This article explains the characteristics and functions of the nervous systems in detail. Without further ado, lets directly explain the functions of the nervous systems
- Functions of the Nervous Systems
- Different parts of the Brain
- Major Characteristic Functions of the Central Nervous System:
- Nervous structure
Functions of the Nervous Systems
The nature and functions of the nervous systems are as below:
Autonomic Nervous System
As the name implies, the autonomic nervous system uses to function independently and in its self-adjusted way. This type of nerves run through the heart, blood vessels, glands, lungs, stomach, intestines, and other visceral parts and the smooth muscles of the body. The autonomic nerves are connected with both sides of the spinal cord. They are not dependent on the sensory regions and sensory experiences of the body. They are also not directly connected nor regulated by the brain but by the spinal cord. Nerve fibers are extended from it to the internal regions stated above and perform an activity in their own way. This type of nerves conducts biochemical functions of the internal parts and gives effect to the emotional experiences of pleasure and pain.
The autonomic nervous system is sub-divided into two parts on the basis of their functions- Sympathetic and Para-Sympathetic.
The sympathetic nervous system may act as excitatory and the Para-sympathetic nervous system may act as an inhibitory agent of the organism. As such, these two systems controls and influence our emotional experiences in accordance with the situation.
Peripheral Nervous System
On the basis of their location, this type of nervous system may be sub-divided into spinal nerves and cranial nerves.
Spinal nerves are located on both sides of the spinal cord with a total of 31 parts. They are white fiber, like nerves extended to different external sensory regions of the body.
Further, they may again be sub-divided into afferent or sensory nerves and efferent or motor nerves carrying sense impressions and motor responses respectively to and from the brain. Sensory nerves are nerves of knowledge and motor nerves are nerves of movement.
Cranial nerves are making the nervous connection of the sense organs and the muscles of the body with the brain. There are a total of 12 pairs of cranial nerves working for it. These nerves cannot be clearly divided into sensory and motor nerves. Some of them may only work as efferent or motor nerves, whereas the others may work both as sensory and motor nerves.
Central Nervous System
The central nervous system is the center of direction and regulation of all forms of our psycho-physical reaction and behavior. Keeping in view of its basic functional differences, it may be divided into two parts – the spinal cord of the vertebra and the brain.
It is bundles of nerves that lie within the backbone. There are altogether 31 small parts of the back-bone joined one another that constitutes a hole in the middle.
The spinal cord is the highway of the sensory and motor impulses that run to and from the brain and different parts of the body. Besides, there are 31 pairs of spinal nerves that run into the spinal cord.
Each nerve has two roots, a dorsal and also a ventral. The dorsal and ventral fibers carry sensory and motor impulses respectively. If the ventral fibers are damaged one suffers from paralysis of the connected part of the body.
Functions of the spinal cord are as follows:
- It connects the brain with different parts of the body.
- It works as a passage covering the sensory and motor impulses.
- Also, it directly controls and regulates the reflex actions like the blinking of eyelids, sneezing, coughing, and salivation.
- It controls habitual and automatic activities like walking, running, and knitting that does not require voluntary attention.
It is the highly developed complex region of our mental function contained within the bony cavity of the skull. It is composed of the grey matter outside and white matter inside.
Besides, the brain consists of some high-powered nerve cells capable of inter-communication of the incoming and outgoing nervous impulses. It is the center of all forms of higher mental activities like thought, intelligence, and emotional reactions. It further consists of different parts like the cerebrum, cerebellum, midbrain, thalamus, medulla oblongata, and pons varolli working in perfect co-ordination. Their structure and functions may be are below, in brief.
Different parts of the Brain
It covers the larger part of the brain and is the seat of all forms of higher mental activities. The cerebrum may be divided into two halves called the right and left hemispheres. They are connected by a thick band of fibers called the corpus callosum. Further, the surface of this part is covered by a layer of grey matter with convolutions or twisting folds called the cerebral cortex.
This part is again subdivided into four lobes or areas as frontal, parietal, occipital, and temporal. Brain works relating to different sensory experiences are localized here. They are the Visual area, auditory area motor area coordinating area, speech center, writing center, and so on. Even though there is the localization of brain function, yet it works in co-ordination and with complete harmony of these lobes as one compact unit.
There are two fissures or narrow opening on the cerebral cortex. They are named as (a) Fissure of Rolando and (b) Fissure of Sylvius, one from right top to left bottom and the other from left bottom to right top.
The functions of the cerebrum brain are highly complicated. They may be sorted out below.
- It controls and regulates all parts of the body and their psycho-physical activities.
- It receives information from all the receptor organs and sends messages to them.
- Specific areas of the cerebrum are concerned with receiving and processing the sense experiences.
- Also, it controls all the voluntary muscular activities and behavior of the individual.
- It acts as the center of all forms of intellectual activities like memory, thinking, reasoning, and problem-solving.
- Feeling and emotions experienced in different situations are also originated from this part of the brain.
- Different sensory areas and the lobes function as a unitary whole.
This part of the brain is located behind and beneath the cerebrum for which it is also known as the hindbrain. Its weight appears to be about 140 grams. It has two equal parts joined by the connector. Its surface is marked by long hollow outs.
Further, the cerebellum is mainly responsible for maintaining the equilibrium of the body and steadiness of its movement. Physical coordination and control and muscular movement depend on this part. Manual dexterity and motor skill required in all forms of games and sports, art, and craft are controlled by it.
Its functions are as follows.
- It is also called the hindbrain.
- Its weight is about 140 grams.
- It maintains body equilibrium.
- Also, it maintains the steadiness of movement.
- Further, it controls and coordinates muscular movement.
- Manual dexterity, motor skill, etc. depend upon it.
- Finer senses of art, painting, drawing, and games and Sports are dependent upon it.
It is the part of the brain that finds itself between the cerebrum and cerebellum. It is in fact the extended lower part of the cerebrum. Also, it contains fiber tracts that connect the cerebrum with the lower parts of the nervous system. The afferent and the efferent nerves originate from this part of the brain. So, it may be described as a relay center of the nervous impulses. It takes charge of locomotion that does not involve a higher mental function of the brain. The nature of the physical motion of an individual is regulated by this part of the brain.
It is located at the center of the brain just below the cerebrum. It looks like two oval-shaped parts joined each other. There are four different parts of it named as dorsal thalamus, epi-thalamus, hypo-thalamus, and sub-thalamus. The dorsal thalamus is the part through which the sensory impulses pass on to the cerebrum and for that, it is also known as the sensory center. The rest of the three parts act as a motor center. At the time of emotion, the motor nerves of these parts are excited. As such, it is believed that the hypothalamus part is the seat of our emotions.
This is the upper part of the spinal cord which contains the nerve cells and fiber tracts connecting the cerebrum. It is a swelling pan and seems to be like a ball that joins the brain with the spinal cord. It may be described as a pathway for incoming and outgoing nervous impulses of the body. This part of the brain is also the center of blood circulation and respiratory function. A person may even die if this part is injured. Medulla oblongata also acts as a sleep center.
It is a thick bundle of fibers that connect the two halves to the cerebellum with the cerebrum and the medulla oblongata. It forms a bridge between the vital parts of the brain. The nerve fibers of the right part of the cerebrum pass through the left part and the left part of the cerebrum passes through the right part of the pons Varolii. As such the right hemisphere of the brain affects the left side and the left hemisphere affects the right side of the body.
Major Characteristic Functions of the Central Nervous System:
From the above description of the human brain following the characteristic functions of the central nervous system are:
- The central nervous system may be divided into two parts as the spinal cord and the brain.
- Reflex actions and motor movements are controlled by the spinal cord.
- The cerebrum is responsible for all forms of higher mental activities.
- There is the localization of functions of the brain, so far as the sensory experiences are concerned.
- Different parts of the brain work in co-ordination as a unique whole.
- The right hemisphere of the cerebrum controls the left side and the left hemisphere controls the right side of the body.
- The Hypo-thalamus part controls the emotional experience of an individual.
- Cerebellum keeps physical balance and equilibrium and controls habitual action.
- Medulla oblongata acts as a coordinating center of the sensory and motor nerves.
- Medulla oblongata also acts as the sleep center.
In order to have a clear picture of the psycho-physical build-up of an individual, it is essential to know the types of the nervous system and the nervous structure of the body. The nervous system of the Human body may be divided into three parts. They are:
- Autonomic nervous system: This nervous system may be sub-divided into two parts based on their functions. They are- sympathetic and Para-sympathetic.
- Peripheral Nervous System: It is sub-divided into two parts again. They are- spinal nerves and cranial nerves.
- Central Nervous System: It is sub-divided into two parts. They are- spinal cord of the vertebra and the brain.
Higher Secondary Education for HS 1st Year
By: Jatin Borua
Note: There are some changes in the Length and Text of the Article.
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