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The Nervous System Functions

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Last Updated: 02 July 2021

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The nervous system is a complex collection of nerves and specialized cells know as neurons that transmit signals between different parts of the body. It is essentially the body's electrical wiring. Structurally, nervous system has two components: central nervous system and the peripheral nervous system. According to the National Institutes of Health, central nervous system is made up of the brain, spinal cord and nerves. The peripheral nervous system consists of sensory neurons, ganglia and nerves that connect to one another and to the central nervous system. Functionally, nervous system has two main subdivisions: somatic, or voluntary, component; and autonomic, or involuntary, component. The Autonomic nervous systems regulate certain body process, such as blood pressure and rate of breathing, that work without conscious effort, according to Merck Manuals. The somatic system consists of nerves that connect the brain and spinal cord with muscles and sensory receptors in the skin.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Nervous System Anatomy

Nervous Systems can be divided into two major regions: Central and Peripheral Nervous systems. The Central Nervous System is the brain and spinal cord, and the Peripheral Nervous System is everything else. The brain is contained within the Cranial cavity of the skull, and the spinal cord is contained within the vertebral cavity of the vertebral column. It is a bit of an oversimplification to say that CNS is what is inside these two cavities and the Peripheral Nervous System is outside of them, but that is one way to start to think about it. In fact, there are some elements of the Peripheral Nervous System that are within cranial or vertebral cavities. Peripheral Nervous System is so named because it is on peripherymeaning, beyond the brain and spinal cord. Depending on different aspects of the Nervous System, dividing line between Central and Peripheral is not necessarily universal. Nervous tissue, present in both CNS and PNS, contains two basic types of cells: neurons and glial cells. The Glial cell is one of a variety of cells that provide the framework of tissue that supports neurons and their activities. Neuron is more functionally important of two, in terms of the communicative function of the Nervous System. In order to describe the functional divisions of the Nervous System, it is important to understand the structure of neuron. Neurons are cells and therefore have soma, or cell body, but they also have extensions of cell; each extension is generally referred to as a process. There is one important process that every neuron has called axon, which is fiber that connects the neuron with its target. Another type of process that branches off from soma is dendrite. Dendrites are responsible for receiving most of the input from other neurons. Looking at nervous tissue, there are regions that predominantly contain cell bodies and regions that are largely composed of just axons. These two regions within Nervous System structures are often referred to as gray matter or white matter. Figure 2 demonstrates the appearance of these regions in the brain and spinal cord. Colors ascribed to these regions are what would be seen in fresh, or unstained, nervous tissue. Gray matter is not necessarily gray. It can be pinkish because of blood content, or even slightly tan, depending on how long tissue has been preserve. But white matter is white because axons are insulated by a lipid - rich substance called myelin. Lipids can appear as white material, much like fat on raw piece of chicken or beef. Actually, gray matter may have that color ascribed to it because next to white matter, it is just darkerhence, gray. The distinction between gray matter and white matter is most often applied to Central Nervous tissue, which has large regions that can be seen with the unaided eye. When looking at peripheral structures, often a microscope is used and tissue is stained with artificial colors.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Nervous System Physiology

The brain and spinal cord together form the central nervous system, or CNS. Cns acts as the control center of the body by providing its processing, memory, and regulation systems. CNS takes in all of conscious and subconscious sensory information from the bodyas sensory receptors to stay aware of the bodyas internal and external conditions. Using this sensory information, it makes decisions about both conscious and subconscious actions to take to maintain the bodyas homeostasis and ensure its survival. CNS is also responsible for higher functions of the nervous system such as language, creativity, expression, emotions, and personality. The brain is the seat of consciousness and determines who we are as individuals. The peripheral nervous system includes all of the parts of the nervous system outside of the brain and spinal cord. These parts include all of the cranial and spinal nerves, ganglia, and sensory receptors. Somatic nervous system is a division of PNS that includes all of voluntary efferent neurons. Sns is only consciously control part of PNS and is responsible for stimulating skeletal muscles in the body. Autonomic nervous system is a division of PNS that includes all involuntary efferent neurons. Ans controls subconscious effectors such as visceral muscle tissue, cardiac muscle tissue, and glandular tissue. There are 2 divisions of the autonomic nervous system in the body: sympathetic and parasympathetic divisions. Sympathetic. Sympathetic division forms body afight or flighta response to stress, danger, excitement, exercise, emotions, and embarrassment. Sympathetic division increases respiration and heart rate, releases adrenaline and other stress hormones, and decreases digestion to cope with these situations. Parasympathetic. Parasympathetic division forms the bodyas arest and digesta response when the body is relax, resting, or feeding. Parasympathetic works to undo work of sympathetic division after stressful situation. Among other functions, parasympathetic division works to decrease respiration and heart rate, increase digestion, and permit elimination of wastes. Enteric nervous system is a division of ANS that is responsible for regulating digestion and function of digestive organs. Ens receives signals from the central nervous system through both sympathetic and parasympathetic divisions of the autonomic nervous system to help regulate its functions. However, ENS mostly works independently of CNS and continues to function without any outside input. For this reason, ENS is often called abrain of guta or bodyas asecond brain. Ens is an immense systemaalmost as many neurons exist in ENS as in the spinal cord.


Functions of the Nervous System

The nervous system has 3 main functions: sensory, integration, and motor. Sensory. The sensory function of the nervous system involves collecting information from sensory receptors that monitor the bodyas internal and external conditions. These signals are then passed on to the central nervous system for further processing by afferent neurons. Integration. The process of integration is the processing of many sensory signals that are passed into CNS at any given time. These signals are evaluate, compare, used for decision making, discarded or committed to memory as deemed appropriate. Integration takes place in gray matter of the brain and spinal cord and is performed by interneurons. Many interneurons work together to form complex networks that provide this processing power. Motor. Once networks of interneurons in CNS evaluate sensory information and decide on action, they stimulate efferent neurons. Efferent neurons carry signals from gray matter of CNS through nerves of the peripheral nervous system to effector cells. Effector may be smooth, cardiac, or skeletal muscle tissue or glandular tissue. Effector then releases hormones or moves part of the body to respond to stimulus. Unfortunately, of course, our nervous system does always function as it should. Sometimes this is a result of diseases like Alzheimeras and Parkinsonas disease. Do you know that DNA testing can help you discover your genetic risk of acquiring certain health conditions that affect organs of our nervous system? Late - onset Alzheimeras, Parkinsonas disease, macular degeneration - visit our guide to DNA health testing to find out more.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Diagnosing nervous system conditions

The Nervous system is a complex, highly specialized network. It organize, explains, and directs interactions between you and the world around you. The nervous system controls: sight, hearing, taste, smell, and feeling. Voluntary and involuntary functions, such as movement, balance, and coordination. Nervous systems also regulate actions of most other body systems, such as blood flow and blood pressure. Ability to think and reason. The nervous system allows you to be conscious and have thoughts, memories, and language. The nervous system is divided into brain and Spinal cord and nerve cells that control voluntary and involuntary movements. Symptoms of nervous system problem depend on which area of the nervous system is involved and what is causing the problem. Nervous system problems may occur slowly and cause gradual loss of function. Or they may occur suddenly and cause life - threatening problems. Symptoms may be mild or severe. Some serious conditions, diseases, and injuries that can cause nervous system problems include: blood supply problems. Injuries, especially injuries to the head and spinal cord. Problems that are present at birth. Mental health problems, such as anxiety disorders, depression, or psychosis. Exposure to toxins, such as carbon monoxide, arsenic, or lead. Problems that cause gradual loss of function. Examples include: Parkinson's disease. Multiple sclerosis. Amyotrophic lateral sclerosis. Alzheimer's disease. Huntington's disease. Peripheral neuropathies. Infections. These may occur in the: Brain. The Membrane surrounds the brain and spinal cord. Overuse of or withdrawal from prescription and nonprescription medicines, illegal drugs, or alcohol. Brain tumor. Organ system failure. Examples include: Respiratory failure. Heart failure. Liver failure. Kidney failure. Other Conditions. Some examples include: Thyroid dysfunction. High blood sugar or low blood sugar. Electrolyte problems. Nutritional deficiencies, such as vitamin B1 or vitamin B12 deficiency. Guillain - Barre syndrome. Sudden nervous system problems can cause many different symptoms, depending on the area of nervous system involve. Strokes and transient ischemic attacks are common examples of acute problems. You may experience sudden onset of one or more symptoms, such as: numbness, tingling, weakness, or inability to move part or all of one side of your body. Dimness, blurring, double vision, or loss of vision in one or both eyes. Loss of Speech, trouble talking, or trouble understanding speech. Sudden, severe headache. Dizziness, unsteadiness, or inability to stand or walk, especially if other symptoms are present. Confusion or change in level of consciousness or behavior. Severe nausea or vomiting. Seizures can also cause sudden changes in consciousness, feeling,s emotion,s or thought.S Abnormal body movements, such as muscle twitching, may or may not be present. How often seizures occur and how severe they are depends on the cause of seizures and the area of the brain involve. For more information, see topic Seizures. Diabetes can cause problems with balance, either as a result of peripheral neuropathy or stroke. Vertigo and Dizziness are problems of balance and coordination.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Diseases of the nervous system

Nervous system that functions correctly is fantastically complex, well - oil machines fire appropriately, muscles move when needed, memories are formed and store, and emotions are well regulate. Unfortunately, each year millions of people in the United States deal with some sort of Nervous System disorder. While scientists have discovered potential causes of many of these diseases, and viable treatments for some, ongoing research seeks to find ways to better prevent and treat all of these disorders. Neurodegenerative Disorders are illnesses characterized by loss of Nervous System functioning that are usually caused by neuronal death. These diseases generally worsen over time as more and more neurons die. Symptoms of particular neurodegenerative disease are related to where in the nervous system, death of neurons occurs. Spinocerebellar ataxia, for example, leads to neuronal death in the cerebellum. The Death of these neurons causes problems with balance and walking. Neurodegenerative Disorders include Huntingtons disease, Amyotrophic lateral sclerosis, Alzheimers disease and other types of dementia disorders, and Parkinsons disease. Here, Alzheimers and Parkinsons disease will be discussed in more depth. Alzheimer's disease is the most common cause of dementia in the elderly. In 2012, estimate 5. 4 million Americans suffer from Alzheimer's disease, and payments for their care are estimated at $200 billion. Roughly one in every eight people aged 65 or older has the disease. Due to the aging of the baby - boomer generation, there is projected to be as many as 13 million Alzheimer's patients in the United States in the year 2050. Symptoms of Alzheimer's disease include disruptive memory loss, confusion about time or place, difficulty planning or executing tasks, poor judgment, and personality changes. Problems smelling certain scents can also be indicative of Alzheimer's disease and may serve as an early warning sign. Many of these symptoms are also common in people who are aging normally, so it is the severity and longevity of symptoms that determine whether a person is suffering from Alzheimers. Alzheimer's disease was named after Alois Alzheimer, German Psychiatrist who published a report in 1911 about a woman who showed severe dementia symptoms. Along with his colleagues, he examined women's brain following her death and reported the presence of abnormal clumps, which are now called amyloid plaques, along with tangled brain fibers called neurofibrillary tangles. Amyloid plaques, neurofibrillary tangles, and overall shrinking of brain volume are commonly seen in the brains of Alzheimer's patients. Loss of neurons in the hippocampus is especially severe in advanced Alzheimer's patients. Figure 16. 30 compare normal brain to the brain of an Alzheimers patient.S Many research groups are examining causes of these hallmarks of disease. One form of disease is usually caused by mutations in one of three known genes. This rare form of early onset Alzheimers disease affects fewer than five percent of patients with the disease and causes dementia beginning between the ages of 30 and 60. The more prevalent, late - onset form of disease likely also has a genetic component.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Study of the nervous system

It has been known for almost 50 years that dissociated embryonic cells, if artificially mixed together, can sort themselves out in tissue - specific manner, ectodermal cells associating with ectodermal cells, mesodermal with mesodermal, and so on. Recently, developmental neurobiologists have taken advantage of this phenomenon to explore molecular basis for selective associations of neurons during development. A number of cell - surface molecules that seem to mediate such cell - cell interactions have also been identified and genes that encode them have been clone. One such cell - adhesion molecule, referred to as N - CAM because it is predominantly expressed in neural tissue, shows homophilic binding has been referred to in Chapter 5. It is widely distributed on surfaces of all neurons and occurs on certain nonneuronal cells as well. During development, it undergoes characteristic embryonic - To - adult modification with an increase in binding affinity. Second, term NG - CAM, because of its presumed role in neuron - glial interactions, exhibits heterophilic binding. Recent immunocytochemical studies have established that NG - CAM is preferentially expressed on growing axons. Antibodies to N - CAM selectively prevent nerve cell aggregation in vitro and also perturb normal neurite fasciculation. Widespread distribution of both molecules at key stages in development of the brain and spinal cord suggests that they may each play a critical role in several of the morphogenetic events being considered here. However, there is at present no conclusive evidence that they are specifically involved in selective aggregation of neurons to form various nuclear groups and conical layers that characterize CNS or various ganglia of the Peripheral Nervous System. However, rapid progress has been made in the past decade on these and several other related cell - cell and cell - substrate adhesion molecules, and this continues to be an area of promise for future investigation. When cells migrate away from the ventricular zone, they display many differentiated features characteristic of neurons or glia, but their major phase of differentiation usually occurs only after they have reached their final destinations. Formally, one can recognize three aspects to this phase of neuronal differentiation. First, cells acquire distinctive morphology, usually characterized by development of several dendrites and single axon. Second, cells acquire a number of distinctive membrane properties. These properties generally do not all emerge simultaneously, but appear over period of time. The third aspect of neuronal differentiation is associated with adoption of a particular mode of synaptic transmission. In most neurons, cells synthesize one or more neurotransmitters or neuromodulators and generate all the necessary cellular machinery for their transport to axon terminals and for their exocytotic release. Simultaneously, cells express a variety of receptor molecules that become inserted into appropriate postsynaptic sites on their own surfaces. Recently, researchers have focused on cloning of genes for peptide transmitters, enzymes involved in synthesis of more conventional neurotransmitters, and receptor molecules involved in synaptic transmission. This work holds great promise that regulation of these molecular aspects of neuronal differentiation will soon be well understood.


Neurons

Workhorses of nervous system that do all of these things that allow Timmy to see butterflys and recognize them are called neurons. Neurons are specialized cells of the nervous system that transmit signals throughout the body. So, now that Timmy's neurons have gathered information from the environment, relayed this information to his brain, process information into visuals and categorize what he see, Timmy now has a decision to make. What does he do with this information? Does he ignore it and continue scanning the backyard, or does he make use of this information and act on it?

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

What Does the Brain Do?

The brain is made up of three main sections: forebrain, midbrain, and hindbrain. The forebrain is the largest and most complex part of the brain. It consists of the cerebrum area with all folds and grooves typically seen in pictures of the brain as well as some other structures under it. Cerebrum contains information that essentially makes us who we are: our intelligence, memory, personality, emotion, speech, and ability to feel and move. Specific areas of cerebrum are in charge of processing these different types of information. These are called lobes, and there are four of them: frontal, parietal, temporal, and occipital lobes. Cerebrum has right and left halves, called hemispheres. They are re connected in the middle by a band of nerve fibers that let them communicate. These halves may look like mirror images of each other, but many scientists believe they have different functions: left side is considered 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 left side. When you re listening to music, you re using right side. It's believed that some people are more right - brain or leave - brain while others are more whole - brain, meaning they use both halves of their brain to the same degree. The outer layer of the cerebrum is called the cortex. Information collected by five senses comes into the brain to cortex. This information is then directed to other parts of the nervous system for further processing. For example, when you touch a hot stove, not only do message go out to move your hand but one also goes to another part of your brain to help you remember not to do that again. In the inner part of the forebrain sits the thalamus, hypothalamus, and pituitary gland: thalamus carries messages from sensory organs like eyes, ears, nose, and fingers to the cortex. The hypothalamus controls pulse, thirst, appetite, sleep patterns, and other processes in our bodies that happen automatically. The Hypothalamus also controls the pituitary gland, which makes hormones that control growth, metabolism, water and mineral balance, sexual maturity, and response to stress. The midbrain, underneath the middle of the forebrain, acts as master coordinator for all messages going in and out of the brain to the spinal cord. The hindbrain sits underneath the back end of the cerebrum. It consists of cerebellum, pons, and medulla. The cerebellum is also called little brain because it looks like a small version of the cerebrum is responsible for balance, movement, and coordination. Pons and medulla, along with midbrain, are often called brainstem. The brainstem takes in, sends out, and coordinates the brain's messages. It also controls many of the body's automatic functions, like breathing, heart rate, blood pressure, swallowing, digestion, and blinking.


Brain and Nervous System

The Central Nervous System, or CNS for short, is made up of the brain and spinal cord. Cns is a portion of the nervous system that is encase in bone. It is referred to as Central because it is the brain and spinal cord that are primarily responsible for processing sensory informationtouching hot stove or seeing rainbow, for exampleand, sending signals to the peripheral Nervous System for action. It communicates largely by sending electrical signals through individual nerve cells that make up fundamental building blocks of the Nervous System, called neurons. There are approximately 100 billion neurons in the human brain and each has many contacts with other neurons, called synapses. If we were able to magnify the view of individual neurons, we would see that they are cells made from distinct parts. Three main components of neuron are dendrites, soma, and axon. Neurons communicate with one another by receiving information through dendrites, which act as antenna. When dendrites channel this information to the soma, or cell body, it builds up as an electro - chemical signal. This electrical part of the signal, called action potential, shoots down axon, long tail that leads away from soma and toward the next neuron. When people talk about nerves in the Nervous System, it typically refers to bundles of axons that form long neural wires along which electrical signals can travel. Cell - to - cell communication is helped by the fact that the axon is covered by a myelin sheath layer of fatty cells that allow signals to travel very rapidly from neuron to neuron. If we were to zoom in still further, we could take a closer look at synapse, space between neurons. Here, we would see that there is space between neurons, called the synaptic gap. To give you a sense of scale, we can compare the synaptic gap to the thickness of the dime, thinnest of all American coins. You could stack approximately 70 000 synaptic gaps in the thickness of a single coin! As action potential, electrical signal reaches the end of the axon, tiny packets of chemicals, called neurotransmitters, are release. This is chemical part of electro - chemical signal. These neurotransmitters are chemical signals that travel from one neuron to another, enabling them to communicate with one another. There are many different types of neurotransmitters and each has a specialized function. For example, serotonin affects sleep, hunger and mood. Dopamine is associated with attention, learning and pleasure. It is amazing to realize that when you thinkwhen you reach out to grab a glass of water, when you realize that your best friend is happy, when you try to remember the names of parts of the neuronwhat you are experiencing is actually electro - chemical impulses shooting between nerves!


What is the central nervous system?

Neurons connect with one another to send and receive messages in the brain and spinal cord. Many neurons working together are responsible for every decision make, every emotion or sensation felt, and every action take. The complexity of the central nervous system is amazing: there are approximately 100 billion neurons in the brain and spinal cord combine. As many as 10 000 different subtypes of neurons have been identify, each specializing in sending and receiving certain types of information. Each neuron is made up of a cell body, which houses nucleus. Axons and dendrites form extensions from the cell body. Astrocytes, kind of glial cell, are primary support cells of the brain and spinal cord. They make and secrete proteins called neurotrophic factors. They also break down and remove proteins or chemicals that might be harmful to neurons. Astrocytes aren't always beneficial: after injury, they divide to make new cells that surround the injury site, forming a glial scar that is a barrier to regenerating axons. Microglia are immune cells for the brain. After injury, they migrate to the site of injury to help clear away dead and dying cells. They can also produce small molecules called cytokines that trigger cells of the immune system to respond to injury site. This clean - up process is likely to play an important role in recovery of function following spinal injury.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

How Does It Work?

The basic workings of the nervous system depend lot on tiny cells called neurons. Brain has billions of them, and they have many specialized jobs. For example, sensory neurons send information from eyes, ears, nose, tongue, and skin to the brain. Motor neurons carry messages away from the brain to the rest of the body. All neurons relay information to each other through a complex electrochemical process, making connections that affect the way you think, learn, move, and behave. Intelligence, learning, and memory. As you grow and learn, messages travel from one neuron to another over and over, creating connections, or pathways, in the brain. It's why driving takes so much concentration when someone first learns it, but later it is second nature: pathway becomes establish. In young children, brain is highly adaptable. In fact, when one part of a young child's brain is injure, another part often learns to take over some of the lost function. But as you age, brain has to work harder to make new neural pathways, making it harder to master new tasks or change set behavior patterns. That's why many scientists believe it's important to keep challenging the brain to learn new things and make new connections. It helps keep the brain active over the course of a lifetime. Memory is another complex function of the brain. Things you 've do, learn, and see are the first process in your cortex. Then, if you sense that this information is important enough to remember permanently, it's passed inward to other regions of the brain for long - term storage and retrieval. As these messages travel through the brain, they too create pathways that serve as the basis of memory. Movement. Different parts of the cerebrum move different body parts. The left side of the brain controls movements of the right side of the body, and the right side of the brain controls movements of the left side of the body. When you press your car's accelerator with your right foot, for example, it's side of your brain that sends a message allowing you to do it. Basic body functions. Part of the peripheral nervous system called autonomic nervous system controls many of body processes you almost never need to think about, like breathing, digestion, sweating, and shivering. The Autonomic nervous system has two parts: sympathetic nervous system and parasympathetic nervous system. The sympathetic nervous system prepares the body for sudden stress, like if you witness a robbery. When something frightening happens, sympathetic nervous system makes the heart beat faster so that it sends blood quickly to different body parts that might need it. It also causes adrenal glands on top of the kidneys to release adrenaline, hormone that helps give extra power to muscles for quick getaway. This process is known as the body's fight or flight response. The parasympathetic nervous system does the opposite: It prepares the body for rest.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Sources

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

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