The biology of behavior involves the interaction between the body and mind. The document discusses the key bodily factors involved - receptors (sense organs), effectors (muscles and glands), and the nervous system. It provides details on the structure and functions of neurons, neurotransmitters, and the main parts of the brain and nervous system involved in behavior. The biology of behavior examines how activity in the nervous system relates to both behavior and mental processes.

1. PRESENTED BY
MR.VIVEKANANDA D S
B.SC(N) M.S(C&P)
BIOLOGY OF
BEHAVIOUR

2. The biology of behavior is the study of behavioral functions
of the nervous system, particularly the brain. "Physiological
psychology" is the branch of psychology which seeks to
determine how activity in the nervous system is related to
behavior & the mind.
Human behavior involves the body-mind interaction of the
various bodily factors. The most important are: 1. The sense
organs, called receptors. 2. The muscles & endocrine glands
called effectors 3. The nervous system known as the
connecting or integrating mechanism.

3. Body and its Functions
 Body composed 4 main compartments Head, trunk, hands,
feet.
 It has 5 sense organs-eyes. ears, nose, tongue and skin.
 5 organs of action-feet, hands, mouth, excretory, rectum.
 Functionary systems- Respiratory, blood circulatory,
skeletal, digestive, endocrine and excretory systems
 There is strong physiological and anatomical basis for
explaining our behavior in all situations of our life.

4. MIND AND ITS FUNCTIONS
 WHAT IS MIND?
 WHERE IS IT LOCATED?
o Mind is not reality –hypothetical construct
o It doesn’t lie anywhere in our body-we should not confuse
it with brain or nervous system.
o It is associated with various mental process and activities.
o The functioning of our mind improves or gets developed
with growing age.

5. BODY-MIND RELATIONSHIP
Psychology studies human behavior which involves both body
& the mind.
• They are interrelated & interact upon each other.
• Mental functions & physical states affect each other.
• Body & the mind are two aspects of the living, dynamic &
adjusting personality.
• Mind is regarded as a function of the body; it does not exist
apart from the body.
• It is some total of various mental process such as observing,
knowing, thinking, reasoning, feeling, imagining,
remembering, judging & others.

6. MODULATION PROCESS IN HEALTH & ILLNESS
EFFECTS OF BODILY CONDITIONS ON MENTAL
FUNCTIONING-
 Increased blood pressure causes mental excitement.
 Severe pain reduces the concentration level.
 Chronic illness causes depression.
 Malfunctioning of the endocrine glands may exert a full influence on one’s
personality, resulting in lethargy, nervous tension etc.
 Physical fatigue affects our mood and reduces motivation, interest and
concentration.
 Brain injury affects many psychological functions.
 Well developed brain leads to better development of intellectual
functioning.

7. MODULATION PROCESS IN HEALTH & ILLNESS
EFFECTS OF MENTAL CONDITIONS ON BODILY
FUNCTIONING-
 Unpleasant emotions like fear, anger & worry cause irritability,
insomnia, headache etc. mental processes are intimately connected
to brain or cortical processes.
 Emotional conflicts are responsible for peptic ulcer, ulcerative
colitis etc.
 Deep thinking & concentration can cause physical strain.
 Repressed feelings and aggression are expressed through nervous
system and causes hypertension and cardiac diseases.
 Unconscious motivation and conflicts gives rise to many physical
complaints and neurological (conversion) disorders.

8. HEREDITY
 Heredity is the basis for the development of human
personality.
 Heredity is considered as “the sum total of inborn
individual traits”.
 Biologically, it has been defined as “the sum total of traits
potentially present in the fertilized ovum”.
 According to Douglas & Holland “one’s heredity consists
of all the structures, physical characteristics, functions or
capacities derived from parents, other ancestry or species”.
 The life cycle of an individual begins with the fusion of a
sperm and ovum(conception).

9.  In the fertilized ovum, there are 23(46) pairs of
chromosomes, half of which are given by the father and
the other half by the mother.
 Each chromosome is made up of many genes, which
appear to be the actual determiners of traits.
 One gene(DNA,RNA) may influence many characteristics
or traits or conversely many genes may combine to
determine one characteristic.
 The heredity basis of individual differences lies in the
unlimited variety of possible gene combinations that can
occur. No two siblings get an identical heredity, as they do
not get the same genes from parents.

10.  Fraternal or dizygotic twins are different from each other
because of different pairs of germ cells.
 Identical or monozygotic twins have exactly the same set
of genes and therefore, resemble each other completely.
 Determination of traits is not only due to combination of
genes, but also due to their dominant or recessive nature.
 Some characters are sex linked, i.e one sex shows the
characteristics, while other sex not apparently affected is
the carrier.
 Heredity is the raw material in the hands of the artist, out
of which the potter or tailor prepare the specific objects.

11. ENVIRONMENT
 The child inherits the traits and characteristics of his
parents and forefathers through genes at the time of
conception. Therefore, what he possesses at the time of
conception is all due to heredity.
 After conception, how he develops is the outcome of the
interaction between his hereditary characteristics and
environment. The forces of environment begin to play their
part and influence the growth and development of an
individual right from the time of the fertilization of the
ovum by the sperm. Therefore, what happens after birth is
important but also what goes inside the womb of the
mother after conception has equal significance.

12.  Environment covers the social, moral, economical,
political, physical and intellectual factors, which
influence the development of individual from time to
time.
Definitions-
 The environment is everything that affects the individual
except his genes. -Boring, Langfield and Weld
 Environment covers all the outside factors that have
acted on the individual, since he began life. -Woodworth

13.  Environmental forces can be divided into 2 major heads
1.Internal environment- From conception to till his birth in
the womb of the mother (9months).
• Embryo receives the nutrition, through the blood stream
of its mother.
• Physical & mental health of the mother including her
habits, attitudes & interests etc. all constitute inner
surroundings that affects the growth and development of
individual .

14. 2. External environment-After his birth what the child
gets in terms of environmental influences is purely external
in nature.
It can be further divided into 3 sub-parts
A. Physical environment: Non-living things like water, air,
housing, soil, climate, heat, light, radiation, noise, etc. form
the physical environment. These affect the body and mind
of the growing child. So, it is necessary to provide a decent
home and locality for good physical and mental health of
the child.

15. B.Biological environment: It refers to the living component of
man’s external environment, which consists of plants,
animals, insects, bacteria and viruses. It is necessary that the
child should be allowed to grow in a good, healthy biological
environment. The child should be kept away from the disease
carrying germs, bacteria and viruses.
C.Psychosocial(Socio-cultural) environment: It includes
cultural values, customs, habits, beliefs, attitudes, morals,
religion, education, occupation, social and political
organization, etc. Parents, members of the family, friends,
classmates, neighbors, teachers, mass communication and
recreation, libraries are also included in this environment.

16.  These different environmental forces have a desirable
impact upon the physical, social, emotional, intellectual,
moral and aesthetic development of an individual.
 Their influence is a continuous one, which begins with the
emergence of life and goes on till death.
 Therefore, it is always advisable to consider the sources
like one's heredity and environmental factors for
determining the behavior or development of some specific
personality traits.

17. BRAIN AND BEHAVIOUR
 The entire behavior is effectively managed and controlled
by the coordination and functioning of the nervous system.
 How we will behave in a particular situation depends upon
the judgment of our brain.
 The sense impressions, which are received through the
sense organs, do not bear any significance unless they are
given a meaning by the nervous system.
 Learning also to a great extent is controlled by the
nervous system.
 The proper growth and development of nerve tissues and
nervous system as a whole helps in the task of proper
intellectual development.

18.  Any defect in the spinal cord or the brain seriously affects the
intellectual growth.
 The emotional behavior is also influenced by the nervous
system, especially at the time of anger, fear and other
emotional changes. During emotional outbursts, nerve tissues
cause the change in the secretion of hormones by some glands
and consequently influence the emotional behavior of an
individual.
 The process of growth and development is also directly
and indirectly controlled by the functioning of the nervous
system.
 The personality of an individual is greatly influenced through
the mechanism of the nervous system.

19.  Human behavior involves the body-mind interaction of
the various bodily factors. The most important are:
 The sense organs, called receptors.
 The muscles and endocrine glands, called effectors.
 The nervous system known as the connecting or
integrating mechanism.

20. Receptors (Psychology of Sensations)-
The stimuli in the form of various sensory experiences are
received by our sensory systems known as receptors.
External Receptors
External receptors are those sensory mechanisms that help us
contact the outer world, for example, eyes, ears, nose, tongue
and skin. The specific receptor cells for receiving the external
stimuli lie within these sensory systems.

21. Sense organs
 Our sense organs help in assimilating knowledge of the
world around us. Each of our sense organs has a distinct
function to perform.
 Sense organs consist of receptors, which are specialized
sensitive cells associated with endings of sensory nerve
fibers. These receptors are stimulated by objects outside
the body and by internal conditions.
 When the receptors are not functioning properly, they lead
to sensory defects or disorders—visual, auditory,
cutaneous, olfactory, gustatory and kinesthetic disorders.

22. Internal Receptors
Internal receptors are associated with the internal stimuli
present in our body. They are responsible for feelings of
pain, hunger or nausea. Another variety of these internal
receptors helps us in maintaining balance, bodily posture and
equilibrium and exercise control over the muscles.
Sensation
The functioning of the five senses is called sensation.
Sensations are purely the result of physical stimuli operating
on our nervous system.

23. Sensory experience

24. Effectors (Muscular and Glandular Controls of Behavior)
Effectors are termed as the organs of responses. What is
received through the sensory organs in the form of sensory
input is responded through bodily reactions and motor
activities carried out through muscles and glands,
particularly the hormones secreted by the ductless glands,
which are responsible for most of our behavior patterns. The
underactivity or overactivity of these glands, causes
deficiency or excess of hormonal secretion. This affects the
entire personality makeup of the individual.
Muscles
Our behavior and activity involves movement of different
parts of our body. Muscles helps the organism to carry out
motor activities in order to respond to various stimuli.

25. There are mainly three types of muscles, viz. smooth
muscles, cardiac muscles and skeletal muscles.
 Smooth muscles are primarily concerned with the process
of digestion, excretion and blood circulation..
 Cardiac muscles function smoothly in a rhythmic fashion,
but when one is emotionally upset, their normal
functioning is disturbed causing heart trouble.
 Skeletal or striped muscles enable the individual to
perform voluntary motor activities ranging from walking
to the fine psychomotor skills like typing, etc.

26. Glands
Glands play an important role in human behavior. They also
assist in the digestion of food, elimination of waste products,
production and prolongation of emotional states and
regulation of metabolism of the body. There are two types of
glands:
1.Duct glands
2.Ductless or endocrine glands
Duct glands release their chemical secretion through little
ducts or tubes into the body cavities or on the surface of the
body.

27. Some of the duct glands are:
Salivary glands, Gastric glands, Sweat glands, Lacrimal
glands, Kidneys.
The duct glands either become overactive or underactive,
under the influence of emotions. There is a close and intimate
connection between human behavior and the secretions of
duct glands.
Ductless or endocrine glands secrete chemical substances
called hormones. The hormones are released into the blood
stream and are carried to all parts of the body. They play a
vital role in the determination of human personality. They
affect the development of the body, general metabolism,
mental development, development of secondary sex
characteristics and emotional behavior.

28. Endocrine
glands

29. Connectors
Connectors or adjusters help in regulating, controlling or
coordinating the activities of receptors and effectors. The
ability to play a piano, drive a car or hit a tennis ball
depends on muscle coordination. It is necessary for the
body to provide messages to the muscles to coordinate.
These messages are passed through specialized cells called
“neurons”.

30. Structure of the
neuron

31.  A nerve cell with all its branches is called a neuron. These
are the basic elements of the nervous system.
 A neuron has a nucleus, a cell body and a cell membrane
to enclose the whole cell. There are tiny fibers extending
out from the 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 the axon.

32.  A group of axons, bundled together like parallel wires in an
electrical cable, is referred to as a nerve.
 The axon (but certainly not all of them) is surrounded by a
fatty covering called the ‘myelin sheath’. It serves to
increase the velocity, with which the electrical impulses
travel through the axons.

33. Functions of neurotransmitters
Neurotransmitter Function
Acetylcholine Regulates muscle movement and
cognitive functioning
Glutamate Helps in memory process
Gamma aminobutyric acid
(GABA)
Moderates eating, aggression and sleeping
Dopamine
Regulates movements and coordination,
emotions and voluntary decision-making
ability. Deficiency of dopamine causes
Parkinson’s disease, overproduction
causes mental disorders like
schizophrenia
Serotonin Regulates sleep, eating, mood and pain
Endorphins Reduces pain and pleasurable feelings

34. NERVOUS SYSTEM
The nervous system is the master controlling,
communicating and regulatory system in the body. Nervous
system controls and coordinates all essential functions of the
human body. It is the center of all mental activity including
thought, learning and memory. Together with the endocrine
system, the nervous system is responsible for regulating and
maintaining homeostasis.

36. BRAIN

37. CEREBRUM
 CEREBRUM is the largest part
of brain
 Cerebrum consists of two
hemispheres namely right and
left hemispheres.
 Each hemisphere has 4 lobes
1.Frontal lobe
2.Temporal lobe
3.Parietal lobe
4.Occipital lobe

38. Lobe Function
Occipital Visual processing
Parietal Movement, orientation,
calculation, recognition
Temporal Sound and speech
processing, aspects of
memory
Frontal Thinking, conceptualization,
planning

39. THALAMUS- situated at the base of the cerebrum.
It has some control over the autonomic nervous system and also
plays a role in the control of sleep and alertness.
HYPOTHALAMUS- lies below the thalamus. It exerts a key
influence on all kind of emotional as well as motivational
behavior. Centers in the hypothalamus have control over the
important body processes like eating, drinking, sleeping,
temperature control and sex. It also has control over the
activities of pituitary gland.
MID BRAIN- is a short-constricted segment of brain which
forms a connection between cerebrum and other parts of brain.

40. HINDBRAIN-is composed of three structures the medulla, pons
and cerebellum.
‘Medulla’ controls breathing and many important reflexes, such
as those that help us to maintain our upright postures. It also
regulates the highly complex processes like digestion,
respiration and circulation.
The ‘pons’ assist in breathing, transmitting impulses from the
cerebellum to the higher brain regions and in coordinating the
activities of both sides of the brain.
‘Cerebellum’ is responsible for body balance and the
coordination of body movements like dancing, typing, playing,
etc.

42. Spinal cord works as a channel of communication from and
to the brain. It is a rope-like structure, made up of long
round nerve fibers. It also works as an organ for effective
reflex actions like withdrawal of the hand when something
is hot. These reflex actions are almost automatic in nature.

43. Importance of knowledge of the Nervous System and
Glands to a Nurse-
 It helps the nurse to understand the physiological basis
of patient behavior.
 It helps the nurse to understand how glandular secretions
influence personality.
 It helps the nurse to understand the various diseases of
nervous system and glands and their effect on human
behavior.