Introduction \ fic study of the nervous syste uo be the brains ultimate challenge. oscvence isthe scie isciplines, The primary discipline being biopsy< elated Biopsychology is a field devoted to our vunderstandi biology of behavior. It is also known as ph '. psychobiology, behavioral biology, or be neuroscience: but preferable term is biopsychology because i a biological approach to the study of psychology rather psychological approach to the study of biology. ysiolgical behavioral it denotes. than a The study of the biology of behavior has a long history, but biopsychology did not develop into a major neuroscientifc discipline until the 20th century. Although itis not possible to specify the exact date of biopsychology’s birth, the publication of The Organization of Behavior in 1949 by D. O. Hebb played a key role in its emergence, Hebb developed the first comprehensive theory of how complex psychological phenomena, such as perceptions, emotions, thoughts, and memories, might be produced by brain activity. Hebb’s theory did much to discredit the view that psychological functioning is 100 complex to have its roots in the physiology and chemistry ofthe brain, Hebb based his theory on experiments involving both humans and laboratory animals, on clinical case studies, and on logical arguments developed from his own insightful observations of daily life. This eclectic approach has become a hallmark of biopsychological inquiry Bio-psychologists draw together knowledge from the other neuroscientifie disciplines and apply it to the sty of behavior. The following are a few of the disciplines of neuroscience that are particularly relevant to biopsychology: Neuroanatomy: The study of the structure ofthe nervous system, Neurochemistry: The study of the chemical bases of neural activity, Neuroendocrinology: The study of interactions between the nervous system and the endocrine system, Neuropathology: The study of nervous system disorders, Neuropharmacology: The study ofthe effects of drugs on neural activity. ‘Neurophysiology: The study ofthe functions and activities of the nervous systein, Divisions of Biopsychology: Bio Physiological Paychology Paychopharmacology Neuropsychology yychology bas six major divisions Ow a ee r BASIS OF BEHAY BIOLOGICAL ion, * me ee a 5 «Psychophysiology ; + Cognitive Neuroscience “ mmay prove, Comparative Psychology ¢ ‘Neuroscience comprises several on een 5 Sriicherines Senn tm peel ef ing of th fojlow more than one approach nt . Physiological Psychology: It is the division of bi rie ihe neural mechanisms of behavior troop rranipultion of the brain in controlled experimen, yt Tlestrcal methods of brain manipulation. The get physical pysolgy research are almost ahas igs! tials, because the focus on direct brain manipulation an experiments precludes the use of human subjects in mos Teresa atraton of pure research in physiologic pps theemphasisis usually on research that contributes tothe dev of theories ofthe neural control of behavior rather tan 0 ray that is of immediate practical benefit. 2. Psychopharmacology: Psychopharmacology is simile » Bhysiologial psychology, except that it focuses on the manips ‘of neural activity and behavior with drugs, Infact, many of hea Psychopharmacologists were simply physiological psycholoyss we moved into drug research, and many of today’s biopsychiig identify closely with both approaches. However, the study oft effees of drugs on the brain and behavior has become so speci ‘hat psychopharmacology is regarded as a separate disciple | re Portion of psychopharmacological research is appl se drugs are sometimes used by psychopharmacologss® ® the basic principles of brain behavior interaction, the pups “ological experiments is to develop thersp drug abuse. Psychopharmacologists stu & Poratory species and on humans, ifthe es! it we rugs of to reduce fet of drugs on a the situation permits EY: Neuropsychology is the study of ® mo rain damage in human patients, Obs dane, tically be exposed to expert deals aig mal ‘brain function, Consequt® i Pate ya wih case sais a rain resulting neurone, Te oa ns Comtex is most likely to be ogas AMITPAND AR you! Paychophyss isthe Ee clation between phy sok robe ae in human subjects, Recause the subjects chotowtesjapical research are human, —psychophy siolopical ches ores are typically noninvasive; that is, the eat iy is recorded from the surface of the body. The ea ef brain activity is the scalp electroencephalogram Jommon psychophysiological measures are muscle ‘ome qvement, and several indicators of autonomic nervous ene ty (eat heart rate, blood pressure, pupil dilation, and aductance of the skin), The autonomic nervous system pe division of the nervous system that regulates the body's Hare jent, Most psychophysiological research focuses on evn the physiology of psychological processes, such as Yemotion. and information processing, but there have also ‘of interesting clinical applications of the ‘iological method, For example, psychophysiological have indicated that schizophrenics have difficulty ‘racking e moving object such as a pendulum (e.g,, Chen et pnysiolog Neuroscience: Cognitive neuroscience is the youngest ‘of biopsychology. but it is currently among the most active ing. Cognitive neuroscientists study the neural bases of ‘term that generally refers to higher intellectual processes ‘ss thought, memory, attention, and complex. perceptual Because of its focus on cognition, most cognitive research involves human subjects; and because of its human subjects, its methods tend to be noninvasive, rather iving penetration or direct manipulation of the brain. The ‘method of cognitive neuroscience is functional brain imaging jing images of the activity of the living human brain) while a is engaged in a particular cognitive activity. ative Psychology: Comparative psychology is the division logy that deals generally with the biology of behavior, than specifically with the neural mechanisms of behavior. ive psychologists compare the behavior of different species to understand the evolution, genetics, and adaptiveness of . Some comparative psychologists study behavior in the ; others engage in ethological research ie. the study of ‘ior in its natural environment. The two important areas ical research that also employ comparative analysis ‘considered as part of comparative psychology. One of these Psychology (a subfield that focuses on understanding by considering its likely evolutionary origins. The other is enetics (the study of genetic influences on behavior. UNIT BIOLOGICAL BASIS OF BEHAVIOR CENTRAL AND PERIPHERAL NERVOUS SYSTEMS The nervous system controls bodily function by gathering sensory input, integrating that information internally, and communicating Proper motor output The nervous system can be divided into two major regions: the central and peripheral nervous systems. The central nervous system (CNS) ! the brain and spinal cord, and the peripheral nervous system (PNS) 's everything else. The brain is contained within the cranial cavity of the skull, and the spinal cord is contained within the vertebral cavity of the vertebral column, It is a bit of an oversimplification to say that the CNS is what is inside these two cavities and the peripheral nervous system is outside of them, but that is one way to start to think about it In actuality, there are some elements of the peripheral nervous system that are within the cranial or vertebral cavities. The peripheral nervous system is so named because it is on the periphery ing beyond the brain and spinal cord. Depending on different aspects of the nervous system, the dividing line between central and peripheral is not necessarily universal + The nervous system is the body’s main communication system; it gathers, synthesizes, and uses data from the environment, ~ The most basic unit of the nervous system is the neuron, which serves as both a sensor and communicator of internal and external stimuli - The nervous system can be broken down into two major parts— the central nervous system and the peripheral nervous system. = The central nervous system, the main data center of the body, includes the brain and spinal cord. ~The peripheral nervous system includes all the neurons that sense ‘and communicate data to the central nervous system. ~ The peripheral nervous system can be further divided into the autonomic system, which regulates involuntary actions, and the somatic system, which controls voluntary actions. The key aspects to study in the Nervous system include: 1, Central Nervous System - Brain = Spinal Cord 2, Peripheral Nervous System - Somatic Nervous System - Autonomic Nervous System ‘© Sympathetic Nervous System © Parasympathetic Nervous System 3, Protection Support Systems - Meninges - Ventricles and Cerebrospinal Fluid - Blood Brain Barrier 121— Anatomical Direct Directional terms are used to - identify one structure in relation 10 another. Some terminologies, such as dorsal 7 or ventral, are relative to the . 7 axis of the central nervous system, therefore the direction these phrases define varies depending on whether they are used for brain areas or other body regions. Other adjectives, such as superior or inferior, retain their meaning throughout the body. Anterior: In front of; toward the face Posterior: Behind: toward the back Superior: Above: toward the head Inferior: Below: toward the feet Medial: Toward the middle Lateral: Toward the edge Dorsal: Toward the top of the brain or the back of the spinal cord Ventral: Toward the bottom of the brain or the front of the spinal cord, Rostral: Toward the front of the brain or the top of the spinal cord Caudal: Toward the back of the brain or the bottom of the spinal o ‘There are planes or axes that can be used to examine the nervous system. The frontal or coronal plane is a vertical plane in a medial to lateral direction, dividing objects into front and __ back pieces. The sagittal plane is also a vertical plane but in a | rostral-caudal rection, meaning it divides objects into right and left regions. Finally, the horizontal plane divides ‘objects into top and bottom regions. Poet Wit HIE CENTRAL NERVOUS SYSTEM (ONS) The central nervous system is made Up of the bra, The brain is the part of the NS located in the skull; the spinal cord is the part located in the spine Together with the peripheral nervous system (PNS), the CNS performs fundamental functions that contribute to an organism's life and behavior. Activity of the CNS The nervous system has three main _ functions: gathering sensory information from external stimuli, synthesizing that information, and responding to those iy da “information synthesizing” function. During this al elie oe, the brain and spinal cord decide on appropriate motor oupu. naa computed based on the type of sensory input. The CNS rep everything from organ function to high-level thought to body movement. Thus, the CNS is commonly thought of asthe eae center of the body. Structure of the Central Nervous System ‘The CNS is comprised of the brain, brain stem, and spinal con. Brain: The human brain is in charge of almost every aspect a human body, from physiological functions to cognitive capacita’ works by receiying and delivering impulses to various pars a body via neurons. The human brain has the same basic most other mammals, although it is more evolved than an mammalian brai The brain is anatomically enclosed within the cranium surrounded by cerebrospinal fluid. An adult brain weighs kg and 1.5 kg on average. It is mostly made up of neurons, the basic building blocks of the brain and nervous system. to recent estimates, the brain has anywhere from 86 billion neurons, ‘The central nervous system is made up of the brain und the ‘The brain is divided into three sections: ‘The telencephaton (the left and right cerebral like in other higher vertebrutes, grows the most during ‘The remaining four divisions of the bruin are the brain stem—the stem on which the cerebral hemspher™ The medulla is another name for the myelenvephaloeANWAR sera tom scones he underside of the bain soc Tain, pos. and medulla, The midhrain is found cf in athe fosbra U eultes mtr function vy sensory information to pass from the brain to sm pe ps houses the ont centr fr respiration tne The medulla also helps regulate respiration, Tar and digestive functioning yor and 5 “et _-pe inal cord isa taiblike structure embedded in the ent fhe spine. The adult spinal cord is about 40 cm long canal imately 30 8. The spinal cord is attached to the vss aa medulla oblongata, and is organized to serve four asks sey usinly sensor) information tothe brain: se fran generated in the brain to priphea az mp sheetal muscles: te 1 organs via the autonomic nervous system: peo ensorimovor functions fo control posture and other » een mere sal cord connects the brain and brain stem to all of the major wai body. Spinal nerves originate fom the spinal cord and fhe fnctions ofthe rest ofthe body. Impulses are sent from ‘hough the spinal cord to the brain, where they are ‘and symthesized into instructions for the rest of the body. sn shen seatback through the spinal cord to muscles and and Function of the Brain juman brain is one ofthe most complex systems on earth. Every cof the brain must work together in order to keep its body ing. The brain andthe spinal cord make up the central nervous inhsh alongside the peripheral nervous system is responsible all bodily functions. seehs to explain the mental processes and behavior of ty studying the interaction between mental processes and on a systemic level. Therefore, the field of psychology is intertwined withthe study of the brain. Structure of the Brain 1 in other higher vertebrates, the telencephalon (the left cerebral hemispheres) undergoes the greatest growth during our divisions ofthe brain are often referred to collectively stem—the stem on which the cerebral hemispheres sit. isoften refered toas the medulla. The five major ofthe brain are- Forebrain (divided into Telencephalon & Midbrain (Mesencephalon), and Hindbrain & Myelencephalon). Hindbrain ‘nbencephalon (or Hindbrain) is divided into two parts: and myelencephalon. The metencephalon develops OR UNIT. RIOLOGIEAL BASIS OF BEHAV ain’s cerebellum i the alt ; the and pons myelencephalon the adult brain's medulla, which whereas develops inte contains a large fourth ventricle or choroid plexus i 1 F_and posterior the thin roof. The hindbrain eves as a channel for information to travel between the forebrain and the spinal cord The Hindbrain is sub-divided into- Myelencephalon (medulla), and Metencephalon. Myelencephalon tt gets its name from its net-like b look (reticulum means “little Figure: i Siractres ofthe human net” in Latin). Because sections ‘myelencephalon medulla) and of the reticular _ formation appear to have a role in arousal it is sometimes referred 10 as the reticular activating system, ‘The numerous nuclei of the reticular formation, on the other hand, are involved in a range of tasks, including sleep. attention, movement. muscle tone maintenance, and various cardiac, circulatory, and respiratory responses. As a result, referring to this collection of nuclei as a system can be deceptive, Reticular Formation: Its an interesting part of the myelencephalon from a psychological perspective. It is a complex network of about 100 tiny nuclei that occupies the central core of the brain stem from the posterior boundary of the myelencephalon to the anterior boundary of the midbrain, It is so named because of its netlike appearance (reticulum means “ttle net”). Sometimes, the reticular formation is referred to as the reticular activating system because parts of it seem to play a role in arousal However, the various nuclei of the reticular formation are involved in 2 variety of functions—including sleep, attention, movement, the maintenance of muscle tone, and various cardiac, circulatory, and respiratory reflexes. ‘Accordingly, referring to this collection of nuclei as ssstem can be ‘misleading. ‘Metencephaton" he reticular foemahen, Posy Pons halon, like the myelencephalon, hawwses many and descending tracts and part of the reticular formation 1 bulge, called the poms, on the brain stem’ foce The pons is one mayor division af the metencephalen (oo 8 Latin, Herally means the bridge The pons connects the ‘1np past of your brain (the cerebrum) to the cerebellum fregulates ‘vement) thus allowing them to function in syme, In combination sth the medull a, the pons ects the eerebri ‘he spinal cord and ensures that nerve impulses can travel freely Uhvowgh your whole bey. MH therefore acts asa bridge in your nervous stem The main functions of the pons include: Controlling sleep cycles. the magnitude and frequency ofthe respiration, Iransfers information between the cerebellum and motor cortex Pons 15 also involved in sensations, such as the sense of taste, hearing and balance, Cerebellum: Its also known as the little brain, The cerebellum is the large, convoluted structure on the bran stem’s dorsal surface. It is an ‘important sensorimotor structure; cerebellar damage eliminates the ability 10 precisely control one's movements and to adapt them to changing conditions. However, the fact that cerebellar damage also produces a variety of cognitive deficits (e.g, deficits in decision ‘making and in the use of language) suggest that the functions of the cerebellum are not restricted to sensorimotor control. The cerebellum consists of two hemispheres, the outer grey cortex and the inner white ‘medulla. [tis mainly responsible for coordinating and maintaining the body balance during walking, running, riding, swimming, and precision control ofthe voluntary movements. The main functions of the cerebellum include: It senses equilibrium. ‘Coordinates eye movement, ‘It enables precision control of the voluntary body movements. * Predicts the future position of the body during a particular Aifteremt nece In addition to the eetier Ronmatign ood “ tment cna the cob uae pts the prc pot Pa the ni ssf — a ec an = ‘The periaqueductal gray isthe gray mater situated sry aqueduct, the duct connecting the third and fourh ca interest because of its role in mediating te alge, reducing) effects of opioid drugs. : ‘The substantia nigra (black substance) and there nce important components of the sensorimotor system, Forebrain ofthe developing brain, including the most complex central nervous ssee ‘The diencephalon and telencephalon are two regio ¢, forebrain, The diencephalon is located at the botom of he contains the thalamus and hypothalamus (which fom te system); the telencephalon is located on top of the di contains the cerebrum, which houses the bri by cognitive processing. The vast and sophisticated forebas#: ‘human brain distinguishes it from other vertebrate brainsEI AMT PANWAR ils yc" sn stem. The third ventricle has one lobe on each side, ws lth obs te venice re linked by the Massa intermedia, whieh rune White lamina(layers) of myelinated axons can pe surface ote tales ont lamas is made up of many different pairs of nuclei, iy projet 0 the cortex. The sensory relay nucles studied thalamiv nuclei—nuclei that receive signals Mt cepnors process them, and then transport them to the ns of sensory cortex. The lateral geniculate nuclei, elate auc and Ventral posterior nucle, for example, are ty stations in the visual, auditory, and somatosensory in ctively. Therefore, the thalamus is responsible for mus: The hypothalamus is positioned directly beneath the alas (hypo means "below" in Greek). Itis considered the fegion ofthe brain, 2s it's involved inthe following functions peceives impulses Regulates body temperature onls the mood and emotions Cons the sense of taste and smell synthesizes the body's essential hormones Coordinates the messages from the autonomous nervous system CConzls appetite, peristalsis, the rate of heartbeat, and blood Forms an axis with the pituitary gland which is the main link fetween the nervous and the endocrine systems the human brain's biggest division, mediates the ‘MOM sophisticated activities, It is responsible for initiating UNIT: BIOLOGICAL BASIS OF BEHAVIO Voluntary movement, interpreting sensory input, and mediating Complex copnitive processes peaking, and Problem solving CEREBRAL CORTEX: rs the cerebral aril ie 1s prim: The cerebral cortex is a layer of ti hemispheres (cerebral bark). Because the cerebral made up of tiny, unmyelinated neurons, itis grey and & referred to as grey matter. The layer beneath the cortex hand, is mostly made up of massive myelinated axons that ae and are commonly referred to as white matter ii ov other white is extremely convoluted (furrowed) without The cerebral cortex in hun Convolutions increase the amount of cerebral cortex increasing the overall volume of the brain, Not all animals have convoluted cortexes; the majority of mammals have lissencephalic cortexes (smooth-brained).. Tt was originally thought that the number and size of cortical convolutions determined a species’ intellectual abilities: however, the ‘number and size of cortical convolutions appear to be more related to body size, The cortex of any large mammal is very convoluted. The broad furrows in a convoluted cortex are known as fissures, while the little ones are known as sulci (singular sulcus). Gyri are the ridges that run between fissures and sulci (singular gyrus). The greatest of the fissures, the longitudinal fissure, appears to split the brain hemispheres almost completely A few tracts across the longitudinal fissure connect the cerebral hemispheres; these hemisphere-connecting tracts are known as cerebral commissures. The corpus callosum is the greatest cerebral ‘commissure. The central fissure and the lateral fissure are the two key features on the lateral surface of each hemisphere. Each hemisphere is divided into four lobes by these fissures: the frontal lobe, the parietal lobe (pronounced "pa-RYE-e-tal"), the temporal lobe, and the cccipital lobe (pronounced "ok- SIP-i-tal”). The precentral postcentral gyri, and superior temporal gyri are the biggest gyri in the frontal, parietal, and temporal lobes, respectively ri, Itis ctitical to recognise that the cerebral lobes are not functioning ‘units. The cerebral cortex is best thought of as a flat sheet of cells that happens to be separated into lobes because it folds in on itself at particular points during development. As a result, it is inaccurate to believe that a lobe is a functional unit witha single set of functions The occipital lobes’ primary function is straightforward: We humans rely substantially on visual input analysis to guide our behaviour. an the occipital cortex and large portions of surrounding cortex serve this purpose, Each parietal lobe has two large functional areas: The postcentral gyrus analyses bodily sensations (¢.g., touch), whereas the remaining sections of cortex in the parietal lobes perform roles in nsing the location of both things and our own bodies. as well asin directing our attention. Each temporal lobe's cortex has three general functional areas: The superior temporal gyrus is engaged in hearing and language, the inferior temporal cortex recognises vomple sual patterns, and the medial emporal cortex (which is not visible from the 15Sede Mew ys involved in some typeset memory Finally Ne ts ante two functional areas The precentral orfey pertonm motor funetions, whereas \ anterior fo the motor cortex performs complex Ve foremons such as planning response sequences, evaluating + of potential pattems of behaviour, and assessing Soo fieanee of other people's behaviour, The neocortes (new cortex), so Knows as Gowurtes, aooounts for approximately 90% of the seman combwal corter The layers of the neocortex are numbered 1 2b V1. beginning at the surface. Figure 3.26 depicts two adjacent rewoter Slices. The first was stained with a Nissl stain to expose the quanoiy and shape of its cell bodies, while the second was treated with 4 Golg) sttin fo reveal the silhouettes of a small proportion of its Vhe Limbic System & The Basal Gan; Other than the ones pmjecting to and from the neocortex in the relencephalon, there are other significant subcortical nuclear groups. ese are either pant of the Li m or the Basal Ganglia Xe is vital to emphasize that when we say “system,” we don't mean a scuctural system coming together to form these, but rather they form # system based on their roles, Therefore, it can be said that the concepts of limbic system and basal ganglia system provide a useful means of conceptualizing the organization of several subcortical srructures, ‘The limbic system is a circuit of midline structures that circle the thalamus (limbic means “ring”). The limbic system is involved in the regulation of motivated behaviors—fleeing, feeding, fighting, and sexual behavier. In addition to the structures about which you have already read (the mammillary bodies and the hippocampus), major structures of the limbic system include the amygdala, the fornix, the cangulate cortex, and the Septum. The Amygdala is an almond-shaped nucleus in the anterior temporal lobe (amygdala means “almond”), Posterior to the amygdala is the hippocampus, which runs beneath the thalamus in the medial temporal foe Next in the ring are the cingulate cortex and the fornix. The cingulate conten is the large strip of cortex in the cingulate gyrus on the medial surface of the cerebral hemispheres, just superior to the corpus callosum, it encircles the dorsal thalamus (cingulate means encircling”) The fornia. the primary limbic tract, also encircles the dorsal thalamus; a leaves the dorsal end of the hippocampus and sweeps forward in an ‘arc quursing over the superior surface of the third ventricle and ermunating in the septum and the mammillary bodies (fornix meaning wars) The septum 1s # midline nucleus found at the cingulate cortex's amserna top. The limbic ring 1s completed by many tracts that connect the septum and mammutiary bodies to the amy gdala and hippocampus. The farctieans of the hippocampus, hypothalamus, and amygdala have revered greater attention than those of other limbic structures. The bippmampus. a2 previously established, is involved in some forms of hale the hypothalamus os engaged in a range of motivated Power Wi sctivitien such an eating, sleeping, ‘and: ene, amygdala, on the other hand, is involved inet! bey fear ‘tin emetin Basal Ganglia: The long tail-like caud, like") and putamen (pronounced "pew-T receive input from the neocortex ate (candy AY men”) of of ae The striatum pM «ale and putamen, both of which exhibits 2% g® pe (striped. structure). The striatum’s primary oy “. pallidus, a pale circular structure (pale globe), 1 positioned between the putamen and the thal putamen. THe Blaha” lamus, mas The basal ganglia are involved in voluntary motoy de making. A passage from the substantia nigra yp 2» to the striatum is of particular interest: Parkinson's 4) marked by rigidity, tremors, and a lack of Polenta - connected with the degeneration of this pathway. 1 accumbens, which is located in the medial repion of striatum, is another component of the basal gan,” biopsychologists are particularly interested in. Its consienan,® nucleus accumbens plays a role in the rewarding effec stax substances and other reinforcers Cerebral Hemispheres and Lobes of the Brain The brain is divided into two hemispheres and four lobes cx: which specializes in a different function, Brain Lateralization The brain is divided into two halves, called hemispheres. Tie evidence that each brain hemisphere has its own distinc funcue phenomenon referred to as lateralization. The left hemisphere a= to dominate the functions of speech, language procesing = comprehension, and logical reasoning, while the right ® » dominant in spatial tasks like vision-independent object resom= (such as identifying an object by touch or another non-visu = However, it is easy to exaggerate the differences betes 4 functions of the left and right hemispheres; both hemispher involved with most processes. Additionally, neuroplastio® ability of a brain to adapt to experience) enables the = ‘compensate for damage to one hemisphere by tahing © functions in the other half, especially in young brains. Corpus Callosum ‘The two hemispheres communicate with one another tt corpus callosum. The corpus callosum is a wide, flat buns fibers beneath the cortex that connects the left and net hemispheres and facilitates interhemispheric commun ‘corpus callosum is sometimes implicated in the cane Patients with epilepsy 2 corpus callestor” removal of the corpus callosum, ‘The Lobes of the Brain ot , three main PA The brain as a whole can be cerebrum, the cerebellum, and thest AMIT PANWAR small part of the brain located at the back just tn eit has two hemispheres like the cerebrum wna} teainste untary muscle movements like posture and the cerebrum with the spinal cord: it is made pons, and medulla, and it plays a large role in both mg avotuary movement isis the main and largest part ofthe brain, itis made of matter and is responsible for movement, temperature ere} Hh. judgment, thinking, hearing, vision, problem. Jruch more. ofthe cerebrum is made up of 4 lobes: temporal, occipital, parietal has four lobes: frontal, parietal, occipital, and temporal, ‘he front portion of the brain extending back to the central jnvolved in language, motor control, and other executive higher thinking, Jocated directly behind the frontal lobe and towards the top itis responsible for processing sensory inform: the very back portion of the brain where vision is processed located on the sides of the brain; associated with OR UNIT 4: BIOLOGICAL BASIS OF BEL AVIOF Frontal Lobes Func Parlier it was said that frontal lobe functions involved motor control Personality, and behavior. Within the frontal lobe are two m functional areas; an area involved with movement and an area involved with behavior. The motor cortex: It is made of the primary motor cortex and motor association cortex which is the backside, or posterior portion. of the frontal cortex. It controls voluntary muscle movements. fine motor Movements, spontaneous motor movements, eye movements, and the ability to plan and carry out a sequence of movements. Damage to the motor areas or the blood supply to motor areas can cause movement disorders, The prefrontal cortex: It is responsible for executive function cognition, motor planning, working memory, attention. personality ‘mood, behavior, reasoning, judgment, and impulse control. It is the most anterior section of the frontal cortex. Damage to the prefrontal cortex can cause short-term memory problems, personality changes. neuropsychiatric symptoms, and behavioral inhibition. The prefrontal cortex is deeply involved with multiple other brain structures within the central portion of the brain that together comprise the limbic system. The limbic system is critical for processing emotions, behavior, and memory. The frontal eye fields: They are right behind the prefrontal cortex and control some types of eye movements. Broca’s area: Pierre Paul Broca, a French neurosurgeon, is credited with discovering this area of the brain. It can be located in either the left or right hemispheres of the frontal cortex, depending on whether a person is right or left-handed. It controls the muscles that make speaking possible, including the tongue, pharynx, and larynx. is essential to language formation and als, It relays information from one area of the brain to another, resulting in coherent communication patterns. When an individual suffers from brain damage, they may understand the language but are unable to speak fluently. ‘New research out of John Hopkins indicates that Broca’s area is responsible for forming sentences by coordinating information between different brain areas. Damage to Broca’s Area: Stroke, epilepsy, and brain damage can all render this specific part of the brain useless. The individual with Broca's aphasia, the speech condition caused by damage to this area of the brain, is also referred to as expressive aphasia. The individual ‘will have difficulty expressing what they are thinking, advocating for themselves, and not meeting their needs by society. This con ‘causes the individual to be ineffective in their communication; this can be particularly frustrating because they can understand what is bei fand formulate what they want to say, However, they can not get ‘words out in an orderly fashion, TEMPORAL LOBE sp 127‘an be fount on the sides of the head by the ents vy casTs hemisphere of the brain he temrara lobe the yetention of short- and fongstenm memes. Ih wl inlining auditory: information, fangmage von, and namin Wall ereates emotional responses and val drives such as aggression and sextaity wnporal Lobe contains the hippocampus, whieh is the memory ‘the brain. The hippocampus plays a key role in the formation ‘memories hased on emotional input from * amypdala. The left temporal lobe holds the primary auditory "We, which is important for processing the semantics of speech. Jaden, long. "portant Structures in the Temporal Lobe: Fach temporal lobe ‘contains nvultipte subsstruetures whic I roles. sins multiple substructures which play important rol Si lt ‘most people, Wemicke’s area is the lel cerebral hemisphere, specifically near the tobe. This portion ofthe bein is very important for being a Process and understand the words of others, This area is believed 10 be ‘unique to the fu Comprehension, specifically the comprehen 's also considered to be the receptive languay Individuals who have damage to Werniche condition known as Wernicke's ap ‘aphasia generally have difficulties, Damage to Temporal les: When there Jobe, one’s memory, speech, language cater function ofthe temporal lobes may damage depends on where precisely the the right or left lobe, ‘THE OCCIPITAL LOBE,IEE Can AM PANWAR ious! , avon 16 the parietal le, whichis responsible far oes and location. This stream is responsible is for odies are responsible for recei snieulte ceiving visual wr lyf the retinas within each eye andi then sends in inthe visual cortices within the ociptl lobes, These 4 within the thalamus, which is an important relay eer isan area within the ocipital lobe that primarily receives formation describing the field of vision. It has also been important in encoding visual memories, processing eters Se ‘and determining temporal order. to the occipital Lobe she expt lobe experiences trauma and is damaged, the first is offen ‘seeing stars. This is because when pressure is rots art, the neurons may fire without control, resulting in vidual suddenly perceiving visual starlike spots that are not present, Severe damage tthe occipital lobe most often results However, there are many other consequences, including: Movement difficulties: damage to areas corresponding to depth eretion may lead 10 difficulties in movement contol and navigation. Recognition difiulties: damage to areas pertaining to facial or thjet recognition may affect the ability to recognize them. Prosopagnosia is a disorder defined by having difficulties recognizing faces, resulting from damage in the temporal lobe ‘nds connections to certain areas within the visual cortex. Epilepsy: Seizures may result asa consequence of damage inthis, wea. Difficulties with color perception: This includes difficulties perceiving shapes, sizes, and dimensions. PARIETAL LOBE areal lobe is located directly behind the frontal lobe and above lobes. The frontal and parietal lobes are separated by the sulcus, which is the groove between these two lobes. iy, the parietal lobe is located above the parietal bone, ‘isthe large bone that forms the top, rear portion of the skull Jobe occupies roughly one-fourth of the total area of each ofthe brain, lobe isthe primary sensory area of the brain, which means ‘he portion of the brain responsible for processing sensory ' The primary somatosensory area of the parietal lobe 10 process this sensory information, The sensory information by the parietal lobe is known as somatic senses, which refer Netses detected atthe surface of the skin. These senses include: UNIT, BIOLOGICAL BASIS OF BETASIO® Temperature Touch Pain Pressure AAs a parietal lobe function example, pretend you touch somethin hot with your index finger. Neurons in your index finger will wend a Clectrica impulse ta the parietal lobe, The parietal lobe will prow this impulse, and you will feel the “hot” sensation in your finger Th entire process occurs almost instantaneously, and this same seqven of events occur forthe sensations of touch. pain, and pressure ‘Sensory information from the head is processed by the bottom portions of the postcentral gyrus, while sensory information from the lower Portions ofthe body is processed bythe tp portions ofthe posteentral gyrus, In addition to sensory processing, functions of the parietal lobe also include: ~ Knowing the location of various parts of your body without looking at them (known as visuospatial processing) Determining the size and shape of an object ~ Judging distances (such as the distance between to different objects) ~ Understanding spatial orientation (such as where your hand is Jocated in relation tothe rest of your body) ~ Interpretation of symbols (such as codes and puzzles) ~ Processing formation Anatomy of the Parieta! Lobe: There are several important parts of the parietal lobe anatomy, which include: Postcentral gyrus: A prominent ridge that extends into the lateral Portions of both the right and left sides of the parietal lobe. Primary somatosensory area: This arca ofthe parietal lobe receives and processes sensory information from throughout the body, and itis located in the posteentral gyrus Baum's loop: Baum’s loop (also known as optic radiation) consists of neurons, and it forms the visual pathway. Baum's loop travels through the parietal lobe as it extends from the thalamus to the occipital lobe The occipital lobe isthe primary location of the brain responsible for processing visual information. Right Parietal Lobe: The parietal lobe of the right side of the brain will process sensory information from the left side of the body. For ‘example, if you touch something cold with your left foot, the parietal lobe on the right side of your brain will process this sensory information. The right parietal lobe also seems to be more involved in understanding images, spatial awareness, movement of the boul. and visualization. Left Parietal Lobe: The parietal lobe of the left side of the brain wll process sensory information from the right side of the body For ‘example, if you are pinched on your right arm, your left parietal lobe will process this sensory information. The left parietal lobe also seems 129J inv anderstanding symbols, language, math, and persars donusant hand will determine whieh pa Factive A person vehe is left-handed will have a more parcial Jobe an ther brain's ght hemisphere, A person whe is uted voll have # more active parietal tobe on their brain's left al Lobe Damage that can be caused by These following sections to the par ibe some of these conditions, Optic Ataxia: 11 is often results from damage to both sides of the This condition results in the inability of @ pervon to v curately move their hand due to impaired guidance from their eyes For example, a person with optic atuxia will have difficulty reaching out and grabbing an object, because their parietal lobe will have Uifficulty processing visual information to help guide their hand to the object parietal to tic Apraxia: [tis also known ax ocular apraxia) often results from ve to both sides of the parietal lobe. This condition results in the inability of @ person to control the movements of their eyes, People with this condition often move their heads to change their eyesight instead of moving their eyeballs. Sensory Inattention: It is caused by a lesion on the parietal lobe, and ‘affects bilateral stimuli, For € ample, if you touch both hands of a perion with sensory inattention, shey will only be able to feel you ‘ouching one of their hands. If the person has a lesion on their right parietal lobe, they will not be able to feel sensations on their left hand. 1 the person hay a lesion on their left parietal lobe, they will not be able to feel sensations on their right hand, Gerstmann's Syndrome: It is caused by damage to the left parictal lobe, Common problems associated with this condition include: Difficulty in differentiating right and left Agraphia: inability to write Acalculia: difficulty in understanding math Finger agnosia: inability 10 recognize your finger or another person's finger LUE SPINAL CORD Along with the brain, the spinal cord completes the Central Nervous System. The Spinal Cord is one out of the two divisions of the CNS. It 1s a pipe-like structure that is usually 40-42 em long and 2 em wide In adults, the spinal cord ends at the upper part of the curvature of the lower back and extends upward to the base of the skull where it joins the brain. The spinal cord is protected by membranes called meninges [collectively made up of the dura, arachnoid, and pia mater) and the “pinal column of bony vertebrae, Sensory fibers enter dorsally, and inotor fibers exit ventrally. uk between the brain fy forums a vital bank b 5 different sections d comprises two different areas, al cond comp " ate rong FT ite mat kg Gray matter 16 composed I The spin ty of cell bodies ang whereas white matter is com sed targets inte large rene, Ht is the myetin that insulates the axons ghee 2m its glossy white sheen ive i ai cv ‘Thoracic Tle TO T-t1z Lumbar ULV Li-ts Sacrum s1 SI-ss ‘The two dorsal arms of the spinal gray matter are called the doy hors, and the two ventral arms are called the ventral hors, Pins spinal nerves are attached to the spinal cord— one on the left andy, ‘on the right—at 31 different levels of the spine. Each of these 62 pi nerves divides as it nears the cord, and its axons are joined tothe cr via one of two roots: the dorsal root or the Ventral root. (Gray matter Dorsal root Spinal nerve All dorsal root axons, whether pe netintiredoerie somatic or autonomic, are rons with their cell bodies 4 contrast, the "ultpolar neury Reurons of the ventral root are ns with their cell bodies in the ventralane erate NerWOU SEM EJECT Ho Sheet pate of he alms MerVOUN system projet oem are pa ons that in twin project to pcan pit into thre different areas fit ee caton Nighy that sends instructions om he ons ofthe body, including taining muscles that % sensory formation tothe brain, When you touch Fe enarmple,neves translate the Sensation and send i processing plant, the brain, years xive or automatic actions tke heartbeat or wt yes 10-an extemal stimulation lke a bright light fa simple and uncontrolled response oF a learned iis also involved in things like body temperature a Arc in the Spinal Cord Note: Ganglia is the plural of the word ganglion, Ganglia of nerve cell bodies found throughout the bod). They ofthe PNS and carry nerve signals to and from the CNS, — OS OF ALHAVIOR® UNE IIOLOGIOAL BASIS OF BEE THEPERIPILERAL NERVOUS SYSTEM (ENS) he peripheral nervous system connects the central nervow ewironmnenta tin The peripheral nervous system (PNS) is cine of the wo Ma omponents of the bay's nervous system, In conjunction wih Ihe Sena nervous system (CNS), the PNS coordinates action and Fesponses hy sending signals from one part of the boxly to another The ONS includes the brain, brain stem, and spinal cord, while the P'S includes all others nd co ory neurons, clusters of neurons called ganglia lector neurons that attach to the CNS and other neurons * The peripheral nervous system (PNS) provides the connection between internal or extemal stimuli and the central nervous System to allow the body to respond to its environment The PNS is made up of different kinds of neurons, or nerve cells, which communicate with each other through electric signaling and neurotransmitters The PNS can be broken down into {wo systems: the autonomic nervous system, which regulates involuntary actions such as breathing and digestion, and the somatic nervous system, which {gover voluntary action and body reflexes. ‘The autonomic nervous system has two complementar sympathetic nervous system, which activates the “fight-or-flig orfreeze” stress response, and the parasympathetic nervous system, which reacts with the “rest-and-digest” response after stress * The somatic nervous system coordinates voluntary physical action. It is also responsible for ourreflexes, which do not require brain input ms of the Peripheral Nervous System ‘The peripheral nervous system is also composed of two divisions: the ‘somatic nervous system and the autonomic nervous system, ‘Somatic Nervous System: The somatic nervous system (SNS) is the Part of the PNS that interacts with the external environment. It is, ‘composed of afferent nerves that carry sensory signals from the skin, skeletal muscles, joins, eyes, ears, and so on, o the central nervous system and efferent nerves that carry motor signals from the central nervous system to the skeletal muscles. ‘The somatic nervous system keeps the body adept and coordinated, both through reflexes and voluntary action, The somatic nervous system controls systems in areas as diverse as the skin, bones, joints, and skeletal muscles. Afferent fibers. or nerves. that receive {information from extemal stimuli, carry sensory information through pathways that connect the skin and skeletal muscles to the CNS. for [rocessing. The information is then sent back via efferent nerves, or nerves that cary instructions from the CNS, back throueh the somatic system, These instructions yo to neuromuscular junctions —the Jerfaces between neurons and muscles—for motor output 10 provides us with reileves, Which are futomatic and do not require input or integration thom the brain to perform. Reflexes can be categorized ay either monossnaptic or 131powerwithinpsych polysynaptic based on the reflex arc used to perform the function. Monosynaptic reflex arcs, such as the knee-jerk reflex, have only @ single synapse between the sensory neuron that receives the information and the motor neuron that responds. Polysynaptic reflex arcs, contrast. have at least one interneuron between the sensory neuron and the motor neuron. An example of a polysynaptic reflex arc is Seen when a person steps on a tack—in response, their body must pull that foot up while simultaneously transferring balance to the other leg. Afferent: A = Arrive towards CNS or Admit into CNS Efferent: E = Exit or Escape away from CNS ‘The autonomic nervous system (ANS): Itis the part of the peripheral nervous system that regulates the body's intemal environment. It is composed of afferent nerves that carry sensory signals from internal organs to the CNS and efferent nerves that carry motor signals from_ the CNS to internal organs. . ‘The autonomic nervous system has two kinds of efferent sympathetic nerves and parasympathetic nerves. The nerves are autonomic motor nerves that project from the Ch lumbar (small of the back) and thoracic (chest area) spinal cord. The parasympathetic nerves are those autor nerves that project from the brain and sacral (lower back) spinal cord. The autonomic nervous system controls specific body p as circulation of blood, digestion, reathing, urinatio The autonomic nervous system is named so, autonomously, i.e., without a person's conscious known as Involuntary Nervous System. ‘The primary function of the autonomic nervous sy Apart from maintaining the body’s internal involved in controlling and maintaining the Digestion Metabolism Urination Defecation Blood pressure Sexual response Body temperature Heartbeat Breathing rate Fluid balance There are two main flavors of sensory somatic and visceral. Somatic sensory of the eyes, ears, nose, tongue, and information we associate with the five comes from the viscera, or internal organs, tabs on the heart, lungs, stomach, and manage their regulation ‘The Sympathetic and Par There are two main divisions of the part of the nervous system that is, to stimuli, The sympathetic intense physical activity and isAMI PANWAR ors sions men-IN-gees”) ' cond (the CNS) are the most protected organs in oot covered with the Skull and the Spinal Cord ah Te vertebral Column. To add further protection, there ial protective meMBANEIBVErS PEM hetween the ee Ba nx (singular of meninges) is @ tough membrane called tough mother). Immediately inside the dura mater ig let sh fd membrane (spider-websIike membrane), Berea Mrnbrane isa space called the subarachnoid space an lage blood vessels and cerebrospinal uid ae woes mis the dla pia mater pus meter Mf the CNS, F este sie two layers: Outer Periosteal Layer/ Endosteal and Inner Layer. The fluid separating the It connects meninges to the Skull and Cavity into different compartments extending support to the sub-division ofthe brain. ‘Cerebri: The dura matter extension that reaches into the gap ‘Right and the Left hemisphere of the Cerebrum. Cerebeli: The dura matter extension that reaches into the between the Right and the Leff divisions of the Cerebellum Support to it Cerebelli: The extension that reaches into the right hemisphere and the right cerebellum hemisphere and extends {i and similarly reaches into the left cerebral hemisphere ‘ef crehelium hemisphere fm Sinwses (DVS): The dural venous sinuses (DVS) are dress lated between the outer and inner layers of yg thence of ymphatc drainage (a drunage system feng xin and waste as well plays many other sem 'n boosting immunity) in the brain places the ‘the means to drain de-oxygenated blood from brain. UNIT BIOLOGICAL BASIS OF BEHAVIOR Sub-arachnoid Space Contains Cerebrospinal Fluid Arachnoid Mater: It is the inner fibrous layer that connects Dura Mater & Pia Mater, It accompanies and supports inner-foldings of the inner dura mater. thas projections present in them called Arachnoid Granulations that diffuse Cerebrospinal Fluid from sub-arachnoid space into the Dura “Mater for re-absorption. Pia Mater: ‘They are the thin fibrous and delicate membrane that is in direct Contact with the brain, It lines the contours of the brain (Gyri and Fissuses), It is impermeable to fluid present in the brain. It contains Choroid Plexus (which is a network of capillaries & ependyma) that produces Cerebrospinal Fluid which is present in the ventricles of the brain Functions of the Meninges: It protects the brain and the spinal cord. It produces CSF which is a shock absorber and maintain uniform pressure. It forms part of the Blood Brain Barrier. : The Meninges li Ce Ney 3e ana, “ the jube extending Lys AND CEREBROSPINAL FEUD the fourth ventricle = The vetisles Fain, called ventricle cing. the SH), Mls protecting } chon space He cavities an the te ah corel Md (¢ fluid (CSE), sbi fils the subar I wal, and the cerebral ventric es 0 the b Tard veniticle Covet awediet Fourth ventncle The CSE serves the folowing functions; Absorbs physical shocks to the brain: The cerebrospinal support and cushions the bran, Patients who have had some cetehyospinal fluid drained away often suffer raging experience stabbing pain each time they jek their + Distributes nutritive materials to and removes: nervous tissue. c * Provides a chemically stable environment, laa eal ceed emcee fone lala od we VENTRICLES: There are four ‘ach of two lateral ventricles (9 aqueduct) and to the central1 AMIT PANWAR 0.00 4g HORMONES “d in the body that release subst are simyormones into the bloodstream, They ee which monitors and controls roughout the body. Exocrine glands se eno te extemal environment UNIT 4: BIOLOGICAL BASIS OF BEHAVIOR Some of the endocrine glands of the endocrine system There a nees. Lndoctine re part of the the release of crete substances many different endocrine glands within the body that all Daticipate in hormon lands include: ated functions. Some examples of endocrine are examples of endocrine glands and their functions sland releases melatonin, which triggers sleep . Pineal gland pituitary gland releases oxytocin to cause contractions Pituitary gland Thyroid gland ——-€9 ———_—_—— apocrine, or BS Thymus Via rupturing | that has a high | | | | can be categorized as holo Holocrine glands release their substances ‘Apocrine glands release a part of themselves ion of their product. Merocrine glands release substances vesicles which leaves the integrity of the cell intact. The are example of exocrine glands and their functions, glands release sweat onto the skin Adrenal gl: 1d aps 2 eS perce glands release saliva —— Ovary lands release milk Testis ——_-f glands are exocrine and endocrine. The pancreas releases insulin two hormones that are important in regulating blood which work in the body to monitor body processes including heart and Exocrine Glands Bete cession Pituitary gland: The pituitary gland is broken up into the anterior itary gland and the anterior pituitary gland. The anterior Pituitary gland has many functions including the release of hormones linked to adrenaline which control a person's fight-or- flight response. The posterior pituitary gland helps create hhormones that monitor water balance in the body, as well as oxytocin (which helps mothers and babies bond after birth), ‘Ovaries and Testes: The ovaries and testes are found in females and males respectfully and are responsible for creating the sex - Endocrine glands do not use ducts to release their products. hormones. These hormones regulate the entire reproductive te) pene process and enable procreation to occur. om ea ae — ofthe on a = Hypothalamus: The hypothalamus produces hormones that Rome ray Ra, jin the __fegulate autonomous processes such as hunger, mood, and ec me rlcmad io ce ee on ___ intemal body temperature, among other things Ststne mc ae ot into the blood sidan, nee © Peal: The pineal gland produces a hormone known as " a. _ melatonin, which helps an individual fall asleep. body is full of structures called glands which are for alarge variety of functions. A gland is an organ in the that produces a substance (such as a chemical) and releases it, ‘can be classified as either: a glands are glands that release their produced substance into the blood stream. Endocrine glands are part of the in system, which is a system of structures within the body that fogether to monitor, produce, and secrete hormones throughout fo release that product, the entire cell ruptures dumped. An example of a holocrine ‘on the shin, pocrine gland concentrates its products its product, it loses the portion 1351 ee hat contiins that prestict The gland eran the potion aan An ¢ A lost an primes ave voce glad the may qa i women, seuretes * Merocrine gland A merocrine exoering gland seen Asta N veiles The substance is ereated within the then expelled in sanall pockets through the eelhular Home Thi helind An example se plans the salivary gla of the mouth, Nasty: Lacs ave passageways tha exocrine grands use io relaaa le ‘st \ fore duct foul av the beay i the canon bile duc, The we vtucing bile and releasing it via endocrine plans have ducts? Rew vt discussed at the begining of the lesson, Endocrine telease “hei products ditwetly inte the bloodstream, ‘Thus, land Vunetion; the endocrine glands rel to the bloodstream, These hormones are chemical “tees the tat or stop of a press within the bay, * hen plucose levels ane high, the punerens lower it During labor the posterior pity gland which causes contractions tuble highlights: some of the " the buidy, what their roke is, ang ‘hem. This list is not exhaustive, Fyocrine Gland Fun socrne glands have multiple fimetions, ae eNereted into the extemal environment, the mouth, the surfice of the skin, the dj Wath such a large diversity: of unction of exocrine glands varies ‘exocrine glands are listed below: * Release of bile and enzymes digestion Sweat released on the surface o cooling Mucous secreted in the trachea Solivary glands releasing start of food breakdown Mammary tissue releasing F rocrine Hormones 4 cre glands donot release iif substances in response + Ungestive exocrine glands work om isan the digestive Salivary glands respond stimulated by heat or stre Mammary glands: