Sending Signals: The Nervous System
The nervous system is the major system of communication within the body. Our thoughts, emotions, and actions are all left up to the signalling done by this system. In tandem with the endocrine system, the nervous system helps regulate and control internal conditions to maintain homeostasis. Most all of the glands discussed in the endocrine system are signaled by nerves to secrete their hormones. However, the nervous system also responds to external stimuli like light and temperature. Every response our body has to any stimulus, whether internal or external, is controlled by the nervous system.
What Conditions And Disorders Affect The Nervous System
Thousands of disorders and conditions can affect your nerves. An injured nerve has trouble sending a message. Sometimes its so damaged that it cant send or receive a message at all. Nerve injury can cause numbness, a pins-and-needles feeling or pain. It may be difficult or impossible for you to move the area thats injured.
Nerve damage can happen in several ways. Some of the most common causes of nerve damage include:
What Happens Following A Spinal Cord Injury
A common set of biological events take place following spinal cord injury:
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How Does A Synapse Work To Communicate Between Cells
The electrical wave causes the neuron to release small chemical neurotransmitters at the synapse , which then travel across to the neuron on the other side of the synapse . This happens very quickly because the space is very, very narrow . When the chemical neurotransmitter reaches the receiving cell, it binds to a molecule called a receptor on the membrane of the receiving cell, kind of like a key going into a lock. This causes the ion channels in the receiving cell to open. Ions then flow into the receiving cell and this creates a new electrical message .
This is also how our neurons communicate with our muscles, telling us when to move. The synapse between a nerve cell and a muscle cell is called the neuromuscular junction . The neurotransmitter released in the neuromuscular junction is called acetylcholine. Just like in neurons, the binding of acetylcholine causes channels to open in the muscle cell, allowing ions to flood into the muscle . This electrical message causes the muscle to contract or shorten. Think about catching a ball: your brain tells a neuron to send an electrical signal to the neuromuscular junction synapse, and this causes neurotransmitter to be released in your finger muscles, so that they contract to catch the ball.
The Autonomic Nervous System
As mentioned above, the autonomic nervous system is divided into the parasympathetic and sympathetic systems. A key role of the PSNS is stimulating saliva production in the mouth and stimulating the stomach and intestines to complete digestion. The PSNS maintains a calm state of arousal, with its function often simplified to rest and digest. Conversely, the SNS creates alertness in the body. When you are scared, you may notice an increased heart rate, faster breathing, and an energized feeling. This is due to the SNS readying your body to face a potential threat. When the threat is gone, the PSNS will return the body to its normal, calmer state. The diagram below details the effects of the PSNS and SNS on the body and also distinguishes the CNS and PNS from one another:
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The Cell Structure Of The Brain
The brain is made up of two types of cells: neurons and glial cells, also known as neuroglia or glia. The neuron is responsible for sending and receiving nerve impulses or signals. Glial cells are non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin and facilitate signal transmission in the nervous system. In the human brain, glial cells outnumber neurons by about 50 to one. Glial cells are the most common cells found in primary brain tumors.
When a person is diagnosed with a brain tumor, a biopsy may be done, in which tissue is removed from the tumor for identification purposes by a pathologist. Pathologists identify the type of cells that are present in this brain tissue, and brain tumors are named based on this association. The type of brain tumor and cells involved impact patient prognosis and treatment.
Problems Of The Nervous System
Some common problems of the nervous system include:
- Epilepsy storms of abnormal electrical activity in the brain causing seizures
- Meningitis inflammation of the membrane covering the brain
- Multiple sclerosis the myelin sheaths protecting the electrical cables of the central nervous system are attacked
- Parkinsons disease death of neurones in a part of the brain called the midbrain. Symptoms include shaking and problems with movement
- Sciatica pressure on a nerve caused by a slipped disc in the spine or arthritis of the spine and, sometimes, other factors
- Shingles infection of sensory nerves caused by the varicella-zoster virus
- Stroke a lack of blood to part of the brain.
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What Are The Parts Of The Brain
The brain has three main sections: the forebrain, the midbrain, and the hindbrain.
The forebrain is the largest and most complex part of the brain. It consists of the cerebrum the area with all the folds and grooves typically seen in pictures of the brain as well as other structures under it.
The cerebrum contains the information that essentially makes you who you are: your intelligence, memory, personality, emotion, speech, and ability to feel and move. Specific areas of the cerebrum are in charge of processing these different types of information. These are called lobes, and there are four of them: the frontal, parietal, temporal, and occipital lobes.
The cerebrum has right and left halves, called hemispheres. They’re connected in the middle by a band of nerve fibers that lets them communicate. These halves may look like mirror images of each other, but many scientists believe they have different functions:
- The left side is considered the logical, analytical, objective side.
- The right side is thought to be more intuitive, creative, and subjective.
So when you’re balancing your checkbook, you’re using the left side. When you’re listening to music, you’re using the right side. It’s believed that some people are more “right-brained” or “left-brained” while others are more “whole-brained,” meaning they use both halves of their brain to the same degree.
In the inner part of the forebrain sits the thalamus, hypothalamus, and :
What Is The Function Of Central Nervous System
The central nervous system is the processing unit of the nervous system. It includes the brain and the spinal cord. It receives nerve impulses from the peripheral nervous system and sends information to the peripheral nervous system in the form of nerve impulses. The brain processes the sensory information and sends the information to the spinal cord. The anatomy of the nervous system is shown in figure 1.
Figure 1: Nervous System
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How Do Synapses Allow Me To See And Hear
Our senses detect the world around us and transform the many external forms of energy into electrical messages in our neurons. In our eyes, for example, there are light-detecting neurons that respond to the things we see . Some of these special neurons detect colored light and some detect just black and white, like an old-fashioned photograph. Light causes channels to open in light-detecting neurons, which sends an electrical message to the synapses of neurons inside your brain . This information is then processed by the brain to interpret the light images.
- Figure 3 – Many synapses communicate within the brain.
- This image is an artist rendition of neurons in your nervous system. The different colors represent the many different types of neurons, such as those that let you see and hear, or learn and remember. The many projections from each neuron represent the many different synapses that neurons make with each other. Many neurons have thousands of synapses, which allow them to receive and integrate lots of different information, and then relay this information on to other neurons. The nervous system has a property called plasticity, which means that new synapses can form as we learn and strengthen as we make memories. Meanwhile, synapses that we do not use shrink or decrease in number. These changes in the brain can alter how neurons communicate.
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How Do Synapses Allow Me To Learn And Remember
One of the most important things about our brains is that the number and size of synapses change when we use them. This property of the brain to change in response to what we experience is called plasticity. Plasticity allows us to learn new information and then to remember what we have learned . If we use our synapses a lot, many more can form. If we do not use them as much, synapses can shrink or decrease in number . The strength of communication between synapses can also change depending on how much we use them. If we use them a lot, this can increase the amount of neurotransmitter released, or the number of neurotransmitter receptors on the receiving cell . Synapses are like muscles they are strengthened by use. If we use our synapses a lot, it can create new, strong synapses that remain in place for many years, even decades . This can help us to form long-term memories. As you know, you can remember things for years think of your mothers face, or your best friend in the first grade.
What Happens When Synapses Do Not Work Properly
Since your synapses are so important for moving, sensing, learning, and remembering, it is easy to see how problems with synapses can cause diseases and disabilities . When synapses do not work properly, the brain cannot communicate within itself and with the muscles. Movement disorders often result from problems at the neuromuscular junction . For example, one disease is caused when the neurotransmitter is not cleared out of the synapse. Acetylcholine is released at the neuromuscular junction synapse to cause muscles to contract. If it is not properly removed afterwards, the acetylcholine will continue to bind muscle receptors. This causes improper muscle contraction and movement, and later results in loss of the receptors, and eventually the loss of the muscles .
Similarly, problems with synapses can cause losses of sensory perception. Deafness can occur due to problems in synapses of our ear hair cells, causing the overactivation of the nerves in the ear . If our hearing neurons are activated over and over again, it takes a stronger electrical message to continue to activate them. As a result, ear hair cells in people with hearing problems need to feel a louder sound in order to pass on the message to the neurons that travel to the brain . In cases of blindness, light receptor synapse problems can cause light-sensitive cells to disappear completely . Thus, light cannot be turned into electrical signals, and the information is not carried into the brain.
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Neurons Lose Their Power
After whisker trimming, neurons in the somatosensory cortex no longer responded more to visual and touch together than either sensory type alone. Click for more detail.
Scientists studied how important early touch and visual information are for developing the ability to combine this information. They did this by trimming the whiskers of rats during the first five days of life. They wanted to know whether trimming the whiskers of a rat during the first five days of life affected its ability to combine senses later in life.
Once the rats were three weeks old and the whiskers regrew, scientists looked at brain activity in response to touch, vision, or a combination of both senses. They were mainly interested in the activity of neurons located within the visual and somatosensory areas of the brain.
Scientists compared the brain activity of rats that had their whiskers trimmed to those that did not. Overall they found that neurons of the visual and somatosensory areas shared less information with each other in adult rats that had their whiskers trimmed. This meant that having touch information a few days after birth was very important for the brain to be able to combine touch and visual information later in life. However, they still did not know why.
How Does The Brain Send Messages Throughout The Body
. Also question is, how fast does your brain send messages to your body?
o How fast does information travel to and from our brain and through our nerves? Information travels at different speeds within different types of neurons . Signals can travel as slow as about 1 mph or as fast as about 268 mph.
Beside above, how is the brain connected to the body? The brain stem connects the brain with the spinal cord. It controls hunger and thirst and some of the most basic body functions, such as body temperature, blood pressure, and breathing. The brain is protected by the bones of the skull and by a covering of three thin membranes called meninges.
Similarly, how does the brain send messages to the body for kids?
The brain connects to nerves that travel throughout the body. Nerves from our senses send signals to the brain to let the brain know what is going on in the outside world. The brain also sends signals using nerves to muscles in order to make our body move.
How fast does brain process information?
However, a team of neuroscientists from MIT has found that the human brain can process entire images that the eye sees for as little as 13 milliseconds the first evidence of such rapid processing speed. That speed is far faster than the 100 milliseconds suggested by previous studies.
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How Does The Brain Receive The Information From The Receptor
A stimulus is a change in the environment of an organism. Animals respond to both internal and external stimuli through their central nervous system . The response to the stimulus helps to maintain the homeostasis or a constant internal environment within them. The CNS is composed of the brain and the spinal cord. Various types of receptors in the body respond to stimuli and generate nerve impulses that are transmitted to the brain and spinal cord through sensory neurons. Brain and the spinal cord process the nerve impulses and the corresponding information is transmitted to the effector organs through motor neurons.
Why Cant The Central Nervous System Repair Itself After Injury
Many organs and tissues in the body can recover after injury without intervention. Unfortunately, some cells of the central nervous system are so specialized that they cannot divide and create new cells. As a result, recovery from a brain or spinal cord injury is much more difficult.
The complexity of the central nervous system makes the formation of the right connections between brain and spinal cord cells very difficult. It is a huge challenge for scientists to recreate the central nervous system that existed before the injury.
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How Does The Brain Send Messages To The Body
The brain is the bodys control centre: it sends messages to your body through a network of nerves called the nervous system, which controls your muscles, so that you can walk, run and move around. The nervous system extends through your body from your spinal cord, which runs from your brain down your backbone, like the branches of a tree.
Show/hide Words To Know
Cerebral Cortex: the outer layers of the brain responsible for important brain functions, like thinking and feeling… more
Fluorescence Microscopy: the use of microscopes and specific colors of light to see fluorescent, or glowing, parts of a cell… more
Retrograde staining: a method to trace the connection between two cells by following the path from where it ends to where it begins.
Somatosensory Cortex: part of the brain that is mainly involved with touch including pressure, pain, and warmth.
Stimulus: a signal that can activate or excite a response from an organism. Foods, sounds, and other triggers that cause specific behaviors or sensory experiences are stimuli.
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