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Sensory Nervous System Function

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Last Updated: 02 July 2021

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General | Latest Info

The nervous system is a complex collection of nerves and specialized cells known 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 system regulates 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

1. Introduction

As you might predict, human nervous system is very complex. It has multiple divisions, beginning with its two main parts, Central Nervous System and Peripheral Nervous System, as shown in Figure: CNS includes brain and spinal cord, and PNS consists mainly of nerves, which are bundles of axons from neurons. Nerves of PNS connect CNS to the rest of the body. You can learn much more about CNS by reading the concept of Central Nervous System. Pns is divided into two major parts, called autonomic and somatic Nervous systems. The Somatic Nervous System controls activities that are under voluntary control, such as turning the steering wheel. The Autonomic Nervous System controls activities that are not under voluntary control, such as digesting meal. Autonomic Nervous System has three divisions: sympathetic division, which controls fight - or - flight response during emergencies; parasympathetic division, which controls routine housekeeping functions of the body at other times; and enteric division, which provides local control of digestive system. You can learn more about PNS and its subdivisions by reading the concept Peripheral Nervous System.

* 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

4. The olfactory system

Very complex apparatuses were used to investigate the threshold of classical olfactory sensation. It is 1 - 210 14 mol / l in humans and 210 16 mol / l in eels. From the fact that only 10 molecules excite receptor cells and 40 trigger smell perception, it may be calculated that the olfactory system of eel will be stimulated by even a thimbleful of rosewater poured into 16 times the amount of water in Lake Constance and well distribute. This good olfactory sense of fish surely also explains why salmon usually find their home in river. It probably smell Its specific odorants, and this should give us at least some idea of the impact our water pollution has on the olfactory system of fish. Measurements have shown that olfactory threshold changes significantly in relation to nutritional status. Thus, threshold is 1 - 210 14 mol / l in fasting state and rises to 3. 5 - 5. 510 14 mol / l after meal. The biochemical basis for this threshold variation is sugar content in blood. Sugar is a nutritive substance of CNS. It makes sense for olfactory thresholds to differ in fasting state: hungry humans and animals require good olfactory sense for self - preservation, since they must hunt for prey or use olfactory organs for orientation.


Introduction

Olfaction is a chemical sensation of gaseous odorants colloquially referred to as the ability to smell. Olfactory nerves in coordination with other neuroanatomical structures in nasal passages, neurotransmitters, and cerebral cortex are responsible for carrying out this intricate chemosensory process. In humans, olfaction is closely coupled to other complex functions such as gustation and involuntary memory formation. From an evolutionary standpoint, intact sense of smell is critical for evaluating the safety of ingestible substances, assessing impending danger, and recognizing social relationships. The ability to perceive and detect orders tends to decline with normal aging. In a clinical setting, changes in olfaction may represent initial presentation of underlying pathology and warrant thorough medical evaluation.

* 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

5. Animal model systems

Which animal models are used to study sensory nervous systems? The question relates to finding the best animal model to study particular sensory system. Most biological and biomedical research focuses on a small number of animal models, Core Four, mice, zebrafish, fly, and worms because of their genetic tractability. Many other animal species are being used to determine the structure and function of specific sensory system.Sss This is in part mandated by the fact that not all animal species are equipped with the same senses. And even if they possess specific sensory system, it might be rudimentary in its anatomy or simply do not perform functions relevant to species survival. As champion of Neuroethology, Hoy points out that there is a need for nongenetic discovery science, like Neuroethology, that will mine biodiversity of neural systems and behavior mechanisms so that Core Four model species will not become Final Four. As stated by August Krogh many years ago and quoted by others, for large number of problems, there will be some animal of choice or a few such animals on which it can be most conveniently study. Along the same lines, Bernard stated even earlier that in scientific investigation, smallest processes are of utmost importance. Happy choice of animal, instrument built in a certain way, use of one reagent instead of another, are often enough to solve most general questions. In that sense, diversity of species found its way back into neurobiological research and our understanding of sensory nervous system.


Evolution of the Nervous System

Many scientists and thinkers believe that the human nervous system is the most complex machine known to man. Its complexity points to one undeniable factthat it has evolved slowly over time from simpler forms. The evolution of the nervous system is intriguing not because we can marvel at this complicated biological structure, but it is fascinating because it inherits lineage of long history of many less complex nervous systems, and it documents record of adaptive behaviors observed in life forms other than humans. Thus, evolutionary study of the nervous system is important, and it is the first step in understanding its design, its workings, and its functional interface with the environment. The brains of some animals, like apes, monkeys, and rodents, are structurally similar to humans, while others are not. Do anatomical similarity of these brains suggest that behaviors that emerge in these species are also similar? Indeed, many animals display behaviors that are similar to humans,. Eg, apes use nonverbal communication signals with their hands and arms that resemble nonverbal forms of communication in humans. If we study very simple behaviors, like physiological responses made by individual neurons, then brain - base behaviors of invertebrates look very similar to humans, suggesting that from time immemorial such basic behaviors have been conserved in brains of many simple animal forms and in fact are the foundation of more complex behaviors in animals that evolve later. Even at micro - anatomical level, we note that individual neurons differ in complexity across animal species. Human neurons exhibit more intricate complexity than other animals; for example, neuronal processes in humans have many more branch points, branches, and spines. Complexity in the structure of the nervous system, both at macro - and micro - levels, gives rise to complex behaviors. We can observe similar movements of limbs, as in nonverbal communication, in apes and humans, but the variety and intricacy of nonverbal behaviors using hands in humans surpasses apes. Deaf individuals who use American Sign Language express themselves in English nonverbally; they use this language with such fine gradation that many accents of ASL exist. Complexity of behavior with increasing complexity of the nervous system, especially the cerebral cortex, can be observed in the genus Homo. If we compare the sophistication of material culture in Homo habilis and Homo sapiens, evidence shows that Homo habilis used crude stone tools compared with modern tools used by Homo sapiens to erect cities, develop write languages, embark on space travel, and study her own self. All of this is due to the increasing complexity of the nervous system. What has led to the complexity of the brain and nervous system through evolution, to its behavioral and cognitive refinement? Darwin proposes two forces of natural and sexual selection as work engines behind this change. He prophesy, psychology will be based on a new foundation, that of necessary acquirement of each mental power and capacity by gradation. That is, psychology will be based on evolution.

* 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: 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 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: 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 problem 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

Study of the nervous system

The mammalian nervous system is a complex biological organ, which enables many animals, including humans, to function in a coordinated fashion. The original design of this system is preserved across many animals through evolution; thus, adaptive physiological and behavioral functions are similar across many animal species. Comparative study of physiological functioning in nervous systems of different animals lends insights into their behavior and their mental processing and makes it easier for us to understand human brain and behavior. In addition, studying the development of the nervous system in growing humans provides a wealth of information about changes in its form and behaviors that result from this change. The nervous system is divided into central and peripheral nervous systems, and the two heavily interact with one another. Peripheral nervous system Control volitional and nonvolitional behaviors using cranial and spinal nerves. The central nervous system is divided into forebrain, midbrain, and hindbrain, and each division performs a variety of tasks; for example, cerebral cortex in the forebrain houses sensory, motor, and associative areas that gather sensory information, process information for perception and memory, and produce responses based on incoming and inherent information. To study the nervous system, number of methods have evolved over time; These methods include examining brain lesions, microscopy, electrophysiology, electroencephalography, and many scanning technologies.

* 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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