Unit 2 - Biology of Behavior - PSYC 310

Unit 2 - Biology of Behavior PSYC 310 1  Introduction 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 a...

Unit 2 - Biology of Behavior PSYC 310 1  Introduction 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 and the mind. PSYC 310 2  Body-mind relationship— modulation process in health and illness ❖ Psychology studies human behavior, which involves both the body and the mind ❖ Our nervous system and glands, which are an important part of our body are responsible for our ways of thinking, feeling and doing. ❖ All behaviors have an anatomical and physiological basis. Physiological structures, body fluids, chemicals and mechanical events, all influence both our overt behavior and our feelings and experiences. ❖ Our mental functions like strong feelings, emotions, attitudes, motives, thinking, etc. influence our bodily activities and processes. ❖ Emotions are combination of bodily responses and mental processes. PSYC 310 3  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 full influence on one’s personality, resulting in lethargy, nervous tension, etc. Physical fatigue affects our mood and reduces our motivation, interest and concentration. Brain injury affects many psychological functions. At the same time well developed brain leads to the development of better intellectual functioning. PSYC 310 4  Effects of Mental Conditions on Bodily Functioning Unpleasant emotions like fear, anger and worry cause irritability, insomnia, headache, etc. Mental processes are intimately connected to brain or cortical processes, e.g. depression affects thinking and memory. Emotional conflicts are responsible for peptic ulcer, ulcerative colitis, etc. Deep thinking and concentration can cause physical strain Unconscious motivation and conflicts gives rise to many physical complaints and neurotic disorders like conversion disorders. PSYC 310 5  Genetics and Behavior: Heredity and Environment 6  Heredity Heredity is considered as “the sum total of inborn individual traits”. Biologically, defined as - “the sum total of traits potentially present in the fertilized ovum”. According to Douglas and Holland “one’s heredity consists of all the structures, physical characteristics, functions or capacities derived from parents, other ancestry or species”. 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 PSYC 310 7  Environment After conception, how he develops is the outcome of the interaction between his heredity 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 fertilization of the ovum Therefore, from the environmental point of view, not only what happens after birth is important, but what goes on inside the womb of the mother after conception is equally significant. PSYC 310 8 Types of Environment Intercellular environment Intrauterine environment External environment PSYC 310 9 Intercellular environment It relates to embryonic development. The cytoplasm is in the intercellular environment, because the genes surrounded by it are influenced by and in turn influence its characteristics. Endocrine glands and hormones also produce intercellular influence. Many congenital deformities are the result of overactive or underactive endocrine function PSYC 310 10  Intrauterine environment It shelters the baby during prenatal life. In the womb the growing organism is surrounded by amniotic fluid and attached to the mother by the umbilical cord. Thus, growth of the embryo depends on the nourishment provided by the mother. The physiological and psychological states of the mother during pregnancy, her habits and interests, etc. all influence the development of the child. PSYC 310 11 External environment It can be divided into three kinds: Physical environment Biological environment Psychosocial environment PSYC 310 12 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. 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. PSYC 310 13 Psychosocial 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 are also included in this environment. 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. PSYC 310 14  Brain and behavior: Nervous system, neurons and synapse 15  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 proper growth and development of nerve tissues and nervous system as a whole - helps in the task of proper intellectual development. 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 due to secretion of hormones by some glands. PSYC 310 16 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 and endocrine glands, called effectors. 3. The nervous system known as the connecting or integrating mechanism. PSYC 310 17 Receptors (Psychology of Sensations) Behavior in all its forms and shapes has definitely a biological or physiological base. The behavior is based on the various stimuli present in the external environment and lying within our body. The stimuli in the form of various sensory experiences are received by our sensory systems known as receptors (External & Internal). 1. External Receptors These are those sensory mechanisms that help us make contact with the outer world, for example, eyes, ears, nose, tongue and skin. The specific receptor cells for receiving the external stimuli lie within these PSYCsensory 310 systems. 18 2. 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 also exercise control over the muscles. PSYC 310 19  Effectors are termed as the organs of responses. What is received through the sensory organs in the Effectors form of sensory input is responded through bodily (Muscular and reactions and motor activities carried out through Glandular muscles and glands, particularly the hormones Controls of secreted by the ductless glands, which are Behavior) 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. PSYC 310 20 Cont.. Muscles Our behavior and activity involves movement of different parts of our body. Muscles help the organism to carry out motor activities in order to respond to various stimuli. ❑ Cardiac muscles function smoothly in a rhythmic fashion, but when one is emotionally upset, their normal functioning is disturbed causing heart trouble 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: Duct glands Ductless or PSYC endocrine 310 glands 21  Duct glands These release their chemical secretion through little ducts or tubes into the body cavities or on the surface of the body. 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. PSYC 310 22  Ductless or endocrine glands These 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. PSYC 310 23 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’. PSYC 310 24  Neuron 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 There are three types of neurons. 1. Sensory neurons—they help in the process of sensation and perception. 2. Motor neurons—they are responsible for physical movements and activation of glands. 3. Interneurons or association neurons—they carry signals in the form of memories and thoughts and add reflex or automatic activities. PSYC 310 25  Neurotransmitters play an essential function in the role of human emotion and behavior. Neurotransmitters These are chemicals that convey information across synaptic cleft to neighboring target cells. Deficiency or an excess of a neurotransmitter can produce severe behavioral disorders. PSYC 310 26  Nervous System 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. PSYC 310 27  Central Nervous System Central nervous system (CNS) consists of brain and the spinal cord, which act as the integrating and command centers of the nervous system. They interpret incoming sensory information and issue instructions based on past experience and current conditions. Brain is composed of three main divisions: the forebrain, midbrain and hindbrain PSYC 310 28  Forebrain - Thalamus, Hypothalamus, Limbic system and the Cerebrum 1. All sensory impulses pass through from thalamus to the higher centers, therefore it is usually known as the relay station. In addition, the thalamus has some control over the autonomic nervous system and also plays a role in the control of sleep and alertness. 2. Hypothalamus lies below the thalamus. Centers in the hypothalamus have control over the important body processes like eating, drinking, sleeping, temperature control and sex. 3. The limbic system often called the emotional brain, functions in emotional aspects of behavior related to survival, memory, smell, pleasure and pain, rage and aggression, affection, sexual desire etc. PSYC 310 29  Hindbrain Hindbrain is composed - medulla, pons and cerebellum. 1. ‘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. 2. 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. 3. ‘Cerebellum’ is responsible for body balance and the coordination of body movements like dancing, typing, playing, etc PSYC 310 30 Lobes of brain and their functions PSYC 310 31 Importance of knowledge of the Nervous System and Glands 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. PSYC 310 32  Reference Sreevani, R. Psychology for nurses. Jaypee Brothers,Medical Publishers Pvt. Limited. page no 14-29 PSYC 310 33