PSY 103_PRELIM.pdf

 Table of Contents Module 1................................................................................................... 5 Overview of Physiological Psychology........................................................... 5 Learning Outcomes...............

 Table of Contents Module 1................................................................................................... 5 Overview of Physiological Psychology........................................................... 5 Learning Outcomes..........................................................................................5 Lesson 1. History of Physiological Psychology................................................................... 5 Lesson 2. Relating Brain and Behavior............................................................................ 9 References..................................................................................................... 11 Assessment Task 1-1...................................................................................... 12 Assessment Task 1-2...................................................................................... 14 Module 2................................................................................................ 15 Neurons and Synapses.............................................................................. 15 Learning Outcomes........................................................................................ 15 Lesson 1. Structure of a Neuron.................................................................................... 15 Lesson 2. Functions of a Neuron................................................................................... 16 Lesson 3. Types of Neurons........................................................................................... 17 Lesson 4. Stages of Action Potential............................................................................... 18 Lesson 5. Neural Network.............................................................................................. 19 Lesson 6. Neurotransmitters......................................................................................... 19 References..................................................................................................... 22 Assessment Task 2-1...................................................................................... 23 Assessment Task 2-2...................................................................................... 24 Assessment Task 2-3...................................................................................... 26 Module 3................................................................................................ 27 Nervous System and the Brain................................................................... 27 Learning Outcomes........................................................................................ 27 Lesson 1. The Development of Nervous System Across Human Lifespan......................... 27 Lesson 2. Functions of the Nervous System................................................................... 28 Lesson 3. Divisions of the Nervous System..................................................................... 30 Lesson 4. Basic Cells of the Nervous System.................................................................. 31 Lesson 5. The Central Nervous System.......................................................................... 32 Lesson 6. The Peripheral Nervous System...................................................................... 34 References..................................................................................................... 36 Assessment Task 3-1...................................................................................... 37 2  Table of Figures Figure 2. 1 Parts of Neurons................................................................... 15 Figure 2. 2 Neurons................................................................................ 18 Figure 3. 1 Brain Functions.................................................................... 33 Figure 3. 2 Nervous System.................................................................... 34 3 Course Code: PSY 212 Course Description: The physiological approach to studying human behavior. Basic concepts and findings in neuroscience with special emphasis on brain-body relationship, brain-behavior relationship, and mind-behavior relationship are treated in the course. This course explores the trends in physiological psychology, a rapidly growing and changing field that deals with the relationship between physiology and behavior. It considers the physiological correlates of emotions and how emotions are related to specific kinds of brain activity, the plasticity of the nervous system as it relates to learning and memory. Course Intended Learning Outcomes (CILO): At the end of this course, the students should be able to: 1. Understand and demonstrate the structure of the brain and its effect to the behavior of the person 2. Demonstrate competency in physiological and neuronal processes involved in physical and psychological phenomena 3. Identify and critically evaluate how topics in physio psychology have been and are being researched 4. Identify and evaluate the interaction between biology and culture; 5. Apply physio psychological concepts and theories to everyday life and personal experiences. Course Requirements: Class Standing - 60% Major Exams - 40% _________ Periodic Grade 100% Final Grade = Total CS + Final Exam x 70% + 30% of the Midterm 4  Module 1 Overview of Physiological Psychology Learning Outcomes At the end of this period, students should be able to: Understand the scope of physiological psychology. Expand knowledge on its relation to psychology. Identify key note on how physiological psychology started Lesson 1. History of Physiological Psychology Early Ancestors One million years ago man valued brain, and knew that injury to it caused death. First brain surgery is trephination took place around 7000 BCE during Neolithic times Trephination – a surgical procedure in which a circular piece of bone is drilled and excised, most commonly from the human skull. Ancient Chinese In 2700 BCE, Shen Nung originated acupuncture based on Yin-Yang philosophy. Acupuncture was derived from Taoist traditions that were even older (8000 years ago) Ancient Egyptians Called the Edwin Smith Surgical Papyrus, they were first written account of brain in 1700 BCE, based on text that was 3000 BCE old. This account describes 28 cases of brain, skull and spinal injuries. Hippocrates Studied brain injured patients (gladiators), and noted that brain was the seat of our joys, pleasure, and sorrows etc. And our sensations and intelligence. Greek Philosophers Plato correctly identified mind in the brain. 5  However, his student Aristotle believed that mind was in the heart. Brain was merely a radiator to cool the blood. Roman Physician Galen (Jalinoos, 129-199) a prominent Roman surgeon, agreed with Hippocrates on brain as the seat of mind. Carried out dissections, and found cerebrum to be soft and cerebellum hard. Also discovered fluid-filled ventricles, which he thought (cerebrospinal fluid) was used to communicate. Muslim Physicians Ibn Zakariya al-Razi (Rhazes), a Persian physician, criticized Galen on his theory bodily humors. Describes seven cranial nerves and 31 spinal nerves in Kitab al-Hawi Fil-Tibb. Al-Haytum Al-Haytum (Alhazen) wrote a seven-volume book on optics called Kitab-al-Manazir. Correctly identified light as an external source for vision and dispelled Empedocles ideas of visual ray. Al-Zahrawi Al-Zahrawi (Abulcasis), an Arab surgeon from Spain, described several surgical treatments for neurological disorders. Wrote Kitabal-Tasrif, a thirty-volume encyclopedia of medical practices. Ibn-i-Sina Ibn-i-Sina (Avicenna), also called the Prince of Medicine, wrote Al-Qanoon fil-Tibb (The Canon of Medicine) In the text, he talked about perception, imagination, and generation of ideas. Rene Descartes Like Plato, he believed that mind possessed innate ideas, and proposed the mind-body dualism interacting at the pineal gland. 6  Descartes described reflex action as a basis of understanding behavior from a neuroscientific view. Nerves Luugi Galvani (1737-1798) and Emil Du Bois-Reymond (1818-1896) showed that electrical current would twitch muscles, and the brain generated electricity. Charles Bell (1774-1842) and Francois Magendie (1783-1855) showed spinal roots carried messages in different directions. Specific Nerve Energies Johannes Muller (1801-1858) proposed that the nature of a sensation depends on sensory fibers stimulated, not on how fibers are stimulated His student, H. Hemholtz (1821-1894), measured the speed of nerve conduction. Neuron Doctrine Camillo Golgi (1843-1926) believed that neurons connected in a syncitium - A large cell- like structure that forms when many cells fuse together. Ramon Y Cajal (1852-1934) believed that neurons are separate and communicate through gaps. This came to be known as the neuron doctrine or the concept that the nervous system is made up of discrete individual cells Synapse Sir Charles Sherrington (1857-1952) studied reflex action in dogs. Based on his behavioral experiment, he inferred about synaptic transmission. He named the gap Cajal pointed out as synapse. Brain Regions Pierre Flourens (1774-1867) conducted many brain ablation experiments and found that cerebellum played an important role in coordinated movements. “Skull Bumps” Franz Joseph Gall (1758-1828) studies skull bumps and proposed modularity of brain. He also stated that different parts of brain performed different functions. 7  Phrenology refers the study of the conformation of the skull as indicative of mental faculties and traits of character. Speech Area Paul Broca (1824-1880) studied patient Tan after his death and found an area in the brain that was involved with speech production which later called as Broca’s area. Speech Comprehension Just as Broca had shown speech production area in the brain, Carl Wernicke (1848-1904) identified speech comprehension area which is called as Wernicke’s area. Brain Area Korbinian Brodmann (1868-1918) divide the brain into many distinct areas or regions and delineated their role in behavioral function. Localization of Function Karl Lashley (1868-1918) and Shepherd Franz (1874-1933) were critics of localization of function in the brain. Lashley’s showed that a number of behaviors like learning and memory were not localized in particular regions of the brain. Reward Centers James Olds (1922-1976) claimed that electrical stimulation of the brain evokes emotional responses in animal. He also stated that reward centers are located in the brain. Electrical Brain Stimulation Canadian neurosurgeon, Wilder Penfield (1891-1976), stated that electrical stimulation of the human brain evokes localized epileptic foci. He also stated that stimulation of specific areas of the brain evoked specific memories He also described sensory and motor cortex in the human brain. Brain Lateralization 8  Roger Sperry (1913-1994) carried experiments to discover left and right brain hemispheric specialization Michael Gazzaniga (1939-present), Sperry’s student, conducts research on how the brain enables mind. Biology of Memory Mortimer Mishkin (1926-2021) uses multidisciplinary approach to investigate the neurobiological mechanisms underlying learning and memory in both humans and nonhuman primates. Brain lesions specially designed to study behavioral learning and cognitive memory tasks. Christopher Koch (1956-present) Koch is promoting the study of consciousness through the use of modern tools of neurobiology. His primary collaborator in this endeavor was the late Francis Crick Lesson 2. Relating Brain and Behavior One of the most important and interesting discoveries about the brain has been its plasticity. In short, the brain can reorganize itself as a consequence of experience or damage. For example, taxi drivers have a larger part of the brain that appears to be related to navigation skill than non-taxi driving adults, and the amount of brain area is related to experience as a driver. Sometimes, the plasticity can be dramatic. In a feat of nearly Frankensteinean proportions, researchers were able to rewire the brains of ferrets so that visual information was sent to the brain area that was supposed to process sounds, and vice versa. The ferrets’ brains were able to reorganize so that the animals were able to function correctly. Although no one has attempted such a dramatic demonstration with a human brain, there are striking examples of human plasticity as well. Perhaps the most amazing example is when an operation called a hemispherectomy is performed. This operation, the actual removal of one hemisphere (half) of a brain, has been used on very rare occasions as a treatment for severe and degenerative seizures. Research has shown that the operation can substantially reduce symptoms, and patients can function quite well, in many cases as well as people who have intact brains. Recent research compared brain scans of six hemispherectomy patients to a large group 9 of healthy controls. They found that several functional areas of the brain had stronger interconnections for the 6 patients than for the normal controls, as if their brains compensated for the missing halves by increasing connections in the remaining hemisphere. When you first look at a brain, you see a lumpy, light grayish-brown, wrinkled mass, with few discernible parts. At first, then, it seems plausible that the brain might be infinitely plastic. A great many people do believe that the brain can basically reorganize itself without limit. With a little careful examination, however, you can begin to notice that there are separate sections. For example, on the surface of the brain, some of the wrinkles look larger than others, and some of the lumps are more pronounced than others. These separate areas are recognizable on any brain, and they are completely unrelated to any damage or experience. So, without denying that the brain can change itself, you must realize that the brain has a very intricate structure, very specific parts biologically determined to fulfill specific functions. Just as a skilled radiologist can recognize what appear to the untrained eye to be unintelligible specks on an x-ray of the body, you can learn to recognize these different areas in the brain. If you intend to be a neuroscientist, you’ll definitely need to acquire this skill. It is also handy for psychologists, given today’s emphasis on biopsychology. But even if you never have a professional need to recognize the brain’s features, we think that you will find them interesting. And although we hope you never have this experience, somebody you know might someday have a brain disorder or injury that will make your study of the brain’s geography entirely relevant. 10  References https://studylib.net/doc/25591870/history-of-physiological-psychology https://www.osmosis.org/answers/trephination#:~:text=What%20is%20trephination%3F, commonly%20from%20the%20human%20skull https://clinicalinfo.hiv.gov/en/glossary/syncytium https://en.wikipedia.org/wiki/Neuron_doctrine https://www.britannica.com/topic/phrenology Gray, K.,Arnott-Hill, E., & Benson, O. (2020). Introduction to Psychology 1st Ed. Cognella Academic Publishing 11  Assessment Task 1-1 Answer the following question. Explain your answers in 3-5 sentences. 1. What is the value of studying the history of physiological psychology? Is it a waste of time? ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ________________ 2. On your own opinion, how do you think our brain relates to our behavior? Explain your answer by citing example/s. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ________________ 12 3. As psychology students, do you think studying the physiological aspect of human behavior will help you with your chosen path? ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ________________ 13  Assessment Task 1-2 Matching Type. Match the statements from Column A to the corresponding answer on Column B Column A Column B 1. The nature of a sensation depends on sensory fibers a) Paul Broca stimulated. 2. Wrote a seven-volume book on optics called Kitab-al- b) James Olds Manazir. 3. Broca’s area c) Franz Joseph Gall 4. Wernicke’s area d) Christopher Koch 5. Phrenology e) Carl Wernicke 6. Studied consciousness through the use of modern tools f) Johannes Muller of neurobiology. 7. Carried experiments to discover left and right brain g) Wilder Penfield hemispheric specialization 8. Electrical stimulation of the brain evokes emotional h) Francis Crick responses in animal. 9. He is the primary collaborator of Christopher Koch i) Roger Sperry 10. Electrical stimulation of the human brain evokes j) Al-Haytum localized epileptic foci. 11. Called the Prince of Medicine k) Pierre Flourens 12. Arab surgeon who described several surgical treatments l) Al-Zahrawi for neurological disorders. 13. Describes seven cranial nerves and 31 spinal nerves in m) Ibn Zakariya al-Razi Kitab al-Hawi Fil-Tibb 14. Found that cerebellum played an important role in n) Ibn-i-Sina coordinated movements. 15. A surgical procedure in which a circular piece of bone is o) Trephination drilled and excised, most commonly from the human skull. 14  Module 2 Neurons and Synapses Learning Outcomes At the end of this period, students should be able to: Detail the structures and functions of each type of neuron. Outline the steps of the process of communication among neurons. Summarize the importance of the synapse to neurotransmitter communication. Explain the role of neurotransmitters in the communication process between neurons. Explain the different theories of how neural networks operate in the body Lesson 1. Structure of a Neuron A neuron is a brain cell with two specialized extensions. One extension is for receiving electrical signals, and a second, longer extension is for transmitting electrical signals. Additionally, neurons form a vast, miniaturized informational network that allows us to receive sensory information, control muscle movement, regulate digestion, secrete hormones, and engage in complex mental processes such as thinking, imagining, dreaming, and remembering. 2 1 5 3 6 4 Figure 2. 1 Parts of Neurons Source: https://sciencetrends.com/wp-content/uploads/2019/05/neuron-featured.png 1. The cell body (or soma) is a relatively large, egg-shaped structure that provides fuel, manufactures chemicals, and maintains the entire neuron in working order. 15  2. Dendrites are branchlike extensions that arise from the cell body; they receive signals from other neurons, muscles, or sense organs and pass these signals to the cell body. 3. The axon is a single threadlike structure that extends from, and carries signals away from, the cell body to neighboring neurons, organs, or muscles. 4. The myelin sheath looks like separate tube-like segments composed of fatty material that wraps around and insulates an axon. The myelin sheath prevents interference from electrical signals generated in adjacent axons. 5. End bulbs or terminal bulbs look like tiny bubbles that are located at the extreme ends of the axon’s branches. Each end bulb is like a miniature container that stores chemicals called neurotransmitters, which are used to communicate with neighboring cells. 6. The synapse is an infinitely small space (20–30 billionths of a meter) that exists between an end bulb and its adjacent body organ (heart), muscles (head), or cell body. Lesson 2. Functions of a Neuron Neurons lie adjacent to each other but are not connected. There is a tiny gap between neurons called a synapse. The function of a neuron is to transmit nerve impulses along the length of an individual neuron and across the synapse into the next neuron. The electrical signals transmitted by neurons are called action potentials. The electrical signal needs to cross the synaptic gap to continue on its journey to or from the CNS. This is done using chemicals that diffuse across the gap between the two neurons. These chemicals are called neurotransmitters. During synaptic transmission, the action potential (an electrical impulse) triggers the synaptic vesicles of the pre-synaptic neuron to release neurotransmitters (a chemical message). These neurotransmitters diffuse across the synaptic gap (the gap between the pre- and post-synaptic neurons) and bind to specialized receptor sites on the post-synaptic neuron. This will then trigger an electrical impulse in the adjacent cell. The central nervous system, which comprises the brain and spinal cord, and the peripheral nervous system, which consists of sensory and motor nerve cells, all contain these information-processing neurons. 16 Lesson 3. Types of Neurons There are three types of neurons. These are the following: Sensory neurons These are nerve cells that are activated by sensory input from the environment. E.g., When you touch a hot surface with your fingertips. The sensory neurons will be the ones firing and sending off signals to the rest of the nervous system about the information they have received. Most sensory neurons are pseudounipolar, which means they only have one axon which is split into two branches. Motor neurons These are part of the central nervous system (CNS) and connect to muscles, glands and organs throughout the body. These neurons transmit impulses from the spinal cord to skeletal and smooth muscles (such as those in your stomach), and so directly control all of our muscle movements. There are in fact two types of motor neurons: those that travel from spinal cord to muscle are called lower motor neurons, whereas those that travel between the brain and spinal cord are called upper motor neurons. Motor neurons have the most common type of ‘body plan’ for a nerve cell - they are multipolar, each with one axon and several dendrites. Interneurons As the name suggests, interneurons are the ones in between - they connect spinal motor and sensory neurons. As well as transferring signals between sensory and motor neurons, interneurons can also communicate with each other, forming circuits of various complexity. They are multipolar, just like motor neurons. 17  Figure 2. 2 Neurons https://upload.wikimedia.org/wikipedia/commons/b/b8/Figure_35_01_04.jpg Lesson 4. Stages of Action Potential Action potential is a brief reversal of membrane potential where the membrane potential changes from -70mV to +30mV. When the membrane potential of the axon hillock of a neuron reaches threshold, a rapid change in membrane potential occurs in the form of an action potential. The action potential has three main stages. The depolarization, also called the rising phase, is caused when positively charged sodium ions (Na+) suddenly rush through open voltage-gated sodium channels into a neuron. As additional sodium rushes in, the membrane potential actually reverses its polarity. During this change of polarity, the membrane actually develops a positive value for a moment (+40 millivolts). The second stage is repolarization or falling phase is caused by the slow closing of sodium channels and the opening of voltage-gated potassium channels. As a result, the membrane permeability to sodium declines to resting levels. As the sodium ion entry declines, the slow voltage-gated potassium channels open and potassium ions rush out of the cell. This expulsion acts to restore the localized negative membrane potential of the cell. Lastly, Hyperpolarization is a phase where some potassium channels remain open and sodium channels reset. A period of increased potassium permeability results in excessive potassium efflux before the potassium channels close. This results in hyperpolarization as seen in a slight dip following the spike. 18 Lesson 5. Neural Network The brain is principally composed of about 10 billion neurons, each connected to about 10,000 other neurons. Each of the yellow blobs in the picture above are neuronal cell bodies (soma), and the lines are the input and output channels (dendrites and axons) which connect them. Each neuron receives electrochemical inputs from other neurons at the dendrites. If the sum of these electrical inputs is sufficiently powerful to activate the neuron, it transmits an electrochemical signal along the axon, and passes this signal to the other neurons whose dendrites are attached at any of the axon terminals. These attached neurons may then fire. It is important to note that a neuron fires only if the total signal received at the cell body exceeds a certain level. The neuron either fires or it doesn't, there aren't different grades of firing. So, our entire brain is composed of these interconnected electro-chemical transmitting neurons. From a very large number of extremely simple processing units (each performing a weighted sum of its inputs, and then firing a binary signal if the total input exceeds a certain level) the brain manages to perform extremely complex tasks. This is the model on which artificial neural networks are based. Thus far, artificial neural networks haven't even come close to modeling the complexity of the brain, but they have shown to be good at problems which are easy for a human but difficult for a traditional computer, such as image recognition and predictions based on past knowledge. Lesson 6. Neurotransmitters There are several different types of neurotransmitters released by different neurons, and we can speak in broad terms about the kinds of functions associated with different neurotransmitters. Much of what psychologists know about the functions of neurotransmitters comes from research on the effects of drugs in psychological disorders. Psychologists who take a biological perspective and focus on the physiological causes of behavior assert that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems. In this perspective, psychotropic medications can help improve the symptoms associated with these disorders. Psychotropic medications are drugs that treat psychiatric symptoms by restoring neurotransmitter balance. 19  Major Neurotransmitters and How They Affect Behavior Neurotransmitter Involved in Potential Effect on Behavior Acetylcholine Muscle action, memory Increased arousal, enhanced cognition Beta-endorphin Pain, pleasure Decreased anxiety, decreased tension Dopamine Mood, sleep, learning Increased pleasure, suppressed appetite Gamma-aminobutyric acid Brain function, sleep Decreased anxiety, (GABA) decreased tension Glutamate Memory, learning Increased learning, enhanced memory Norepinephrine Heart, intestines, alertness Increased arousal, suppressed appetite Serotonin Mood, sleep Modulated mood, suppressed appetite Table 2. 1 Major Neurotransmitters and How They Affect Behavior Psychoactive drugs can act as agonists or antagonists for a given neurotransmitter system. Agonists are chemicals that mimic a neurotransmitter at the receptor site and, thus, strengthen its effects. An antagonist, on the other hand, blocks or impedes the normal activity of a neurotransmitter at the receptor. Agonist and antagonist drugs are prescribed to correct the specific neurotransmitter imbalances underlying a person’s condition. For example, Parkinson’s disease, a progressive nervous system disorder, is associated with low levels of dopamine. Therefore, dopamine agonists, which mimic the effects of dopamine by binding to dopamine receptors, are one treatment strategy. Certain symptoms of schizophrenia are associated with overactive dopamine neurotransmission. The antipsychotics used to treat these symptoms are antagonists for dopamine—they block dopamine’s effects by binding its receptors without activating them. Thus, they prevent dopamine released by one neuron from signaling information to adjacent neurons. In contrast to agonists and antagonists, which both operate by binding to receptor sites, reuptake inhibitors prevent unused neurotransmitters from being transported back to the neuron. This leaves more neurotransmitters in the synapse for a longer time, increasing its effects. Depression, which has been consistently linked with reduced serotonin levels, is commonly 20 treated with selective serotonin reuptake inhibitors (SSRIs). By preventing reuptake, SSRIs strengthen the effect of serotonin, giving it more time to interact with serotonin receptors on dendrites. Common SSRIs on the market today include Prozac, Paxil, and Zoloft. The drug Lysergic acid diethylamide (LSD) is structurally very similar to serotonin, and it affects the same neurons and receptors as serotonin. Psychotropic drugs are not instant solutions for people suffering from psychological disorders. Often, an individual must take a drug for several weeks before seeing improvement, and many psychoactive drugs have significant negative side effects. Furthermore, individuals vary dramatically in how they respond to the drugs. To improve chances for success, it is not uncommon for people receiving pharmacotherapy to undergo psychological and/or behavioral therapies as well. Some research suggests that combining drug therapy with other forms of therapy tends to be more effective than any one treatment alone 21  References Plotnik, R., & Kouyoumdjian, H. (2011). Introduction to Psychology 9th Ed. Wadsworth Cengage Learning Evans, O. G. (2023). An Easy Guide To Neuron Anatomy With Diagrams. Retrieved from https://www.simplypsychology.org/neuron.html https://qbi.uq.edu.au/brain/brain-anatomy/types-neurons https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiol ogy_(Boundless)/10%3A_Overview_of_the_Nervous_System/10.5%3A_Neurophysiology /10.5E%3A_The_Action_Potential_and_Propagation#:~:text=Key%20Points&text=The% 20action%20potential%20has%20three,depolarization%2C%20repolarization%2C%20a nd%20hyperpolarization Spielman, R., Jenkins, W., & Lovett, M. (2021). Psychology. BCcampus. https://opentextbc.ca/h5ppsychology/ https://cs.stanford.edu/people/eroberts/courses/soco/projects/neural- networks/Biology/index.html 22  Assessment Task 2-1 Name the basic parts of the neuron and explain the function of each in your own words. 3 4 2 1 5 6 Answer: 1. 2. 3. 4. 5. 6. 23  Assessment Task 2-2 Answer the following question. Explain your answers in 3-5 sentences. 1. Explain what is the functions of the neurons and how it transmits signals to other neurons. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ________________ 2. Differentiate the three types of neurons. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 24  ______________________________________________________________________________ ________________ 3. Explain what is action potential and the different stages of action potential. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ________________ 25  Assessment Task 2-3 Matching Type. Match the statements from Column A to the corresponding answer on Column B Column A Column B 1. Pain, pleasure a. Brain function, sleep 2. Mood, sleep, learning b. Antagonist 3. GABA c. Memory, learning 4. Glutamate d. Agonist 5. Heart, intestines, alertness e. Mood, sleep 6. Serotonin f. Beta-endorphin 7. Muscle action, memory g. SSRIs 8. Common treatment for depression h. Norepinephrine 9. Blocks or impedes the normal activity of a i. Acetylcholine neurotransmitter 10. Mimic a neurotransmitter j. Dopamine 26  Module 3 Nervous System and the Brain Learning Outcomes At the end of this period, students should be able to: Name the various parts of the nervous system and their respective functions. Analyze the functions of nervous system. Identify the role of cells in the nervous system. Determine the regions of the Brain. Compare and contrast Central and Peripheral Nervous System Lesson 1. The Development of Nervous System Across Human Lifespan Induction of the Neural Plate Occurs three weeks after conception Becomes recognizable as the neural plate – ectodermal tissue on the dorsal side of the embryo Has three layers – endoderm, mesoderm, ectoderm Stem cells – are cells that meets 2 criteria 1) can take the form of other cells 2) replicates Immature forms – no axons or dendrites Fuse together to form the neural groove Capacity for stem cells comes from a cell splitting into two daughter cells – one is a specified cell and one is a stem cell – can keep dividing until an error occurs (cancer) Neural Proliferation After the neural groove and neural tube is formed, cells begin to proliferate, meaning multiply Multiplying does not occur simultaneously Most occurs in the ventricular zone, the center of the plate The pattern in which neurons proliferate, occurs from chemical signals from the floor plate and the roof plate Migration and Aggregation Once cells have been created, cells migrate to their target location 27  Two major factors govern migration: Time and Location Two kinds of migration – radial (out) and tangential (right angle) Radial migration proceeds from the ventricular zone in a straight line outward toward the outer wall of the tube; Tangential migration occurs at a right angle to radial migration— that is, parallel to the tube’s walls. Two methods of migration – somal translocation and glial-mediated. Somal translocation – grow extensions Glial-mediated – glial cells form a wall and neurons move across this Aggregation forms an order after neurons have migrated Align themselves with other neurons that have migrated to the same locations Axon Growth and Synapse Formation Once neurons have migrated to their appropriate positions and aggregated into neural structures, axons and dendrites grow. At each growing tip of an axon or dendrite is an amoebalike structure called a growth cone which extends and retracts fingerlike cytoplasmic extensions called filopodia. In one study, Sperry cut the optic nerves of frogs, rotated their eyeballs 180 degrees– retinal ganglion cells regenerated (CH) Chemo affinity hypothesis – chemical signals bring neurons to specific locations. Neuron Death and Reorganization Neuron death is a natural and important process of neurodevelopment. If neuron death does not occur, cancer may occur. Passive cell death is called necrosis; active cell death is called apoptosis. Apoptosis is safer than necrosis. Necrotic cells break apart and spill their contents into extracellular fluid, and the consequence is potentially harmful inflammation. Lesson 2. Functions of the Nervous System The nervous system can also be divided on the basis of its functions, but anatomical divisions and functional divisions are different. The CNS and the PNS both contribute to the same functions, but those functions can be attributed to different regions of the brain (such as the cerebral cortex or the hypothalamus) or to different ganglia in the periphery. The problem with trying to fit functional differences into anatomical divisions is that sometimes the same structure can be part of several functions. For example, the optic nerve carries signal from the retina that are either used for the conscious perception of visual stimuli, which takes place in the cerebral 28 cortex, or for the reflexive responses of smooth muscle tissue that are processed through the hypothalamus. There are two ways to consider how the nervous system is divided functionally. First, the basic functions of the nervous system are sensation, integration, and response. Secondly, control of the body can be somatic or autonomic—divisions that are largely defined by the structures that are involved in the response. Basic Functions The nervous system is involved in receiving information about the environment around us (sensation) and generating responses to that information (motor responses). The nervous system can be divided into regions that are responsible for sensation (sensory functions) and for the response (motor functions). But there is a third function that needs to be included. Sensory input needs to be integrated with other sensations, as well as with memories, emotional state, or learning (cognition). Some regions of the nervous system are termed integration or association areas. The process of integration combines sensory perceptions and higher cognitive functions such as memories, learning, and emotion to produce a response. Sensation. The first major function of the nervous system is sensation—receiving information about the environment to gain input about what is happening outside the body (or, sometimes, within the body). The sensory functions of the nervous system register the presence of a change from homeostasis or a particular event in the environment, known as a stimulus. The senses we think of most are the “big five”: taste, smell, touch, sight, and hearing. The stimuli for taste and smell are both chemical substances (molecules, compounds, ions, etc.), touch is physical or mechanical stimuli that interact with the skin, sight is light stimuli, and hearing is the perception of sound, which is a physical stimulus similar to some aspects of touch. There are actually more senses than just those, but that list represents the major senses. Those five are all senses that receive stimuli from the outside world, and of which there is conscious perception. Additional sensory stimuli might be from the internal environment (inside the body), such as the stretch of an organ wall or the concentration of certain ions in the blood. Response. The nervous system produces a response on the basis of the stimuli perceived by sensory structures. An obvious response would be the movement of muscles, such as withdrawing a hand from a hot stove, but there are broader uses of the term. The nervous system can cause the contraction of all three types of muscle tissue. For example, skeletal muscle contracts to move the skeleton, cardiac muscle is influenced as heart rate increases during 29 exercise, and smooth muscle contracts as the digestive system moves food along the digestive tract. Responses also include the neural control of glands in the body as well, such as the production and secretion of sweat by the eccrine and merocrine sweat glands found in the skin to lower body temperature. Responses can be divided into those that are voluntary or conscious (contraction of skeletal muscle) and those that are involuntary (contraction of smooth muscles, regulation of cardiac muscle, activation of glands). Voluntary responses are governed by the somatic nervous system and involuntary responses are governed by the autonomic nervous system, which are discussed in the next section. Integration. Stimuli that are received by sensory structures are communicated to the nervous system where that information is processed. This is called integration. Stimuli are compared with, or integrated with, other stimuli, memories of previous stimuli, or the state of a person at a particular time. This leads to the specific response that will be generated. Seeing a baseball pitched to a batter will not automatically cause the batter to swing. The trajectory of the ball and its speed will need to be considered. Maybe the count is three balls and one strike, and the batter wants to let this pitch go by in the hope of getting a walk to first base. Or maybe the batter’s team is so far ahead, it would be fun to just swing away. Lesson 3. Divisions of the Nervous System The nervous system can be divided into two parts mostly on the basis of a functional difference in responses. The somatic nervous system (SNS) is responsible for conscious perception and voluntary motor responses. Voluntary motor response means the contraction of skeletal muscle, but those contractions are not always voluntary in the sense that you have to want to perform them. Some somatic motor responses are reflexes, and often happen without a conscious decision to perform them. If your friend jumps out from behind a corner and yells “Boo!” you will be startled and you might scream or leap back. You didn’t decide to do that, and you may not have wanted to give your friend a reason to laugh at your expense, but it is a reflex involving skeletal muscle contractions. Other motor responses become automatic (in other words, unconscious) as a person learns motor skills (referred to as “habit learning” or “procedural memory”). The autonomic nervous system (ANS) is responsible for involuntary control of the body, usually for the sake of homeostasis (regulation of the internal environment). Sensory input for autonomic functions can be from sensory structures tuned to external or internal environmental stimuli. The motor output extends to smooth and cardiac muscle as well as glandular tissue. The 30 role of the autonomic system is to regulate the organ systems of the body, which usually means to control homeostasis. Sweat glands, for example, are controlled by the autonomic system. When you are hot, sweating helps cool your body down. That is a homeostatic mechanism. But when you are nervous, you might start sweating also. That is not homeostatic, it is the physiological response to an emotional state. Lesson 4. Basic Cells of the Nervous System The nervous system is composed of two basic cell types: glial cells (also known as glia) and neurons. Glial cells, which outnumber neurons ten to one, are traditionally thought to play a supportive role to neurons, both physically and metabolically. Glial cells provide scaffolding on which the nervous system is built, help neurons line up closely with each other to allow neuronal communication, provide insulation to neurons, transport nutrients and waste products, and mediate immune responses. Neurons, on the other hand, serve as interconnected information processors that are essential for all of the tasks of the nervous system. This section briefly describes the structure and function of neurons. Neurons are the central building blocks of the nervous system, 100 billion strong at birth. Like all cells, neurons consist of several different parts, each serving a specialized function. A neuron’s outer surface is made up of a semipermeable membrane. This membrane allows smaller molecules and molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules. The nucleus of the neuron is located in the soma, or cell body. The soma has branching extensions known as dendrites. The neuron is a small information processor, and dendrites serve as input sites where signals are received from other neurons. These signals are transmitted electrically across the soma and down a major extension from the soma known as the axon, which ends at multiple terminal buttons. The terminal buttons contain synaptic vesicles that house neurotransmitters, the chemical messengers of the nervous system. Axons range in length from a fraction of an inch to several feet. In some axons, glial cells form a fatty substance known as the myelin sheath, which coats the axon and acts as an insulator, increasing the speed at which the signal travels. The myelin sheath is crucial for the normal operation of the neurons within the nervous system: the loss of the insulation it provides can be detrimental to normal function. To understand how this works, let’s consider an example. Multiple 31 sclerosis (MS), an autoimmune disorder, involves a large-scale loss of the myelin sheath on axons throughout the nervous system. The resulting interference in the electrical signal prevents the quick transmittal of information by neurons and can lead to a number of symptoms, such as dizziness, fatigue, loss of motor control, and sexual dysfunction. While some treatments may help to modify the course of the disease and manage certain symptoms, there is currently no known cure for multiple sclerosis. In healthy individuals, the neuronal signal moves rapidly down the axon to the terminal buttons, where synaptic vesicles release neurotransmitters into the synapse. The synapse is a very small space between two neurons and is an important site where communication between neurons occurs. Once neurotransmitters are released into the synapse, they travel across the small space and bind with corresponding receptors on the dendrite of an adjacent neuron. Receptors, proteins on the cell surface where neurotransmitters attach, vary in shape, with different shapes “matching” different neurotransmitters. How does a neurotransmitter “know” which receptor to bind to? The neurotransmitter and the receptor have what is referred to as a lock-and-key relationship—specific neurotransmitters fit specific receptors similar to how a key fits a lock. The neurotransmitter binds to any receptor that it fits. Lesson 5. The Central Nervous System The Central Nervous System is comprised of the brain and spinal cord. Brain The brain consists of two hemispheres, each controlling the opposite side of the body. Each hemisphere can be subdivided into different lobes/regions: Frontal - part of the cerebral cortex involved in reasoning, motor control, emotion, and language; contains motor cortex. Parietal - part of the cerebral cortex involved in processing various sensory and perceptual information; contains the primary somatosensory cortex. Temporal - part of cerebral cortex associated with hearing, memory, emotion, and some aspects of language; contains primary auditory cortex. Occipital - part of the cerebral cortex associated with visual processing; contains the primary visual cortex. 32  Figure 3. 1 Brain Functions Source: https://www.healthpages.org/wp-content/uploads/2010/06/brain-functions.jpg In addition to the lobes of the cerebral cortex: the forebrain includes the thalamus (sensory relay) and limbic system (emotion and memory circuit). The midbrain contains the reticular formation, which is important for sleep and arousal, as well as the substantia nigra and ventral tegmental area. These structures are important for movement, reward, and addictive processes. The hindbrain contains the structures of the brainstem (medulla, pons, and midbrain), which control automatic functions like breathing and blood pressure. The hindbrain also contains the cerebellum, which helps coordinate movement and certain types of memories. Spinal Cord In cross section, it is apparent that the spinal cord comprises two different areas: an inner H-shaped core of gray matter and a surrounding area of white matter. Gray matter is composed largely of cell bodies and unmyelinated interneurons, whereas white matter is composed largely of myelinated axons. (It is the myelin that gives the white matter its glossy white sheen.) The two dorsal arms of the spinal gray matter are called the dorsal horns, and the two ventral arms are called the ventral horns. Pairs of spinal nerves are attached to the spinal cord—one on the left and one on the right—at 31 different levels of the spine. Each of these 62 spinal nerves divides as it nears the cord, and its axons are joined to the cord via one of two roots: the dorsal root or the ventral root. All dorsal root axons, whether somatic or autonomic, are sensory (afferent) unipolar neurons with their cell bodies grouped together just outside the cord to form the dorsal root 33 ganglia. Many of their synaptic terminals are in the dorsal horns of the spinal gray matter. In contrast, the neurons of the ventral root are motor (efferent) multipolar neurons with their cell bodies in the ventral horns. Those that are part of the somatic nervous system project to skeletal muscles; those that are part of the autonomic nervous system project to ganglia, where they synapse on neurons that in turn project to internal organs (heart, stomach, liver, etc.). Lesson 6. The Peripheral Nervous System Figure 3. 2 Nervous System Source: https://s3-us-west-2.amazonaws.com/courses-images/wp- content/uploads/sites/2293/2017/08/01155609/CNX_Psych_03_03_Autonomic.jpg The peripheral nervous system is made up of thick bundles of axons, called nerves, carrying messages back and forth between the CNS and the muscles, organs, and senses in the periphery of the body (i.e., everything outside the CNS). The PNS has two major subdivisions: the somatic nervous system and the autonomic nervous system. The somatic nervous system is associated with activities traditionally thought of as conscious or voluntary. It is involved in the relay of sensory and motor information to and from the CNS; therefore, it consists of motor neurons and sensory neurons. Motor neurons, carrying instructions from the CNS to the muscles, are efferent fibers (efferent means “moving away from”). Sensory neurons, carrying sensory information to the CNS, are afferent fibers (afferent means “moving toward”). Each nerve is basically a two-way superhighway, containing thousands of axons, both efferent and afferent. 34  The autonomic nervous system controls our internal organs and glands and is generally considered to be outside the realm of voluntary control. It can be further subdivided into the sympathetic and parasympathetic divisions. The sympathetic nervous system is involved in preparing the body for stress-related activities; the parasympathetic nervous system is associated with returning the body to routine, day-to-day operations. The two systems have complementary functions, operating in tandem to maintain the body’s homeostasis. Homeostasis is a state of equilibrium, in which biological conditions (such as body temperature) are maintained at optimal levels. 35  References Pinel, J.P.J., & Barnes, S.J. (2018). Biopsychology 10th Ed. Pearson Education Ltd. OSCRiceUniversity. (n.d.). Anatomy & Physiology. Creative Commons Attribution 4.0 Spielman, R., Jenkins, W., & Lovett, M. (2021). Psychology. BCcampus. https://opentextbc.ca/h5ppsychology/ Carlson, N. R. (2005). Foundations of Physiological Psychology. Pearson Education Ltd. Kalat, J. W. (2009). Biological Psychology. Wadsworth, Cengage Learning 36  Assessment Task 3-1 Multiple Choice. Read each question carefully, and then choose the best answer. Write your answer in the space provided before the number. _________1. It is ectodermal tissue on the dorsal side of the embryo. a. Neurons b. Neural plate c. Neuron plate d. Neural pathway _________2. After the neural groove and neural tube is formed, cells begin to proliferate, meaning multiply a. Neural plasticity b. Neural multiplication c. Neural proliferation d. Neural propagation _________3. A fingerlike cytoplasmic extension that extends and retracts. a. Filopedia b. Filipedia c. Filopodia d. Filopidoa _________4. It is considered as the central building blocks of the nervous system. a. Neurons b. Neural plate c. Neuron plate d. Neural _________5. It is responsible for conscious perception and voluntary motor responses. a. Central nervous system b. Autonomic nervous system c. Somatic nervous system 37  d. Peripheral nervous system _________6. It is an autoimmune disorder characterized by dizziness, fatigue, loss of motor control, and sexual dysfunction. a. Phenylketonuria b. Autonomic nervous system disorder c. Multiple sclerosis d. Alzheimer’s disease _________7. This lobe is responsible for the individuals reasoning, motor control, emotion, and language. a. Parietal b. Temporal c. Occipital d. Frontal _________8. This is composed largely of cell bodies and unmyelinated interneurons. a. White matter b. Gray matter c. Black matter d. Green matter _________9. This nervous system is involved in preparing the body for stress-related activities. a. Autonomic nervous system b. Peripheral nervous system c. Sympathetic nervous system d. Parasympathetic nervous system _________10. It is the state of equilibrium, in which biological conditions are maintained at optimal levels. a. Balance b. Homeostasis c. Homogenous d. Equilibrium _________11. It controls our internal organs and glands and is generally considered to be outside the realm of voluntary control. a. Autonomic nervous system b. Peripheral nervous system 38  c. Sympathetic nervous system d. Parasympathetic nervous system _________12. This is made up of thick bundles of axons that carries message back and forth. a. Autonomic nervous system b. Peripheral nervous system c. Sympathetic nervous system d. Parasympathetic nervous system _________13. It serves as the scaffolding of the nervous system. a. Gleal cells b. Glial cells c. Gial cells d. Gliel cells _________14. This part of the cerebral cortex is responsible with visual processing. a. Parietal b. Temporal c. Occipital d. Frontal _________15. The ____ is comprised of the brain and spinal cord. a. Central nervous system b. Peripheral nervous system c. Sympathetic nervous system d. Autonomic nervous system 39