Chapter 1.5 Perception and Interaction PDF

CHAPTER 5- Perception and interaction 1.5.1. Scope: Organisms interact and respond to the changes that occur in their environment in order to survive. Central Nervous System (CNS) coordinates the responses shown by an organism. Receptors sense the changes in the surrounding (stimuli) and generate el...

CHAPTER 5- Perception and interaction 1.5.1. Scope: Organisms interact and respond to the changes that occur in their environment in order to survive. Central Nervous System (CNS) coordinates the responses shown by an organism. Receptors sense the changes in the surrounding (stimuli) and generate electrical impulses (sensory) which are transmitted to the CNS. CNS modulates and generates a new impulse (motor) which determines the nature of the response that an organism exhibits. 1.5.2 Scope: Neurons have electrolytes (Na+, K+, etc.) on the inner and outer sides of their membranes. The distribution of electrolytes determines the potential difference of the membrane. On being stimulated, the pattern of distribution keeps changing, allowing transmission of the impulse. During rest, the membrane is in a polarised state having more positive charge outside the membrane and less inside. During the generation of transmission of impulse, the potential difference is reversed (action potential) and the membrane is depolarised. The transmission of impulses is a result of the movement of electrolytes in and out of the nerve fibres. The electrical state of a neuron keeps changing during impulse conduction 1.5.3. Scope: Artificial Intelligence (AI) is a field of computer science, associated with enabling machines to work in a similar manner as the human nervous system. These systems are designed to perform tasks that require human intelligence. Through this, robots/ machines are employed to work in situations that are not usually possible for humans. The working principle of AI-based systems is similar to that of the human nervous system. 1.5 A. How do organisms respond to change in the environment? Organisms need to detect and respond to changes in their internal and external environment. This is because the conditions inside our body must be carefully controlled for it to function effectively and survive. How does the nervous system help us respond? The nervous system takes in information through our senses, processes the information and triggers reactions, such as making our muscles move or causing us to feel pain. For example, if you touch a hot plate, you reflexively pull back your hand and your nerves simultaneously send pain signals to your brain. Neural system provides an organized network of point to point connection for quick coordination. The endocrine system provides chemical integration through hormones. All living organisms have a mechanisms to identify the changes in in the environment and respond to the changes.  Changes in the environment is called stimuli.  There are specific cells (organs) in the organisms which have ability to respond to the environmental  changes—receptors or sense organs  Therefore, mechanism takes place to respond.  Reaction shown by a living organism (effector) to a stimulus=response. Control systems consists of: 1. Receptor—cells, tissues, organs or organ system, which detect stimuli (changes in the environment). 2. Coordination centre—CNS (brain and spinal cord) or pancreas, which receives and Process /interpret information/stimulus from receptors around the body. 3. Effectors—muscles or glands, which bring about responses such as muscle contractions or hormone release. For example: 1. Closing of eyes when light falls on them. CHAPTER 5-PERCEPTION AND INTERACTION/SC 1  2. Withdrawal of hand immediately when it touches any hot objects. 3. Salivating while we think or see the delicious food. 4. Running away while we see tiger or snake. How it works?  By coordinator and interaction—it carries impulse to and from CNS.  Receptors (cells in sense organs) are structures at ends of the nerve fibres that collects the information to be conducted by the nerves and send it to the CNS. Nerves in turn conduct these impulses from the CNS and send it to the effectors which are muscles or glands which work in response to the stimulus received from the brain.  In man and other vertebrates, the physiological functions are coordinated by both the nervous and endocrine systems. [Neuro-endocrine system].  The system that receives the stimulus transmits it to other parts of the body and the corresponding effect shown is known as a Nervous System.  The nervous system performs three basic functions; receives stimuli through sensory neurons from internal and external environment and passes to the brain; where the input stimuli is processed and then response is given back to the body parts through motor neurons. What is Coordination? The ability to regulate various organs of body in an organism for their smooth, efficient and coordinated working is termed as coordination. Response to any stimulus are definite, highly controlled and coordinated. They involve association, synchronization, integration and control of various physiological activities occurring in various body parts. Coordination between stimulus & response (between receptors and effectors) Coordination and integration between various organs and systems. Two systems for coordination in multicellular organisms: 1. Nervous system—it forms an organized network of nerve cells or neurons. 2. Endocrine system—it provides a wider chemical integration with help of chemicals, called hormones or chemical messenger or information molecules. Nervous system + endocrine system=collectively form neuro-endocrine system. Why coordination? It enables to body to give quick responses to harmful stimuli (to minimize the damage to body). Prevent overloading of brain. It allows animals including human to adjust properly to both external and internal stimuli, to escape from unfavorable environment. To maintain a constant internal environment (homeostasis) CHAPTER 5-PERCEPTION AND INTERACTION/SC 2