Neurons In Nervous Tissue Relay Rapid
All nervous tissue, from the brain to the spinal cord to the furthest nerve branch, includes cells called neurons. Neurons are charged cells: they conduct electrical signals to pass information through the body. A typical neuron consists of a cell body, dendrites, and an axon with an axon terminal. The dendrites receive signals from body tissues or other neurons and pass them into the cell body. If an outgoing signal is produced, it zips down the axon to the axon terminal and passes to the next neuron or target cell. This conductive capability sends information up and down nerve pathways and through the central nervous system at incredible speed. Some 100 billion neurons give the brain its awesome processing power.
Development Of The Nervous System
Before the formation of the nervous system in the embryo, 3e main cell layers become differentiated. The innermost layer, the endoderm, gives rise to the gastrointestinal tract, the lungs, and the liver. The mesoderm gives rise to the muscle, connective tissues, and the vascular system. The third and outer most layer, the ectoderm, formed of columnar epithelium, gives rise to the entire nervous system and skin.
During the third week of development, the ectoderm on the dorsal surface of the embryo between the primitive knot and the buccopharyngeal membrane becomes thickened to form the neural plate.
The plate, which is pear shaped and wider cranially, develops a longitudinal neural groove. The groove now deepens so that it is bounded on either side by neural folds. With further development, the neural folds fuse, converting the neural groove into a neural tube. Fusion starts at about the midpoint along the groove and extends cranially and caudally so that in the earliest stage, the cavity of the tube remains in communication with the amniotic cavity through the anterior and posterior neuropores.
How Do I Keep My Nervous System Healthy
Your nervous system is the command center for your entire body. It needs care to keep working correctly. See your doctor regularly, eat a healthy diet, avoid drugs, and only drink alcohol in moderation. The best way to avoid nerve damage from disease is to manage conditions that can injure your nerves, such as diabetes.
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Right Brain Left Brain
The cerebrum is divided into two halves: the right and left hemispheres They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.
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 Central Nervous System Differ From Other Systems Of The Body
Most systems and organs of the body control just one function, but the central nervous system does many jobs at the same time. It controls all voluntary movement, such as speech and walking, and involuntary movements, such as blinking and breathing. It is also the core of our thoughts, perceptions, and emotions.
What Are The Parts Of The Brain
The brain is made up of 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 some other structures under it.
The cerebrum contains the information that essentially makes us who we are: our 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 :
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What Are The 2 Main Parts Of The Nervous System
AkashThe nervous system has two main parts:
- The central nervous system is made up of the brain and spinal cord.
- The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.
How many nervous systems are there? Structurally, the nervous system has two components: the central nervous system and the peripheral nervous system. According to the National Institutes of Health, the central nervous system is made up of the brain, spinal cord and nerves.
Cerebrum The Cerebrum Is The Largest Part Of The Brain It Is Divided Into 2 Halves Called The Left And Right Cerebral Hemispheres The 2 Hemispheres Are Connected By A Bridge Of Nerve Fibres Called The Corpus Callosum The Right Half Of The Cerebrum Controls The Left Side Of The Body The Left Half Of The Cerebrum Controls The Right Side Of The Body The Cerebral Cortex Is The Outer Folded Part Of The Brain It Is Also Called The Grey Matter The Cerebral Cortex Is Mostly Made Up Of The Cell Bodies And Dendrites Of Nerve Cells Cell Bodies Contain The Nucleus And Other Main Parts Of The Cell Dendrites Are The Short Branching Fibres That Receive Signals From Other Nerve Cells The Inner Part Of The Cerebrum Is Called The White Matter It Is Mostly Made Up Of The Long Fibres Of A Nerve Cell That Send Signals To And From The Brain To The Rest Of The Body The Fatty Coating That Surrounds Axons Gives This Part Of The Brain A Whitish Appearance Each Hemisphere Is Divided Into 4 Sections Called Lobes These Include The Frontal Parietal Temporal And Occipital Lobes
Each lobe has different functions:
The frontal lobe controls movement, speech, behaviour, memory, emotions and intellectual functions, such as thought processes, reasoning, problem solving, decision-making and planning.
The parietal lobe controls sensations, such as touch, pressure, pain and temperature. It also controls the understanding of size, shape and direction .
The temporal lobe controls hearing, memory and emotions. The dominant temporal lobe also controls speech.
The occipital lobe controls vision.
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What Does The Nervous System Do
Your nervous system uses specialized cells called neurons to send signals, or messages, all over your body. These electrical signals travel between your brain, skin, organs, glands and muscles.
The messages help you move your limbs and feel sensations, such as pain. Your eyes, ears, tongue, nose and the nerves all over your body take in information about your environment. Then nerves carry that data to and from your brain.
Different kinds of neurons send different signals. Motor neurons tell your muscles to move. Sensory neurons take information from your senses and send signals to your brain. Other types of neurons control the things your body does automatically, like breathing, shivering, having a regular heartbeat and digesting food.
The Central Nervous System In Your Body
Claudia Chaves, MD, is board-certified in cerebrovascular disease and neurology with a subspecialty certification in vascular neurology.
The central nervous system is comprised of the brain and spinal cord. The CNS receives sensory information from the nervous system and controls the body’s responses. The CNS is differentiated from the peripheral nervous system, which involves all of the nerves outside of the brain and spinal cord that carry messages to the CNS.
The central nervous system plays a primary role in receiving information from various areas of the body and then coordinating this activity to produce the body’s responses.
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Things That Can Go Wrong With The Brain
Because the brain controls just about everything, when something goes wrong, its often serious and can affect many different parts of the body. Inherited diseases, brain disorders associated with mental illness, and head injuries can all affect the way the brain works and upset the daily activities of the rest of the body.
Here are some of the problems that can affect the brain:
Brain tumors. A tumor is an abnormal tissue growth in the brain. A tumor in the brain may grow slowly and produce few symptoms until it becomes large. Or a tumor can grow and spread rapidly, causing severe and quickly worsening symptoms.
Brain tumors can be benign or malignant. They usually grow in one place and may be curable through surgery if theyre located in a place where they can be removed without damaging the normal tissue near the tumor. A malignant tumor is cancerous and more likely to grow rapidly and spread.
Cerebral palsy. This condition is the result of a developmental defect or damage to the brain before or during a childs birth, or during the first few years of life. Cerebral palsy affects the motor areas of the brain. A person with cerebral palsy may have average intelligence or can have severe developmental delays or mental retardation.
Headaches. Of the many different types of headaches, some of the more common are:
Reviewed by: Yamini Durani, MDDate reviewed: October 2012
Inner Structures Of The Brain
Several structures are located deep within the brain and are important for communication between the brain and spinal cord or the rest of the body. These structures include the hypothalamus and thalamus. Figure \ shows where these structures are located in the brain. The cerebrum, hypothalamus, and thalamus exist in two halves, one in each hemisphere.
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How Does It Work
The messages traveling in your nerves are sent through billions of nerve cells called neurons. The spaces between these cells are called synapses. The cells are linked to one another through chemicals called neurotransmitters that move across the synapses to the next neuron. Dopamine and serotonin are types of neurotransmitters.
This process continues until the message gets to the right place. Some messages move faster than 200 miles per hour.
This is also how messages get from your body back to your brain and spinal cord. For example, if you step on something sharp, the nerves in your foot send a message from neuron to neuron to your central nervous system that says, Hey, this hurts. Your brain and spinal cord respond with a message to your foot: Pull away now.
What Does The Brain Do
The brain controls what we think and feel, how we learn and remember, and the way we move and talk. But it also controls things we’re less aware of like the beating of our hearts and the digestion of our food.
Think of the brain as a central computer that controls all the body’s functions. The rest of the nervous system is like a network that relays messages back and forth from the brain to different parts of the body. It does this via the spinal cord, which runs from the brain down through the back. It contains threadlike nerves that branch out to every organ and body part.
When a message comes into the brain from anywhere in the body, the brain tells the body how to react. For example, if you touch a hot stove, the nerves in your skin shoot a message of pain to your brain. The brain then sends a message back telling the muscles in your hand to pull away. Luckily, this neurological relay race happens in an instant.
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Injuries To The Spinal Cord
Physical damage to the spinal cord may result in paralysis, which is a loss of sensation and movement in part of the body. Paralysis generally affects all the areas of the body below the level of the injury because nerve impulses are interrupted and can no longer travel back and forth between the brain and body beyond that point. If an injury to the spinal cord produces nothing more than swelling, the symptoms may be transient. However, if nerve fibers in the spinal cord are badly damaged, the loss of function may be permanent. Experimental studies have shown that spinal nerve fibers attempt to regrow, but tissue destruction usually produces scar tissue that cannot be penetrated by the regrowing nerves, as well as other factors that inhibit nerve fiber regrowth in the central nervous system.
Feature: My Human Body
Each year, many millions of people have a stroke, and stroke is the second leading cause of death in adults. Stroke, also known as cerebrovascular accident, occurs when poor blood flow to the brain results in the death of brain cells. There are two main types of strokes:
- Ischemic strokes occur due to a lack of blood flow because of a blood clot in an artery going to the brain.
- Hemorrhagic strokes occur due to bleeding from a broken blood vessel in the brain.
They are summed up by the acronym FAST, as explained in the chart below.
How Does The Brain Work
The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.
Some messages are kept within the brain, while others are relayed through the spine and across the bodys vast network of nerves to distant extremities. To do this, the central nervous system relies on billions of neurons .
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Functions Of The Central Nervous System
- B.A., Biology, Emory University
- A.S., Nursing, Chattahoochee Technical College
The central nervous system consists of the brain and the spinal cord. It is part of the overall nervous system that also includes a complex network of neurons, known as the peripheral nervous system. The nervous system is responsible for sending, receiving, and interpreting information from all parts of the body. The nervous system monitors and coordinates internal organ function and responds to changes in the external environment.
The central nervous system functions as the processing center for the nervous system. It receives information from and sends information to the peripheral nervous system. The brain processes and interprets sensory information sent from the spinal cord. Both the brain and spinal cord are protected by a three-layered covering of connective tissue called the meninges.
Within the central nervous system is a system of hollow cavities called ventricles. The network of linked cavities in the brain is continuous with the central canal of the spinal cord. The ventricles are filled with cerebrospinal fluid, which is produced by specialized epithelium located within the ventricles called the choroid plexus. Cerebrospinal fluid surrounds, cushions, and protects the brain and spinal cord from trauma. It also assists in the circulation of nutrients to the brain.
Central Nervous System: Brain And Spinal Cord
Our bodies couldnt operate without the nervous system – the complex network that coordinates our actions, reflexes, and sensations. Broadly speaking, the nervous system is organised into two main parts, the central nervous system and the peripheral nervous system .
The CNS is the processing centre of the body and consists of the brain and the spinal cord. Both of these are protected by three layers of membranes known as meninges. For further protection, the brain is encased within the hard bones of the skull, while the spinal cord is protected with the bony vertebrae of our backbones. A third form of protection is cerebrospinal fluid, which provides a buffer that limits impact between the brain and skull or between spinal cord and vertebrae.
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The Brain And Spinal Cord Are The Central Nervous System Nerves And Sensory Organs Make Up The Peripheral Nervous System
Together, the central nervous system and the peripheral nervous systems transmit and process sensory information and coordinate bodily functions. The brain and spinal cord function as the control center. They receive data and feedback from the sensory organs and from nerves throughout the body, process the information, and send commands back out. Nerve pathways of the PNS carry the incoming and outgoing signals. Twelve pairs of cranial nerves connect the brain to eyes, ears, and other sensory organs and to head and neck muscles. Thirty-one pairs of spinal nerves branch out from the spinal cord to tissues of the thorax, abdomen, and limbs. Each nerve is responsible for relaying sensory information, sending motor commands, or both.
Subdivisions Of The Peripheral Nervous System
The sensory division carries sensory signals by way of afferent nerve fibers from receptors in the central nervous system . It can be further subdivided into somatic and visceral divisions. The somatic sensory division carries signals from receptors in the skin, muscles, bones and joints. The visceral sensory division carries signals mainly from the viscera of the thoracic and abdominal cavities.
The motor division carries motor signals by way of efferent nerve fibers from the CNS to effectors . It can be further subdivided into somatic and visceral divisions. The somatic motor division carries signals to the skeletal muscles. The visceral motor division, also known as the autonomic nervous system, carries signals to glands, cardiac muscle, and smooth muscle. It can be further divided into the sympathetic and parasympathetic divisions.
The sympathetic division tends to arouse the body to action. The parasympathetic divisions tend to have a calming effect.
Nerve fibers of the PNS are classified according to their involvement in motor or sensory, somatic or visceral pathways. Mixed nerves contain both motor and sensory fibers. Sensory nerves contain mostly sensory fibers they are less common and include the optic and olfactory nerves. Motor nerves contain motor fibers.
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