Biological Psychology PDF

BIOLOGICAL PSYCHOLOGY Lesson 1: The Major Issues in Biological Psychology MAJOR ISSUES: THE MIND – BRAIN RELATIONSHIP 1. Biological Explanations of behavior Biological expl...

BIOLOGICAL PSYCHOLOGY Lesson 1: The Major Issues in Biological Psychology MAJOR ISSUES: THE MIND – BRAIN RELATIONSHIP 1. Biological Explanations of behavior Biological explanations of behavior raise the 2. The Mind – Brain Relationship mind-brain problem: “What is the 3. The Genetics of Behavior: relationship between the mind and the o Heredity and Environment brain?” o The Evolution of Behavior DUALISM o Genes and Behavior The belief that minds and body are different kinds of substances that exist BIOLOGICAL PSYHOLOGY independently. It is the study of physiological, evolutionary, o Rene Descartes - proposed that mind and and developmental mechanisms of behavior brain interact at a single point in space, and experience. which he suggested was the pineal gland, The goal is to relate biology to issue of the smallest unpaired structure found in the psychology. brain. It is only not a field of study, but also a point o Nearly all current philosophers and of view. scientists reject the idea of dualism because The proper way to understand behavior is in it conflicts with the law of conservation of terms of how it evolved, and how the matter and energy: matter can transform functioning of the brain and other organs into energy or energy into matter, but control behavior. neither one appears out of nothing, or disappears into nothing. Because matter BIOLOGICAL EXPLANATIONS OF BEHAVIOR alters its course only when matter or energy Physiologic relates the behavior to the acts upon it, a mind that is not composed of al activity of the brain and matter or energy could not make anything other organs. happen. e.g low levels of dopamine cause MONISM a person to experience In contrast, is the belief that the universe involuntary movements in the consists of only one kind of substance. body. Various forms of monism are possible and Ontogenetic how a structure or grouped into the following categories: behavior develops, incl. o Materialism - everything that exists is the influences of genes, material or physical. All psychological nutrition, experiences & experiences can be explained in purely their interactions physical terms. ability to inhibit impulses o Mentalism - the view that only the mind develops gradually from really exists and that the physical world infancy to adolescence could not exists unless some mind were Evolutionary reconstructs the aware of it. evolutionary history of a o Identity Position - the view that mental structure or behavior. processes and certain kinds of brain e.g. goosebumps (hair erection) activities are the same thing. “Every mental make a frightened animal looks experience is a brain activity” or “mental larger. activity is what happens in the brain” Functional describes why a structure We cannot be sure that monism is correct, or behavior evolved as it but it is the most reasonable working did hypothesis. e.g. a camouflaged appearance Stimulation of any brain area provokes an makes an animal inconspicuous experience. to predators thus aiding in its One cannot have a mental activity survival. without a brain activity. BIOLOGICAL PSYCHOLOGY Lesson 1: The Major Issues in Biological Psychology THE GENETICS OF BEHAVIOR medical care, smoked, drank or used GENE – is defined as a portion of a chromosome, drugs). which is composed of a double stranded molecule o Multiplier Effect - genes can also called deoxyribonucleic acid (DNA). influence behavior indirectly by changing DNA – strand of DNA serves as the template for the your environment synthesis of RNA. ▪ How genes affect behavior? RNA - serves as the template for protein molecules. o The gene itself does not cause a Some of these proteins form part of the structure of condition, rather it produces a the body, while others regulate chemical reactions protein that under certain in the body. circumstances increases the HOMOZYGOUS – an identical pair of genes on the probability of the condition two chromosomes o There are certain genes that control HETEROZYGOUS – unmatched/ different pair of brain chemicals. genes. o Genes also effect behavior indirectly, DOMINANT GENES – show strong effect in either by changing the way others in the homozygous or heterozygous conditions. environment treat you. (Eg. People RECESSIVE GENES – shows its effects only in deemed as attractive are more homozygous conditions. confident) AUTOSOMAL GENES – are located on autosomal ▪ Do the observed differences among chromosomes. individuals depend more on differences in SEX LINKED GENES – are located on sex heredity or differences in environment? chromosomes. Y chromosomes have genes for o Many researchers utilized only 27 proteins while an X chromosome has monozygotic and dizygotic twin genes for about 1500 proteins. studies to determine contributions of heredity and environment, as well as Sex Linked and Sex-Limited Genes on adopted children. Biochemical An example of a human Sex limited genes methods have identified certain sex-linked gene is the (present in both sexes) genes to be linked to conditions/ recessive gene for red- are on autosomal behaviors including loneliness, green color deficiency. chromosomes, but neuroticism, TV watching, and social Any man with this gene active mainly on one attitudes. on his X chromosome sex. Examples include experiences this color genes that control THE EVOLUTION OF BEHAVIOR deficiency because he amount of chest hair in Evolution is a change over generations in has no other X men, breast size in the frequencies of various genes in a chromosome. A woman women, amount of population. It includes any change in gene can only be color crowing in roosters and frequency regardless of whether it deficient if she has that rate of egg production in helps/harms species in the long run. recessive gene on both hens of her X chromosomes Any gene that is consistently associated with reproductive success will become more HEREDITY AND ENVIRONMENT prevalent in later generations. o Artificial Selection - a technique Every behavior requires both heredity and used by breeders when they choose environment. Take away either one, and individuals with desired traits and nothing is possible. makes them parents of next o Heredity vs Prenatal Influences - generation. biological children of parents with o Natural Selection - individuals more criminal records are likely to have similar successful than others in finding problems even when they are adopted food, escaping enemies, attracting by excellent parents. The biological mates, protecting their offspring, parents gave them their genes and their then their genes will become more prenatal environment (poor diets, poor prevalent in later generations. BIOLOGICAL PSYCHOLOGY Lesson 1: The Major Issues in Biological Psychology Evolutionary Psychology deals with how IN SUMMARY… behaviors have evolved, especially social behaviors Biological Explanations of behavior: ▪ Is there a gene for altruistic behavior? physiological, ontogenetic, evolutionary, o Among non-humans, altruism toward functional non-relatives is rare in most species. Biological explanations of behavior do not (E.g. chimpanzees, crows) assume that the individual understands o Altruistic groups survive better than the purpose or function of the behavior less cooperative ones Dualism vs. Monism - try to explain mind- o Reciprocal altruism – individuals brain relationship help those who will return the favor No one has found a way to answer the (or extend help to others) “hard problem:” why brain activity is o Kin Selection – in both humans and related to mental experience at all non- humans altruistic behavior is Most behavioral variations reflect the more common towards relatives combined influences of many genes and than towards unrelated individuals. many environmental factors. Heritability is an estimate of the amount of variation that is due to genetic variation as opposed to environmental variation BIOLOGICAL PSYCHOLOGY Lesson 2: The Cell of the Nervous System TOPIC OVERVIEW: INTERNEURON 1. Anatomy of Neurons o if a cell dendrites and axons are contained 2. Types of Glial cells (neuroglia) within a single structure 3. The Blood-Brain Barrier 4. Synapses & Neurotransmitter AFFARENT NEURONS brings information into a structure THE CELLS OF THE NERVOUS SYSTEM carry SENSORY INFO from RECEPTORS in The nervous system is composed of 2 kinds skin/other organs – CENTRAL NERVOUS of cells: neurons and glia (neuroglia) SYSTEM (sensory neuron) NEURON cell bodies are located outside of the spinal cord o Receive information and transmits it to other cells EFFERENT NEURONS carries information away from a structure GLIA Carry MOTOR INFO from BRAIN – PERIPHERAL o do not transmit information over long NERVOUS SYSTEM (motor neuron) distances as neurons do, although they do exchange chemicals with adjacent neurons; cell bodies are located in the ventral horn of provide supportive framework for the NS. the spinal cord. o Every sensory neuron is afferent to the NS, every motor neuron is efferent to the ANATOMY OF NEURON NS. DENDRITES AUTONOMIC DIVISION o branching fibers that receive information Regulates involuntary body responses CELL BODY/SOMA Blood vessels o contains the nucleus, ribosomes, mitochondria; covered with synapses at its SOMATIC DIVISION surface Voluntary movement by skeletal muscles AXON Skeletal muscles o thin fiber that sends info to other neurons or an organ / muscle; has branches at the end NEUROGLIA (presynaptic terminal) GLIA MYELIN SHEATH a (from the Greek word meaning 'glue') hold the neurons together and provide a o covers the axon, interrupted by nodes of supportive framework for the NS; they are Ranvier smaller but more numerous than neuron The following are types of Glia: THREE TYPES OF NEURONS Astrocytes MOTOR NEURON wrap around presynaptic terminals of a o has its soma in the spinal cord; it receives group of functionally related axons. excitation from other neurons and conducts Shields the synapse. impulses along its axon to a muscle Microglia SENSORY NEURON remove waste material viruses, fungi, o highly sensitive to a particular type of microorganisms. stimulation (light/sound/touch) BIOLOGICAL PSYCHOLOGY Lesson 2: The Cell of the Nervous System They also contribute to learning by or inhibit another cell or alter its response removing the weakest synapses. Important to other input in brain damage A single release of neurotransmitter produces only a subthreshold response in Oligodendrocytes (CNS) & Schwann Cells (PNS) the receiving cell. Repeated stimuli within build myelin sheaths that insulate the a brief time have a cumulative effect. vertebrate axons Transmission at synapses goes through many steps, and interference at any of Radial Glia them can alter the outcome Nearly all drugs that affect behavior or o guide migration of neurons during experience do so by acting at synapses embryonic development (PRENATAL) CHARLES SCOTT SHERINGTON THE BLOOD-BRAIN BARRIER o physiologically demonstrated that Although the brain, like any other organs, communication between 1 neuron and the need to receive nutrients from the blood, next differs from communication along a many chemicals cannot cross from the single axon by studying reflexes. blood to the brain. o Inferred the existence of a gap he called the When the immune system identifies a virus, synapse. they kill it & the cell that contain it, however damaged neurons are not replaced To minimize risk of irreparable brain CHEMICAL EVENTS AT THE SYNAPSE damage, the body builds a wall along the sides of the brain's blood vessels to keep T.R ELLIOTT out most viruses, bacteria, harmful chemicals but also nutrients o discovered that applying the hormone Any virus that enters the NS stays their adrenaline directly to the surface of the for life (rabies / chicken pox / shingles / heart, the stomach and pupils produces the genital herpes) same effects as those of the sympathetic Dependent on tight endothelial cell nervous system. junctions; keeps out useful chemicals as o He suggested sympathetic nerves stimulate well as harmful ones muscles by releasing a similar chemical at a Chemicals that pass through the blood-brain synapse barrier are: oxygen, carbon dioxide, OTTO LEOWI chemicals that dissolve in the fats of the membrane (Vit A & D, various drugs) o German physiologist glucose, amino acids, purines, choline, o demonstrated it by stimulating the vagus vitamins iron & a few hormones pass nerve of a frog thereby decreasing its heart through active transport, a protein rate mediated process that expends energy to o he collected fluid from the heart & pump chemicals from the blood into the transferred it to another frog and produced a brain similar effect concluding that nerves send Adult neurons rely heavily on glucose the messages by releasing chemicals only nutrient that can cross bloodbrain barrier in large quantities, thiamine (vitamin B1) is needed to use glucose SYNAPSES At a synapse, a neuron releases neurotransmitters (chemicals) that excite BIOLOGICAL PSYCHOLOGY Lesson 2: The Cell of the Nervous System NEUROTRANSMITTER Fight or flight response; focus Contract blood vessels to increase blood At a synapse, one neuron releases flow chemicals called neurotransmitter that affect Patients with ADHD are often prescribed a second neuron medication that increase levels of Neurotransmitter can either be: noradrenaline in the brain EXCITATORY – can cause neurons to fire action GLUTAMATE potentials (electric signals) Most common neurotransmitter in the brain INHIBITORY – prevent action potentials from being involved in cognitive functions: learning fired and memory ACTION POTENTIAL Regulates the brain development and creation of neve contacts A stimulation past the threshold producing It is toxic to neurons in large quantities depolarization Brain damage and strokes can lead to It activates the neuron creation of harmful excess, killing brain cells o Action potentials play an important role in to cell-to-cell communication. In muscle cells, ENDORPHINES the firing of an action potential can cause a Are range of compounds formed from long muscle contraction. chain of amino acids AMINO ACID – glutamate, GABA, glycine, They are released in the brain during aspartate (contains NH2 - amino radical) exercise, excitement, pain, sexual activity Produces feeling of well-being and NEUROPEPTIDES – chain of amino acids euphoria ACETYLHOLINE – modified amino acid Certain foods (chocolate and spices) can also stimulate release of endorphins MONOAMINES – serotonin, dopamine, epinephrine, norepinephrine EXCITATORY / INHIBITORY PURINES – adenosine NEUROTRANSMITTERS GASES – nitric oxide (increases blood flow) DOPAMINE Pleasure and satisfaction EXCITATORY NEUROTRANSMITTERS Associated with addiction, movement, motivation ADRENALINE (Epinephrine) Natural activities and synthetic substances can trigger release of dopamine Produce in high stress or exciting situations Related to positive symptoms of Stimulates increased heart rate, contracts Schizophrenia (hallucinations and delusions blood vessels, dilates airways, increase due to hyperactive dopamine transmission blood flow to the muscles and oxygen to the in certain areas of the brain) lungs Leads to a physical boost & heightened SEROTONIN awareness EpiPens used to treat allergic reaction, Feeling of well-being and happiness work by injecting adrenaline Regulates sleep-wake cycle and intestinal movements Low levels of serotonin has been linked with NOREADRENALINE (Norepinephrine) depression and anxiety Anti-depressant work by increasing Affects attention and responding actions in serotonin the brain Exercise & light exposure can increase level BIOLOGICAL PSYCHOLOGY Lesson 2: The Cell of the Nervous System ACETYLCHOLINE (telephone) while hormones are like radio stations, they convey message to any Principal neurotransmitter involved in receiver who is turned in thought, leaning, & memory Made up of ductless glands In the body, it activates muscle action Secretes hormones (chemical messengers) Damage to acetylcholine producing areas in directly into blood stream the brain has been linked with memory Over secretion and under secretion of deficits hormones may disrupt normal functioning Associated with attention and enhancement affecting behavior of sensory perception upon waking TYPES OF HORMONES INHIBITORY NEUROTRANSMITTERS PINEAL GLAND GAMMA AMINOBUTYRIC ACID (GABA) Secretes the hormone melatonin which Is a major inhibitory neurotransmitter in regulates the sleep-wake cycle, secreted the brain primarily at night Calms firing nerves in the CNS Melatonin is a mild sedative, signals the Increased levels improve mental focus and body when it is time to sleep relaxation It may affect the onset of puberty & is also Low levels cause anxiety and has been connected with aging linked to epilepsy GABA also contributes to motor control and PITUITARY GLAND vision Master gland Controls the activities of other glands EXCITATORY Controlled by the hypothalamus Growth hormone is somatotrophin ADRENALINE – fight or flight response Secretes vasopressin an antidiuretic NORADRENALINE – concentration hormone which controls water secretion of kidneys GLUTAMATE – memory Oxytocin – stimulates labor, breastfeeding, ENDORPHINS - euphoria attachment the following are the two types of EXCITATORY/INHIBITORY pituitaries: DOPAMINE – pleasure Anterior Pituitary SEROTONIN – mood o Thyroid Stimulating Hormone (TSH) – THYROID ACETYLCHOLINE – learning o Luteinizing Hormone (LH) – OVARIES INHIBITORY o Follicle-stimulating Hormone (FSH) – GONADS GABA – calming o Adrenocorticotropic Hormone (ACTH) – ADRENALS o Prolactin – MILK PRODUCTION HORMONES OF THE ENDOCRINE SYSTEM o Growth Hormone (SOMATOTROPIN) – GROWTH Are chemicals that are secreted by a gland or other cells and conveyed by the blood to Posterior Pituitary other organs, whose activity it influences o Vasopressin Neurotransmitters conveys messages o Oxytocin directly from sender to the receiver BIOLOGICAL PSYCHOLOGY Lesson 2: The Cell of the Nervous System THYROID GLAND Secretes thyroxine which controls metabolism Hyperthyroidism – increased metabolism = irritable and tired, excitability, insomnia, weight loss Hypothyroidism – low levels of thyroxin can cause mental retardation in children known as cretinism ADRENAL GLANDS Secretes corticosteroids which regulate heartbeat, stress resistance and muscle development Cortisol (stress hormone) which regulate metabolism, blood sugar, inflammation Adrenalin or epinephrine which helps arouse body to cope with threats and stress and intensity emotions such as fear and anxiety ISLET OF LANGERHANS Found in the pancreas Secretes insulin that prevents the accumulation of sugar in the blood Under secretion of insulin = increase in blood sugar (hyperglycaemia) SEX GLANDS Gonads of male (testes) produce testosterone that helps produce male secondary characteristics Sex glands of females (ovaries) produce estrogen and progesterone BIOLOGICAL PSYCHOLOGY Lesson 3: Anatomy of the Nervous System TERMS: Referring to Directions COLUMN – set of cells perpendicular to the surface of the cortex with similar properties DORSAL – towards the back, away from ventral, top GANGLION (GANGLIA) – a cluster of neuron cell bodies, usually outside the CNS VENTRAL – toward the stomach, away from dorsal, bottom GYRUS (GYRI) – a protuberance on the surface of the brain ANTERIOR – towards the front end SULCUS (SULCI) – a fold/ groove the separates POSTERIOR – towards the rear end one gyrus from another SUPERIOR – above another part the gyri are the ridges and sulci are the INFERIOR – below another part groves that appear on the wrinkled surface of the brain LATERAL – toward the side, away from the midline FISSURE – a long deep sulcus MEDIAL – toward the midline, away from the side PROXIMAL – located close to the point of origin/ attachment THE NERVOUS SYSTEM DISTAL – located more distant from point of origin/ CENTRAL NERVOUS SYSTEM (CNS) attachment composed of the brain and spinal cord IPSILATERAL – on the same side of the body (e.g. 2 parts on the right) PERIPHERAL NERVOUS SYSTEM (PNS) CONTRALATERAL - on the opposite side of the consists of the nerves outside the brain and body (one on the left and one on the right) spinal cord the following are parts of the PNS: CORONAL PLANE – shows brain structure as seen from the front SOMATIC NERVOUS SYSTEM SAGITTAL PLANE – shows brain structure as o consists of the axons conveying messages seen from the side from the sense organs to the CNS and from the CNS to the muscles HORIZONTAL PLANE – shows brain structures as (voluntary) seen from above (or transverse plane) o carries messages from the CNS to the skeletal muscles that control movements of the body TERMS: Referring to the parts of Nervous o controls skeletal muscles System AUTONOMIC NERVOUS SYSTEM LAMINA – a row or layer of cell bodies separated o controls the heart, intestines & other from other cell bodies by a layer of axons and organs (involuntary) dendrites o largely concerned with involuntary functions TRACT (PORJECTION) – a set of axons within the such as respiration, circulation, and CNS digestion; plays a role in emotion (headache, diarrhea, stomach-ache when NERVE – a set of axons in the periphery/ PNS anxious) (either from CNS to a muscle or from sensory o Prolonged emotional arousal can adversely organ to CNS) affect the true health of the organs controlled by the autonomic nervous system NUCLEUS (NUCLEI) – a cluster of neuron cell (TAKOTSUBO CARDIOMYOPATHY) bodies within the CNS o The following are the subdivisions of Autonomic Nervous System: BIOLOGICAL PSYCHOLOGY Lesson 3: Anatomy of the Nervous System SYMPATHETIC NERVOUS SYSTEM The filled circles represent cell bodies and arrows represent axons o has an activation or arousal function, and it tends to act as a total unit; it mobilizes the H SHAPED GRAY MATTER body; sometimes called the fight-or-flight response In the center of the cord is densely packed o (mobilizes body for action, energy output) with cell bodies and dendrites PARASYMPATHETIC NERVOUS SYSTEM WHITE MATTER o Slows down body processes and maintains Many neurons of the spinal cord send axons a state of tranquillity from the gray matter to the brain or other o (conserves energy maintains quiet state) parts of the spinal cord through the white By working together, the 2 subdivisions can matter which consists mostly of myelinated maintain homeostasis – a delicately axons balanced or constant internal state - Each segment of the spinal cord sends sensory information to the brain & receives THE SPINAL CORD motor commands from the brain - All that information passes through the The spinal cord is the part of the CNS within tracts of axons in the spinal cord the spinal column - If a spinal cord is cut at a given segment the It communicates with all the sense organs brain loses sensation from that segment and muscles except those of the head (the and below. It also loses motor control all face and head are connected to the cranial over parts of the body served by that nerves instead) segment and lower ones It is a segmented structures and each segment has on each side a sensory and motor nerve The spinal cord ends at the L1/L2 vertebrate BELL MAGENDIE LAW The entering dorsal roots (axon bundles) carry sensory information, and the exiting ventral roots carry motor information o The axons from the skin and muscles are the PNS o The cell bodies of the sensory neurons are in a cluster of neurons outside the spinal cord, called dorsal root ganglia RELATIONSHIP OF SENSORY AND MOTOR NEURONS TO THE SPINAL CORD Schematic representation of the spinal cord at the thoracic level. Sensory neurons enter the dorsal horn of the spinal cord from the dorsal root ganglion through the dorsal root, with collaterals (green arrows) extending up to the brain. Motor neurons exit the ventral horn of the spinal cord at the ventral root. BIOLOGICAL PSYCHOLOGY Lesson 3: Anatomy of the Nervous System THE BRAIN activities such as motor control, pain perception, rhythmic contractions, and the sleep-wake cycle The CNS develops from three regions of the early embryonic brain called the forebrain The posterior part of the brain that (prosencephalon), midbrain consists of the 3 parts: (mesencephalon), and hindbrain MEDULLA / MEDULLA OBLONGATA (rhombencephalon). The forebrain gives rise to the adult Helps to control vital reflexes including cerebrum and diencephalon breathing, HR, vomiting, salivation, The midbrain gives rise to the adult coughing & sneezing through the cranial midbrain nerves (which controls sensation & The hindbrain gives rise to the adult pons, movement from the head) cerebellum, and medulla oblongata o Pathway for ascending and descending nerve tracts; center for several important reflexes (e.g. heart rate, breathing, swallowing, vomiting) PONS Lie anterior & ventral to the medulla, contains nuclei of some cranial nerves, ‘bridge’ axons in the pons across from 1 side of the brain to the other. o Contains ascending and descending nerve tracts, relays information between cerebrum and cerebellum o site of reflex centers CEREBELLUM Movement, motor coordination and balance, processing visual & auditory stimuli. o Controls muscle movement and tone; THE MAJOR DIVISIONS OF THE BRAIN governs balance and regulate extent of THE HINDBRAIN intentional movement o It involved in learning motor skills Aka rhombencephalon: known as the ‘parallelogram brain’. (metencephalon, THE CRANIAL NERVES myelencephalon) Legend: Red (eye movements) 3,4,6 The lowest portion of the brain where the spinal cord rises to meet the brain Green (taste, tongue, throat) 7,9,12 The medulla, pons, midbrain & certain I. Olfactory (smell) central structure of the forebrain make up II. Optic (vision) the brainstem. III. Oculomotor (eye movements / pupil BRAINSTEM – connect the spinal cord to the constriction) cerebrum; consists of the medulla oblongata, pons, IV. Trochlear (eye movements) and midbrain, with the reticular formation scattered V. Trigeminal (skin sensation from the throughout the three regions; has many important face) functions, as listed under each subdivision; is the VI. Abducens (eye movements) location of cranial nerve nuclei VII. Facial (taste from anterior 2/3 of tongue, facial expression, salivation) RETICULAR FORMATION – scattered throughout the brainstem and controls many brainstem BIOLOGICAL PSYCHOLOGY Lesson 3: Anatomy of the Nervous System VIII. Statoacoustic / Vestibulocochlear CEREBRUM – controls perception, thought, (hearing and equilibrium) memory, emotion, and conscious motor activity and IX. Glossopharyngeal (taste from posterior can override most other systems. Located in 1/3 of tongue, swallowing, throat telencephalon. movements during speech) X. Vagus (sensations from neck, control of THE FOREBRAIN: Telencephalon throat, esophagus, larynx, parasym, The major structures are cerebral cortex, nerves of stomach/ intestines) hippocampus (located in the limbic XI. Accessory (neck and shoulder system), and basal ganglia movements) The outer portion is the cerebral cortex XII. Hypoglossal (control of muscles of the (cerebrum). tongue Under it are the other structures like diencephalon (thalamus & hypothalamus) THE MIDBRAIN THE CEREBRAL CORTEX Aka mesencephalon: known as the Where the highest mental functions such as ‘middle-brain’ thinking and planning takes place The midbrain is the middle of the brain, o The cell bodies (soma) of the cerebral surrounded and dwarfed by the forebrain cortex are gray matter, and their axons It consists of 5 parts: extending inward are the white matter TECTUM o Neurons in each hemisphere communicate through a bundle of axons called corpus Roof of the midbrain callosum The swelling on each side of the tectum are HEMISPHERE – wrinkled surface of the cerebral superior colliculus and inferior colliculus cortex. Each hemisphere is subdivided into 4 SUPERIOR COLLICULUS regions or lobes: Process information for vision Frontal Lobe INFERIOR COLLICULUS Contains primary motor cortex (control of movements) and prefrontal cortex (receives Process information for hearing / audition information from all the sensory system, working memory) TEGMENTUM Associated to planning, judgement, Intermediate level of the midbrain that adapting to new situations, flexibility of covers several other midbrain structures behavior and personality It contains nucleus for III & IV cranial Prefrontal Lobotomies – cutting the nerves (eye movement) prefrontal cortex from other parts of the cortex resulted in tamer behaviors, apathy, SUBSTANTIA NIGRA loss of ability to plan/take initiative, memory Gives rise to the dopamine containing disorders, distractibility, and loss of pathway that facilitates readiness for emotional expression movement Temporal Lobe Lateral portion of each hemisphere THE FOREBRAIN Processes auditory info and complex visual info (perception of movement, recognition of Aka Prosencephalon (forward-brain), faces) Telencephalon (end-brain), Diencephalon (between-brain), Wernicke’s area (left temporal lobe) – is responsible for understanding spoken language and damage to this area can BIOLOGICAL PSYCHOLOGY Lesson 3: Anatomy of the Nervous System cause Wernicke’s Aphasia (trouble THE VENTRICLES understanding speech, writing, and sign language) The CNS begins its development as a tube a tumor in a temporal lobe may cause surrounding a fluid canal elaborate visual and auditory hallucinations The canal persists into adulthood at the it plays a role in emotional and motivational central canal – a fluid filled chanel at the behaviors center of the spinal cord, and as the Broca’s area (right) & Wernicke’s area ventricles (4 fluid filled cavities within the (left): both are important for language brain) Cells called choroid plexus inside the 4 Parietal Lobe ventricles produce cerebrospinal fluid (CSF) – a clear fluid similar to blood plasma Lies between the occipital lobe and central CSF fills the ventricles, and some of it flows sulcus to the into the central canal of the spinal It contains the primary somatosensory cord. Most of the CSF goes into the narrow cortex (processes touch sensations) between the brain and thin meninges Involved in registering spatial location, (membranes that surround the brain & attention and motor control spinal cord) Occipital Lobe Meningitis - inflammation of the meninges is very painful because of presence of pain Located at the posterior end of the cortex receptors at this area Contains primary visual cortex CSF cushions the brain and provides A stroke or wound in this area can cause buoyancy cortical blindness Hydrocephalus - when the flow of CSF is obstructed, it accumulated within the LIMBIC SYSTEM ventricles increasing pressure on the brain, a loosely connected network of structures causing the spread of skull bones under the cerebral cortex, important in memory and emotions. Two principal structures are: THE FOREBRAIN: Diencephalon Amygdala - involved in the discrimination of The major structures are the thalamus and objects necessary for survival, (e.g. appropriate hypothalamus food, mate’s social rivals, also connected to Connects the brainstem to the cerebrum; aggressive behavior) has many relay and homeostatic functions as listed under each subdivision Hippocampus – storage of memories THALAMUS BASAL GANGLIA Most sensory input is received here then a group of subcortical structures lateral to sends to the cerebral cortex the thalamus; includes 3 major Major sensory relay center and influences structures: caudate nucleus, putamen, mood and movement globus pallidus o In conditions like Parkinson's & Huntington's HYPOTHALAMUS disease, the basal ganglia deteriorate which result in impaired movement, depression, small area at the base of the brain ventral to deficits of memory, reasoning and attention thalamus o increase the vigor of selected actions conveys message to the pituitary gland, o learning and remembering skills and habits controls feeding, drinking, temperature o learning that develops gradually with regulation and sexual behavior (Hormone extended experience Control) BIOLOGICAL PSYCHOLOGY Lesson 3: Anatomy of the Nervous System major control center for maintaining hemispheres, 4 (lobes) and the structures homeostasis and regulating endocrine beneath it are the thalamus, hypothalamus, function limbic system (hippocampus, amygdala) basal ganglia and ventricles that produce SUBTHALAMUS cerebrospinal fluid Contains nerve tracts and nuclei Each structure of the brain is responsible for different processes and functions EPITHALAMUS Contains nuclei involved in motivation and reward behavior, and contains pineal gland THE FOREBRAIN: Prosencephalon/ Telencephalon The most anterior & prominent part of the mammalian brain Consists of 2 cerebral hemispheres - each organized to receive sensory information from the contralateral side of the body & control muscles on the opposite side by way of axons to the spinal cord and the cranial nerve nuclei. IN SUMMARY… To study the nervous system, one has to be familiar with various terminologies that pertain to different locations and parts / structure of the brain The nervous system is composed of the CNS (brain & spinal cord) and PNS (the nerves outside the CNS) which have a somatic and autonomic function (sympathetic & parasympathetic divisions) Each segment of the spinal cord sends sensory information to the brain & receives motor commands from the brain The brain has 3 major divisions: the hindbrain, midbrain and forebrain The hindbrain (metencephalon) contains the medulla, pons & cerebellum involved in processing information from the cranial nerves, motor coordination, balance and other vital survival processes The midbrain (mesencephalon) contains the tectum, tegmentum, superior and inferior colliculus and substantia nigra The forebrain (telencephalon) is the most prominent part of the mammalian brain which contains the cerebral cortex (2