Nervous System Of Human Being

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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, 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. The peripheral nervous system consists of sensory neurons, ganglia (clusters of neurons) and nerves that connect to one another and to the central nervous system.

Central nervous system

The central nervous system consists of the brain and spinal cord. It is referred to as "central" because it combines information from the entire body and coordinates activity across the whole organism.

The brain is protected by the skull (the cranial cavity) and the spinal cord travels from the back of the brain, down the center of the spine, stopping in the lumbar region of the lower back.

The brain and spinal cord are both housed within a protective triple-layered membrane called the meninges.

The central nervous system has been thoroughly studied by anatomists and physiologists, but it still holds many secrets; it controls our thoughts, movements, emotions, and desires. It also controls our breathing, heart rate, the release of some HORMONES, body temperature, and much more.

The brain is the most complex organ in the human body; the cerebral cortex (the outermost part of the brain and the largest part by volume) contains an estimated 15–33 billion neurons, each of which is connected to thousands of other neurons.

total, around 100 billion neurons and 1,000 billion glial (support) cells make up the human brain. Our brain uses around 20 percent of our body's total energy. The brain is the central control module of the body and coordinates activity. From physical motion to the secretion of hormones, the creation of memories, and the sensation of emotion.

To carry out these functions, some sections of the brain have dedicated roles. However, many higher functions — reasoning, problem-solving, creativity — involve different areas working together in networks.

The brain is roughly split into four lobes:

Temporal lobe (green): important for processing sensory input and assigning it emotional meaning. It is also involved in laying down long-term memories. Some aspects of language perception are also housed here.

Occipital lobe (purple): visual processing region of the brain, housing the visual cortex.

Parietal lobe (yellow): the parietal lobe integrates sensory information including touch, spatial awareness, and navigation.

Frontal lobe (pink): positioned at the front of the brain, the frontal lobe contains the majority of dopamine-sensitive neurons and is involved in attention, reward, short-term memory, motivation, and planning.

Spinal cord

The spinal cord, running almost the full length of the back, carries information between the brain and body, but also carries out other tasks. From the brainstem, where the spinal cord meets the brain, 31 spinal nerves enter the cord. Along its length, it connects with the nerves of the peripheral nervous system (PNS) that run in from the skin, muscles, and joints.

Motor commands from the brain travel from the spine to the muscles and sensory information travels from the sensory Tissues — such as the skin — toward the spinal cord and finally up to the brain. The spinal cord contains circuits that control certain reflexive responses, such as the involuntary movement your arm might make if your finger was to touch a flame.

The circuits within the spine can also generate more complex movements such as walking. Even without input from the brain, the spinal nerves can coordinate all of the muscles necessary to walk. For instance, if the brain of a cat is separated from its spine so that its brain has no contact with its body, it will start spontaneously walking when placed on a treadmill. The brain is only required to stop and start the process, or make changes if, for instance, an object appears in your path.

Peripheral nervous system

The peripheral nervous system (PNS) consists of all neurons that exist outside the brain and spinal cord. This includes long nerve fibers containing bundles of axons as well as ganglia made of neural cell bodies. The peripheral nervous system connects the central nervous system (CNS) made of the brain and spinal cord to various parts of the body and receives input from the external Environment as well.

Functionally, the PNS is divided into sensory (afferent) and motor (efferent) nerves, depending on whether they bring information to the CNS from sensory receptors or carry instructions towards muscles, organs or other effectors. Motor nerves can be further classified as somatic or autonomic nerves, depending on whether the motor activity is under voluntary conscious control.

Anatomically, the PNS can be divided into spinal and cranial nerves, depending on whether they emerge from the spinal cord or the brain and brainstem. Both cranial and spinal nerves can have sensory, motor or mixed functions. The enteric nervous system, surrounding the gastrointestinal tract is another important part of the peripheral nervous system. While it receives signals from the autonomic nervous system, it can function independently as well and contains nearly five times as many neurons as the spinal cord.

The primary function of the peripheral nervous system is to connect the brain and spinal cord to the rest of the body and the external environment. This is accomplished through nerves that carry information from sensory receptors in the eyes, ears, skin, nose and tongue, as well as stretch receptors and nociceptors in muscles, glands and other internal organs. When the CNS integrates these varied signals, and formulates a response, motor nerves of the PNS innervate effector organs and mediate the contraction or relaxation of skeletal, smooth or cardiac muscle.

Thus, the PNS regulates internal homeostasis through the autonomic nervous system, modulating Respiration, heart rate, blood pressure, digestion Reproduction and immune responses. It can increase or decrease the strength of muscle contractility across the body, whether it is sphincters in the digestive and excretory systems, cardiac muscles in the heart or skeletal muscles for movement. It is necessary for all voluntary action, balance and maintenance of posture and for the release of secretions from most exocrine glands. The PNS innervates the muscles surrounding sense organs, so it is involved in chewing, swallowing, biting and speaking. At the same time, it mediates the response of the body to noxious stimuli, quickly removing the body from the injurious stimulus, whether it is extremes in temperature, pH, or pressure, as well as stretching and compressing forces.

The nervous system is a complex and amazing system that is essential for life. It is responsible for everything we do, from the simplest movements to the most complex thoughts. Without the nervous system, we would not be able to function.

The nervous system is made up of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

The CNS is made up of the brain and spinal cord. The brain is the control center of the body. It receives information from the senses and sends signals to the muscles to control movement. The spinal cord is a long, thin bundle of nerves that connects the brain to the rest of the body. It carries messages back and forth between the brain and the body.

The PNS is made up of nerves that connect the CNS to the rest of the body. There are two main types of nerves in the PNS: sensory nerves and motor nerves. Sensory nerves carry messages from the body to the brain. Motor nerves carry messages from the brain to the muscles.

The nervous system is responsible for controlling all of the body’s functions. It controls movement, sensation, thought, and emotion. It also regulates the body’s internal environment.

The nervous system is made up of billions of cells called neurons. Neurons are specialized cells that are able to send and receive electrical signals. These signals allow the nervous system to communicate with itself and with other parts of the body.

Neurons are connected to each other by synapses. Synapses are tiny gaps between neurons. When an electrical signal reaches the end of a neuron, it causes the release of chemicals called neurotransmitters. These neurotransmitters cross the synapse and bind to receptors on the next neuron. This binding causes a change in the electrical charge of the next neuron, which may either excite or inhibit it.

The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

The nervous system is responsible for controlling all of the body’s functions. It controls movement, sensation, thought, and emotion. It also regulates the body’s internal environment.

Here are some of the most common disorders of the nervous system:

Alzheimer’s disease: A progressive brain disorder that slowly destroys memory and thinking skills.
Parkinson’s disease: A disorder that affects the nervous system, causing tremors, stiffness, and difficulty with balance and coordination.
Multiple sclerosis (MS): A disease that damages the myelin sheath that protects nerve fibers, causing a variety of symptoms, including numbness, tingling, weakness, and vision problems.
Epilepsy: A neurological disorder that causes seizures, which are sudden episodes of uncontrolled electrical activity in the brain.
Stroke: A sudden loss of brain function caused by a blockage in an artery that supplies blood to the brain.
Head injury: A traumatic injury to the head that can cause a variety of symptoms, including loss of consciousness, headache, and memory problems.
Brain tumor: A Growth of abnormal cells in the brain.
Spinal cord injury: An injury to the spinal cord that can cause paralysis, numbness, and tingling.

These are just a few of the many disorders that can affect the nervous system. If you are experiencing any symptoms that concern you, it is important to see a doctor to get a diagnosis and treatment.

What is the nervous system?

The nervous system is the part of an animal’s body that coordinates the voluntary and involuntary actions of the animal and transmits signals between different parts of its body. In most types of animals it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor or efferent nerves, while those nerves that transmit information from the body to the CNS are called sensory or afferent. Spinal nerves serve both functions and are called mixed nerves. The PNS is divided into three separate subsystems, the somatic, autonomic, and enteric nervous systems. Somatic nerves mediate voluntary movement. The autonomic nervous system is further subdivided into the sympathetic and the parasympathetic nervous systems. The sympathetic system uses noradrenalin as its postganglionic neurotransmitter, and is activated to a large degree during the “fight-or-flight response”. The parasympathetic system uses acetylcholine as its postganglionic neurotransmitter, and is activated when organisms are in a relaxed state. The enteric nervous system functions to control the gastrointestinal system.

What are the functions of the nervous system?

The nervous system is responsible for controlling and coordinating the body’s actions, processing sensory information, and generating emotional and cognitive responses. It is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord, and is responsible for higher-level functions such as thought, memory, and emotion. The PNS consists of nerves that connect the CNS to the rest of the body, and is responsible for transmitting sensory information to the CNS and motor commands from the CNS to the muscles.

What are the different types of neurons?

Neurons are the basic units of the nervous system. They are specialized cells that transmit information in the form of electrical and chemical signals. There are three main types of neurons: sensory neurons, motor neurons, and interneurons. Sensory neurons detect stimuli from the environment and transmit this information to the CNS. Motor neurons transmit signals from the CNS to the muscles, causing them to contract. Interneurons connect sensory neurons to motor neurons and to each other, allowing for complex processing of information.

How does the nervous system work?

The nervous system works by sending electrical signals through neurons. These signals are generated by the movement of ions across the cell membrane of a neuron. When a neuron is stimulated, it opens channels in its membrane that allow sodium ions to flow into the cell. This influx of sodium ions causes the inside of the cell to become more positive, which triggers the opening of other channels that allow potassium ions to flow out of the cell. This outflow of potassium ions causes the inside of the cell to become more negative, which stops the flow of sodium ions into the cell. The neuron then returns to its resting state, ready to be stimulated again.

What are some disorders of the nervous system?

There are many disorders that can affect the nervous system. Some of the most common include:

Alzheimer’s disease: A progressive neurodegenerative disorder that affects memory, thinking, and behavior.
Parkinson’s disease: A movement disorder that causes tremor, stiffness, and difficulty with balance and coordination.
Multiple sclerosis: An autoimmune disease that damages the myelin sheath that protects nerve fibers.
Epilepsy: A neurological disorder characterized by seizures.
Stroke: A sudden loss of blood flow to the brain that can cause permanent damage.
Brain tumor: A mass of abnormal cells that grows in the brain.

How can I protect my nervous system?

There are a number of things you can do to protect your nervous system, including:

Eating a healthy diet: A diet that is rich in fruits, vegetables, and whole grains can help to protect your brain and nervous system.
Getting regular exercise: Exercise helps to improve blood flow to the brain and can help to reduce the risk of stroke.
Managing Stress: Stress can damage the nervous system, so it is important to find ways to manage stress in your life.
Getting enough sleep: Sleep is essential for the health of the brain and nervous system.
Avoiding alcohol and drugs: Alcohol and drugs can damage the brain and nervous system.
Getting regular check-ups: It is important to see your doctor for regular check-ups to screen for any potential problems with your nervous system.

The nervous system is made up of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is made up of the brain and spinal cord, while the PNS is made up of all the nerves that connect the CNS to the rest of the body.
The nervous system is responsible for controlling all the body’s functions, including movement, sensation, thought, and emotion.
The nervous system is made up of billions of nerve cells, called neurons. Neurons communicate with each other using electrical and chemical signals.
The nervous system is divided into two main types of tissue: gray matter and white matter. Gray matter is made up of the cell bodies of neurons, while white matter is made up of the axons of neurons.
The nervous system is a complex and amazing system that is responsible for all the body’s functions.

Here are some MCQs about the nervous system:

Which of the following is not a part of the nervous system?
(A) Brain
(B) Spinal cord
(C) Heart
(D) Muscles
The nervous system is responsible for which of the following?
(A) Movement
(B) Sensation
(C) Thought
(D) All of the above
The nervous system is made up of which of the following types of tissue?
(A) Gray matter
(B) White matter
(C) Both gray and white matter
(D) Neither gray nor white matter
The nervous system is divided into which of the following two main types of tissue?
(A) Gray matter and white matter
(B) Central nervous system and peripheral nervous system
(C) Both gray matter and white matter and central nervous system and peripheral nervous system
(D) Neither gray matter and white matter nor central nervous system and peripheral nervous system
The nervous system is a complex and amazing system that is responsible for which of the following?
(A) All the body’s functions
(B) Movement
(C) Sensation
(D) Thought

Answers:
1. (C)
2. (D)
3. (C)
4. (B)
5. (A)