A Report Of The Nervous System

The report are divided into two parts. first we will be talking about the Organization of the Nervous System, that includes the Peripheral Nervous system, and the Central Nervous system, then we will move on to the Brain and Behavior part, where we will start to talk about the brain and listing down the three major regions of the brains, and how each brain has its own functions different than the other regions, even though they are all located in the brain.

In this report, you will find information about organs or nervous systems found in the human body, beginning with the definitions, describing its structure and functions in the body, illnesses or disorders that affects that part in the body.

Part 1: Organization of Nervous System:


The Nervous System is a world in itself, we’ve learned only the little tidbits of its secrets, but there are many of what we still do not know, and in this section of the report, we will try to identify the anatomic configuration of the nervous system, its division and branches, and the function of each part of it, and the problems resulting in every part.

The communication in the nervous system is essential to behavior. If you’ve wondered how you are aware of the elements in the environment surrounding you, you hear with your ears and see with your eyes, and be aware of many things by touching and smelling and tasting, following this awareness a response coming from you, so you move or talk or touch and hold things. You receive the influential in a very short time, and this can be done by the nervous system, moreover, the nervous system controls the other organs that works voluntary such as holding up things or the involuntary such as heartbeat rate.

Nervous System chart
Nervous system sections:

The nervous system are divided into two main divisions:

Peripheral Nervous System.

Central Nervous System “CNS”. (the brain and spinal cord)

First comes first. We will start with the peripheral nervous system.

The peripheral nervous system: is made up of all those nerves that lie outside the brain and spinal cord. Nerves are bundled of neuron fibers (axons) that are routed together in the peripheral nervous system.

The peripheral nervous system are made off nerves and neurons that sends and receive information to and from the brain.

The peripheral nervous system are subdivided into two parts, the autonomic nervous system and somatic nervous system.

Let us have a look at the Autonomic Nervous System.

Autonomic Nervous System:
The autonomic nervous system (ANS) is made up of nerves that connect to the heart, blood vessels, smooth muscles, and glands.

The autonomic nervous system function is to maintain the internal environment of the human body in a stable state, sometimes called “homeostasis”. Maintaining and balancing the internal environment by controlling visceral organ functions that people don’t normally think about. like heart rate, blood pressure, digestion and perspiration.

The Autonomic nervous system mobilized bodily resources in times of need. Just as its name, this nervous system works automatically, without the control or conscious of the individuals, these which we do not directly control are like closing your eyes, the increase of heartbeat, sweat or produce saliva by stimulating our salivary glands.

For example, right when you first experience fear, the Autonomic nervous system will start and work on to control the involuntary, visceral functions that are difficult to control consciously. How it does it work: when you see something frightening or threatening your life, and happens to throw fear into you, your heartbeat rate will rise, sweating, pupil dilation, goose bumps and increased respiration.

Even thought the Autonomic nervous system works unconsciously, we can sometimes be aware that our heartbeat rate has increased.

One of the first psychologists to study this reaction is Walter Cannon (1932). He referred it to as the fight-or-light response reaction. Cannon monitored this response from cats after confronting them with dogs. From his observation on the cats response, he concluded that what prepares generally any organisms physiologically for attacking (fight) or fleeing from (flight) the enemy is the response to a threat, or when faced to danger.

Illness and diseases affecting the Autonomic Nervous System:

There are diseases and illnesses affecting the autonomic nervous system, causing a disorder in the system, which this disorder effects the controlling of the heartbeat rate and blood pressure of the body that can lead into causing serious problems to the patient, some of these disorders can be life-threatening when they affect the breathing or heart function of the patient.

Some of these diseases are Diabetes, Alcoholism and Parkinson’s disease. Disorders made by the diseases can either affect the whole system, or a part of it.

The Sympathetic and Parasympathetic Divisions:

The Autonomic Nervous System are subdivided into the Sympathetic division and the Parasympathetic division.

The Sympathetic Division:
The sympathetic division is the branch of the autonomic nervous system that mobilizes the body’s resources for emergencies.

As we stated before, the sympathetic nervous system is a sub part of the Autonomic Nervous System. This system is responsible for controlling functions that mobilize the body’s resources under stress, such as the fight or flight response, and the other energy generation forms as well.

Not only the sympathetic nervous system prepares the body when faced with stress or emergencies, but it also serves other vital purposes. Example, if you stand up after being setting down for a long period of time, your blood pressure will raise, else you may fall unconscious. The sympathetic nervous system also works in increasing your heartbeat rate and perspiration during exercises.

Diseases affecting the Sympathetic nervous system:

A disease affecting the sympathetic nervous system known as reflex sympathetic dystrophy syndrome (RSDS). The signs of this dieses are the heightened sensitivity to heat and cold, excessive sweating, and limbs being warm to the touch. The causes of this dieses are not confirmed, but its seems to be associated with some forms of nerve injury.

The Parasympathetic Division:

Like the sympathetic, it is a sub part of the Autonomic Nervous System, and most what the parasympathetic division controls are visceral and involuntary organs, such as breathing and blood pressure and heartbeat rate, But it differ from the sympathetic division in its activities. The parasympathetic division are responsible in controlling the body organs when in an relaxed or normal state. Some of its activities when the conditions are met, and those condition can be met when the person are calmed and relaxed, is reducing the heartbeat rate, slow down the respiratory rate, increases perspiration and salivation and smaller eye pupils.

The Sympathetic and Parasympathetic divisions activities are the opposite of each other, but they work together to maintain stability in the body when a certain external condition are met and calls for the division that are responsible to act in such situation. Much like an automobile accelerators and brakes.

The Central Nervous System:

The Central Nervous System are responsible of controlling the whole body, regulating the functions of the body. The Central Nervous System are the control center of the body.

The central nervous system (CNS) consists of the brain and the spinal cord. The Central Nervous system lies within the skull and the spinal column, protected by enclosing sheaths known as the meninges, additionally, the central nervous system is covered by the cerebrospinal fluid. The cerebrospinal fluid (CSF) nourishes the brain and provides a protective cushion for it. Ventricles are the hollow cavities in the brain that are filled with CSF.

Diseases affecting the central nervous system:

diseases and infections of the central nervous system are many, some of these diseases are Alzheimer’s disease.

The Spinal Cord and The Brain:

So we know now that the Central Nervous System consists of two things, the brain and the spinal cord. Let us have a look at these two organs:

The Spinal Cord:

Basically, the spinal cord is an extension of the brain. The spinal cord are located at the back of the body and are enclosed by the backbone “Vertebral column”, running from the base of the brain to below the waist, and are covered by the meninges.

The spinal cord connects the brain to the whole body through the peripheral nervous system, conducting sensory information to the brain from the peripheral nervous system, And from the brain, the spinal cord works on conducting motor information to the glands, skeletal, cardiac, and smooth muscles. The Spinal cord also serves as a minor reflex center.

The spinal cord consist of bundles of axons, and these axons carry out the commands from the brain to the peripheral nerves, that relays sensation from the periphery of the body to the brain.

Spinal Cord Injury:

Injury to the spinal cord can damage it, causing a partial or full paralysis to the body. Injury can be a result from a car accident or from a serious fall, or any other form of injury that damages the spinal cord, like a gunshot.

The Brain:

The brain is the part that of the central nervous system that fills the upper part of the brain. The brain is enclosed by the skull. The average weighs of the brain are 1.3 kg, three pounds, and contains billions of nerve cells that links and relays information in and outside the body, Such as coordinating the body actions and movements, talking, thinking, remembering, planning, creating and dreaming.

The brain are covered by the meninges, moreover, the brain contains bundles of axons, that works on receiving sensory information from its own nerves, as well as from the spinal cord.

Brain Injury:

Injuries to the brain can be the result of a car accident, or any other form of damage or hit directed to the head. Children’s or infants can possibly get a brain injury if shaken violently.

Part 2: The Brain and Behavior


The Brain, and how it controls our behavior. All of the body movements, thinking, dreaming, talking, remembering, feeling, and any other actions, are controlled by the brain. The Brain is the control room of your body. From the brain, commands are issued and sent to the whole body, and these commands are carried out, in and out by the nerves.

In this part of the report, we will shed some light on the brain, and how every region in the brain has functions different than the other regions, even though they are located in the same organ.

The Three Regions of the Brain:

The brain has three regions, The Hindbrain, the Midbrain and the forebrain. The location of the three regions are the same, but differ in function and size of region. The Forebrain is taking the largest portion of the brain, then comes the Hindbrain, and smallest is the Midbrain.

Structure and Areas of the Brain:
The Hindbrain:
The hindbrain includes the cerebellum and two structures found in the lower part of the brainstem: the medulla and the pons.

The controlling of essential body function and process, such as heartbeat rate and respiration, is the Hindbrain responsibility. An important part of the Hindbrain, the brainstem, controls functions such as swallowing and breathing, and any other critical functions that affect the life of the living being.

The Medulla are attached to the spinal cord, controls unconscious vital functions, such as blood pressure, heartbeat rate, swallowing, breathing and coughing. The Medulla works without relying on the thoughts of the person, It works by itself.

The pons, sometimes called the “Bridge”, because of its form of structure which looks like a bridge connecting between the medulla and the cerebellum. From its structure form, we can know that it works on sending signals to and from the cerebellum and the cerebrum, a part located in the forebrain. The Pons contains clusters of cell bodies that helps in controlling movements and sleep.

The Cerebellum, which means “Little brain” in Latin, Is a large and a folded structure located rear lower portion of the brain. The role of the cerebellum is providing feedback and fine-tuning for motor output. The cerebellum controls movements and smoothing them up, such as when you bring up your hand and smoothly bring your finger to a stop on your nose, and how you walk, and every action or movement that people make without any thinking about them or concentration, are coordinated by the cerebellum.

The Midbrain:
The midbrain is the segment of the brainstem that lies between the hindbrain and the forebrain.

The Midbrain, The smallest region of the brain regions, are responsible for visual and auditory and motor system information station. motor and sensory functions are directly controlled by the midbrain. An Important system of dopamine- releasing neurons, which originates in the midbrain, projects into various high centers of the brain.

Conscious, voluntary movements has dopamine system are involved in their performance. Degeneration or decline in dopamine synthesis is associated with Parkinson’s’ disease.

The reticular formation, which are located at the central core of the brainstem, is the structure that runs through the hindbrain and the midbrain. The reticular formation contribute in the modulate of breathing, reflexes and pain perception.

The Forebrain:
The forebrain is the largest and most complex region of the brain, encompassing a verity of structures, including the thalamus, hypothalamus, limbic system, and cerebrum.

The three structures, the Thalamus, hypothalamus and the limbic system, form the core of the forebrain. The location of the three structures are near the top of the brainstem. The cerebrum sits above the three structures. The cerebral cortex, the outer layer of the brain, is the wrinkled surface of the cerebrum.

So now we know that the Forebrain, which takes the biggest portion of the brain, and the biggest of the three regions, consists of four structures, the Thalamus, Hypothalamus, Limbic system and cerebrum. Let us have a quick look on each structure and its activities and functions.

The Thalamus:
The thalamus is a structure in the forebrain through which all sensory information (except smell) must pass to get to the cerebral cortex.

The Thalamus which is located at the top of the brainstem, is responsible for relaying sensory information to a particular part of the cortex, and regulating motor control. It also works on receiving information and signals from various brain areas, such as auditory, visual sensory, and samotosensory signals.

The Hypothalamus:
The hypothalamus is a structure found near the base of the forebrain that is involved in the regulation of basic biological needs.