INTRODUCTION
Heredity endowment or environmental influence or the interaction of human behavior . the cognitive factors including intelligence have been supposed to be potent factors in an underlying behavior , psychological factors like interests , attitudes , emotions and sentiments , mood and temperament , psycho –state and mental and mental health have also been recognized as major influenceble attributes , apart from all these factors , it has been commonly agreed that behavior in all its forms and shapes definitely has a biological or physiological base
The mechanism of the human body not only directs the functioning of the sense organs and the process of growth and maturation but also indicates and influences the delicate and complex process such as thinking , learning and emotional responses , There by , it becomes imperative to pay attention to ‘the mechanism of the human body for the necessary study of human behavior . There are two important and distinct mechanisms , namely , the nervous system and ductless glands that have been adjudged to carry strong influence over human behaviour . let us try to get an idea of these body mechanisms
Human behavior involves the whole organisms or body interaction . The body –mind interaction has two aspects , physical or bodily and mental . these two aspects , influence each other
1] The sense organs called acceptors
2] the muscles and endocrine glands called effectors
3] The nervous system known as the connecting or integrating mechanism
THE SENSE ORGANS
Eyes ears sense of taste – these sense organs receive stimuli from the physical world and our bodily conditions . They consist of the receptors , specialized sensitive cells associated with the endings of sensory nerve fifbres and various accessory apparatus tissues ‘ which although not sensitive themselves , contribute to the effectiveness with which the sense organs function
Each sense organs has a distinct function to perform . The eyes sees but can not smell . The ear hears but does not taste.it is impossible to have sensation of cold or heat , softness or roughness of surface . independent in their functioning . They work together in various combinations . We enjoy a good meal with the help of sight , sight smell taste and temperature sensations . The kinesthic states and visual senses combine to give the body balance and co-ordination
The organs of sight , hearing , smell , pressure , temperature and pain are sensitive to stimuli arising from out side the body . some of the receptors are found in the body cavity and in internal organs . The are stimulated by conditions with in the organism and its activity . They give rise to taste, hunger , thirst , nausea , suffocation and other similar forms of sensitivity . some of the receptors are located between the internal and external surfaces , in the muscles , tendons joints , semicircular canals and vestibules of the ears . They give rise to our kinesthetic sensations and static experiences
Some people believe that our senses develop a greater inherent acuity or sensitivity ,if one sense is lost or is weak . this is a misconception . Actually , there is no increase in acuity or sensitivity . What happens is that with loss of one sense the person directs and trains her attention so that she can make much better use of the remaining sense of organs . Blind people are able to read Braille with their finger prints , not because there is any increase in the acuity or sensitivity of touch , but because they concentrate better on the task and motivation is stronger
THE MUSCLES
Our behavior and activity involves movements of different parts of our body . movements are made when we bathe , dress eat , , walk , run , speak and handle an object . The process of digestion and circulation also imply movements which are essential to life . our muscles are responsible for all these bodily movements , whether they are internal or external
The skeletal muscles or striped muscles enable us to make movements or tendencies to movements by contracting and relaxing . These movements may be evident –over or couret ; walking ,dancing , talking , gesturing , eating , inhibiting a movement , speed , strength and precision of movements involved in these activities depend on the co-ordination and control of muscles . This control of muscles is lost when the nerve centres of fibers are injured or diseased
As a result of prolonged stimulation or exercise as in play or work . these muscles become fatigued , they temporarily lose the power of contracting or responding to stimuli . some waste products are accumulated in the muscles . Rest and sleep help in preventing and curing muscular fatigue
The smooth muscles are responsible for vital processes . They respond to appropriate stimuli in an involuntary , reflexive manner . They are slower to contract and slower to return to a normal state after excitation as compared to the skeletal muscles
MUSCLE TONUS
The human body is composed of different types of cells like bone cells , muscles cells , body cells etc., each type consisting of millions of tiny cells , forms a single unit which has a specialized function . the duty of carrying electrical messages from one part of the body to the other has been assigned to nerve cells .our nervous system is made up of these nerve cells . A nerve cell with all its branches called a neuron . This neuron is the ultimate structure and functional unit of the nervous system . The number of these neurons in a human nervous system has been estimated at 100to 200billion . they are basically –alike in structure but appear in different lengths , sizes and shapes designed for specialized function . With in each neuron , there are millions of RNA molecules , each carrying genetic instructions from the DNA
A neuron has a nucleus A neuron has a nucleus , a cell body , and a cell body called dendrites . their role is to receive messages through electrical impulses from the sense organs or adjacent neurons and carry them to the cell body . The messages from the cell body further travel the length of a nerve fiber known as axon . A group of axon , bundled together like parallel wire ; in an electrical cable referred to as nerve . The axon (but certainly not all of them ) is surrounded by a fatty covering called a sheath . its function is to speed up the transmission of the messages . The messages , thus transmitted are further carried to a muscle or a gland or a neighboring neuron through the terminal branches of the nerve fiber
These neurons or nerve tissues are spread all over the body . there are three types of neurons . The sensory neurons called messages from inside and out side the body and carry them to the spinal card and brain . These neurons collect messages from inside and out side body and carry them to the spinal cord and brain . These neurons help in the processes sensation and perception , The motor neurons carry messages from the brain and spinal cord to the muscles and the glands .
They are responsible for physical movements and activation of glands . The inter neurons or association neurons carry messages from one neuron to another . Their specific role is to carry signals in the form of memories and thoughts and to add reflex or automatic activities
The neural impulse ; Neurons as we have seen are the receivers and transmitters of messages . This message is always in the form electro-chemical impulses . let us see how this work is carried on by neurons
A neuron in its resting position is supposed to maintain a sort of electrical equilibrium i.e., state of polarization . it is because inside the cell membrane of the neuron , there is ‘positively charged ions’ . This state of polarization may be disturbed on effect of the effect of the tugger – like action of a stimulus applied to the membrane . it causes a sudden change in the electrical potentiality of the neuron . it gets depolarized and a neuron or neural impulse is thus initiated
The neuron impulse is not initiated in response to every electrical message (or impulse) it receives . if the incoming message is not strong enough , it will not cause a change , in its electrical potentially and nothing will happen . The incoming message must be above a certain threshold of intensity if it is to cause a neural impulse
In this way , a neuron will either be releasing the neural impulse . This principle is known as the all-or-none law
THE DIVISION OF THE HUMAN NERVOUS SYSTEM
The human nervous system can be divided into two parts ; the central nervous system and the peripherial nervous system
The central nervous system ; The central nervous system is that part of the nervous system which lies with in the body case formed by the skull and spine . The brain and the spinal cord constitute this system
The brain ; it is the control room of the huge complicated telephone system of the body . it is composed of three main divisions, the fore brain , the mild brain and the hind brain
The fore brain ; the fore brain is at the very top of the brain . its important structures are the thalamus , the hypothalamus and the cerebrum . The thalamus consists of two eggs –shaped structures situated in the central core of the brain just over the brainstem . All sensory impulses pass through it to the higher centers . Therefore it is usually known as the relay station . in addition the thalamus seems to exercise some control over the, automatic nervous system and also plays a role in the control of sleep and alertness
The hypothalamus ; it lies below the thalamus . it exerts a ‘key influence ‘ on all kinds of emotional as well as motivational behavior . centres in the hypothalamus excercise control over the important body processes like eating , drinking , sleeping , temperature control and sex . it also exerts control over the activities of the pituitary gland which is located just below it .
The cerebrum ; it lies at the very top of the brain . it is the most complex and largest part of the brain . it extends from the eye brows to the middle of the skull it is divided into two hemisphere ; the left brain which controls behavior in the right and left body sides respectively . A great mass of white matter called the copus callosm connects these these two hemisphere to each other and to the other parts of the nervous system . The cerebrum is covered by a thick layer of tightly packed neurons –called the cerebral cortex . Different areas of the cerebral cortex like sensory projection areas , motor projection areas , mother projection and association areas . motor projection areas and association areas , etc., have been found to be responsible for different functions . in this way , the cerebral cortex , also known as the new brain has the ability to perform the functions of storing sensory information , controlling body movements , co-ordinating all information that comes to the grain and regulating highly cognitive (at the base) . it is particularly concerned those related to hearing and sight to higher brain centers , one of its important structures is known as recticular activating system (RAS) with the help of structure an individual is able to decide which impulses should register consciously and which should be repressed or rejected . consequently it helps him to concentrate on studying even with the radio set on and sleep soundly with the noisy environment
The hinder brain; the hinder brain is situated behind and beneath the fore brain . it rests with in the brain stem . it is composed of three structures , the medulla , the pons and the cerebellum
The medulla; it lies nearest to the spinal cord .it controls breathing and many important reflexes such as those that help us maintain our up right postures like digestion , respiration and circulation which are necessary for the preservation of life
The pons; The pons connects the cerebrum at the top of the brain to the top most section of the hinder brain , the cerebellum
It assists the breathing , transmitting impulses from the cerebellum to the higher brain regions and co-ordinating the activities of both sides of the brain
The cerebellum ; is composed of two circular hemispheres . it helps in performing many bodily functions . it is responsible for the body balance and the coordination of body movements . behaviors , like dancing , typing and playing the piano depend on this structure
FUNCTIOS OF THE BRAIN
As we know , there are a number of mental functions that are performed by our brain whether a specific function that are performed or not ; and how far our mental functions are dependent on several different areas of the brain ; this problem concerning localization of psycho functions in the brain has been a matter of considerable research and experimentation, on the basis of their experiments .Franz and lashely have provided two distinct. Laws on cerebral localization, namely , the law of mass action and the law of equilibrium potentiality
Where the law of mass action means that the learned habits disintegrate in the ration in which the cortex has equal potentiality asserts that every point of cortex is the outer layer of cells of the brain , the grey matter , because, it is the most accessible pert of the brain
1] MOTOR AREA
Motar area of the cerebral cortex lit in the form of narrow strips just in front of the central fissure (a large fold that extends from the top of the head of the ears ).These areas belonging to each hemisphere control the movements of these parts of the get paralyzed when due to one or the other reasons , , the associated motor area suffers extirpation or destruction , Frontal lobes ; The functions of frontal lobes are not well understood . Damage to these areas has resulted in behavioral changes which are so diverse that it is very difficult to find what they have in common . These changes have been described in rather broad terms as involving emotional dulling , distractibility and difficulty in executing sequence of behavior ;
2] bodily sensor area ; the parietal lobes of the brain are connected with the body sensations such as temperature , pain and the feel of the objects . The functioning of the centers located in this area is similar to that of the motor areas , i.e., the centers located in the upper region control the sensations of the lower parts of the body and the centers located in the lower region , control the sensations of the lower parts of the body and the centers located in the lower region contro the sensations of the upper parts of the body
3] visual area ; The visual centers responsible for vision are located in the occipital lobes at the very back of each hemisphere . these centers help the individual in the matter of discriminating and identifying shape , size , distance and color of the environmental objects .destruction of this area in an individual may cause complete blindness in him
4] Auditory centers are located at the side of each hemi sphere in in the temporal lobes . They are responsible for providing various various auditory experiences in terms identification of various sounds stimuli present in the environment . their loss by destruction or damage of this area may cause speech hindrance
5] speech area ; This area responsible for the controlling the conduct of speech lies a bit below the motor area in the frontal lobe . the destruction or damage of this area may cause hindrance
6] Temporal lobes ; in some patients who are being operated or , as a treatment for epilepsy , electrical stimulation in the temporal lobes results in the arousal of memories , usually the same one for given patient . These patients report seeing and hearing scenes from earlier life
7] Association areas is located in the frontal lobe of the brain , just under the forehead . Rather than directly influencing sensory or motor area and are chiefly concerned with higher cognitive functions like thinking and problem solving . A man’s ability to order his behavior and direct it towards a goal depends especially on these areas
SPINAL CORD
It is that part of the central nervous system which lies with in the back bone . it is a rope like structure made up of bundles of long , rounded nerve fibers . The inside of the spinal cord has a grayish color ; while outside the coverings of mylin sheath give it a whiiish appearance , spinal cord function is two fold , in the first place , it works as a channel of communication from and to the brain . Secondly , it works as an organ for effective reflex action
The action , like closing of the eye lid when some thing hot or cold touches it are known as reflex actions . The are controlled by our spinal cord . normally messages are conveyed to the brain by the spinal cord and it is brain that takes the decision . but there are times , when an immediate action is needed . Then the spinal cord and it is brain that takes the decision . but there are times , when an immediate action is needed . Then the spinal cord gets the emergency signal and instead of receiving orders from the brain, it self direct the muscles for necessary movement .normally messages are conveyed to the brain by the spinal cord and it is brain that takes the decision . But there are times , when an immediate action is needed . then the spinal gets the emergency signal and instead of receiving orders from the brain , itself directs the motor nerves to run the muscles for necessary movement
THE PERIPHERAL NERVOUS SYSTEM
The nervous tissues lying outside the bony case of the central nervous system . it consists of a net work of nerves , which helps in passing the sense impressions to the central nervous system as well as in conveying the orders of the central nervous system is sub divided into two parts the somatic system and the autonomic system The somatic system, is both sensory and motor . in this system both sensory and motor nerves leading from the central nervous system for serving the blood vessels , heart glands and the other internal organs of the body and regulating processes such as respiration , digestion , gland functioning and emotion . The auto nervous system consists of two divisions the sympathic system .the homeopathic medicines are hephar sulph. Arsenicum album and others too.
