotransmitters because they transmit data from one ...

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...ransports them to all tissues of the body. Adrenaline excites the heart to increases muscle strength, like the reaction that comes from anxiety. Noradrenaline constricts blood vessels and helps transmit nerve signals. These chemicals are vital to many autonomic activities. Although the autonomic nervous system acts automatically, it is possible to have control of some autonomic functions. Biofeedback is teaching a person to control body functions like reducing heart rate. The benefits are that it can be used to relieve headache by moving blood away from the head to lessen pressure or by lowering high blood pressure. The fact that the body’s automatic functions can be affected by the mind greatly contributes to the understanding of the autonomic nervous system. In conclusion, the nervous system is an important part of science because understanding it can help save lives. Millions were saved from heart attacks, strokes, etc. from treating the nervous system. Understanding about the nervous system is also necessary for psychologists, physicians, and neurologists. Future experiments of the nervous system can benefit the human race by producing cures for presently incurable diseases.