Transcript Chapter 2
Chapter 2 The Brain and Behavior 1 Copyright McGraw-Hill, Inc. 2010 Chapter Preview The Nervous System Neurons Structures of the Brain and Their Functions The Endocrine System Brain Damage, Plasticity, and Repair Genetics and Behavior 2 Copyright McGraw-Hill, Inc. 2010 Nervous System Electrochemical communication circuitry Billions of interconnected cells Neuroscience Neuroscientists 3 Copyright McGraw-Hill, Inc. 2010 Nervous System: Characteristics Complexity Integration Adaptability 4 Plasticity Electrochemical Transmission Copyright McGraw-Hill, Inc. 2010 Nervous System: Pathways Afferent Nerves Efferent Nerves Motor nerves Information out of brain and spinal cord Neural Networks 5 Sensory nerves Information to brain and spinal cord Integration of sensory input and motor output Copyright McGraw-Hill, Inc. 2010 Nervous System: Divisions 6 Copyright McGraw-Hill, Inc. 2010 Nervous System: Primary Divisions Central Nervous System (CNS) Brain and Spinal Cord Peripheral Nervous System (PNS) Network of nerves connecting CNS to body Two subdivisions: 7 Somatic Nervous System Autonomic Nervous System Copyright McGraw-Hill, Inc. 2010 Nervous System: PNS Divisions Somatic Nervous System Sensory information from skin and muscles to CNS Autonomic Nervous System Messages to and from internal organs Two subdivisions: 8 Sympathetic Nervous System arousing Parasympathetic Nervous System calming Copyright McGraw-Hill, Inc. 2010 Nervous System: Stress “Fight or Flight” Reaction Corticosteroids 9 Function of sympathetic nervous system Stress hormones Acute stress is momentary. Chronic stress is continuous. Copyright McGraw-Hill, Inc. 2010 Nervous System: Cells 10 Neurons Nerve cells Information processing Glial cells Support Nutritional benefits Copyright McGraw-Hill, Inc. 2010 Neurons: Structure Cell Body Dendrites Fibers projecting from neuron Axon Contains nucleus Carries information from cell body toward other cells Myelin Sheath 11 Layer of fat cells, encasing and insulating most axons Copyright McGraw-Hill, Inc. 2010 Neurons: Structure 12 Copyright McGraw-Hill, Inc. 2010 Neural Impulse Resting potential 13 Stable, negative charge of inactive neuron Copyright McGraw-Hill, Inc. 2010 Neural Impulse Action Potential 14 Brief, positive electrical charge, or firing Abides by the all-or-nothing principle Copyright McGraw-Hill, Inc. 2010 Synapses & Neurotransmitters Synapses Space between neurons (synaptic gap) Neurotransmitters 15 Stored in synaptic vesicles (sacs) within terminal buttons Chemical signals which allow electrical impulses to cross synaptic gaps Copyright McGraw-Hill, Inc. 2010 Synapses & Neurotransmitters 16 Copyright McGraw-Hill, Inc. 2010 Neurochemical Messengers Neurotransmitters are excitatory, inhibitory, or both. Acetylcholine (ACh) Stimulates firing of neurons Involved in action of muscles, learning, memory Alzheimer disease: ACh deficiency Gamma aminobutyric acid (GABA) 17 Keeps many neurons from firing Anxiety: Low levels of GABA Copyright McGraw-Hill, Inc. 2010 Neurochemical Messengers Norepinephrine Inhibits firing of neurons in CNS Excites heart muscle, intestines, urogenital tract Depression: Too little norepinephrine Agitated, manic states: Too much norepinephrine Dopamine 18 Helps to control voluntary movement Affects sleep, mood, attention, learning, rewards Parkinson disease: Low levels of dopamine Schizophrenia: High levels of dopamine Copyright McGraw-Hill, Inc. 2010 Neurochemical Messengers Serotonin Endorphins Involved in regulation of sleep, mood, attention, learning Depression: Lowered levels of serotonin Natural opiates that mainly stimulate firing of neurons Shield body from pain Elevate feelings of pleasure Oxytocin 19 Hormone and neurotransmitter Important role in experience of love and social bonding Copyright McGraw-Hill, Inc. 2010 Drugs & Neurotransmitters Drugs influence behavior mainly by interfering with neurotransmitters. Agonist Drug that mimics or increases effects of neurotransmitter Antagonist 20 Drug that blocks effects of neurotransmitter Copyright McGraw-Hill, Inc. 2010 Neural Networks 21 Copyright McGraw-Hill, Inc. 2010 Studying the Brain Brain Lesioning Staining Dyes neurons for tracking neural impulses Electrical Recording 22 Determines effects of brain tissue disruption on behaviors Detects brain wave activity Copyright McGraw-Hill, Inc. 2010 Brain Imaging X-ray two-dimensional images CT (or CAT) scan three-dimensional images PET scan metabolic changes MRI brain structure f MRI brain function 23 Copyright McGraw-Hill, Inc. 2010 Organization of the Brain Hindbrain Midbrain Rises above hindbrain Forebrain 24 Adjacent to top part of spinal cord Uppermost region of brain Copyright McGraw-Hill, Inc. 2010 Organization of the Brain 25 Copyright McGraw-Hill, Inc. 2010 Hindbrain Medulla Cerebellum Controls vital functions, such as breathing and heart rate Regulates reflexes Plays important role in motor coordination Pons 26 Involved in sleep and arousal Copyright McGraw-Hill, Inc. 2010 Midbrain Brain stem Includes much of hindbrain (but not cerebellum) and midbrain Determines alertness Regulates basic survival functions Reticular Formation 27 Involved in stereotyped patterns of behavior, such as walking and sleeping Copyright McGraw-Hill, Inc. 2010 Forebrain Limbic System Thalamus Basal Ganglia Hypothalamus Cerebral Cortex 28 Copyright McGraw-Hill, Inc. 2010 Forebrain: Limbic System Important in both memory and emotion Two principal structures Amygdala Hippocampus 29 Involved in discrimination of objects necessary for survival Has special role in storage of memories Copyright McGraw-Hill, Inc. 2010 Forebrain: Thalamus & Basal Ganglia Thalamus Serves as relay station for information Basal Ganglia 30 Works with cerebellum and cerebral cortex to control and coordinate voluntary movements Copyright McGraw-Hill, Inc. 2010 Forebrain: Hypothalamus Monitors . . . eating, drinking, sex emotion, stress, reward Helps direct endocrine system Regulator of body’s internal state Involved in pleasurable feelings 31 Copyright McGraw-Hill, Inc. 2010 Forebrain: Cerebral Cortex Occipital lobes Temporal lobes Personality, intelligence, control of voluntary muscles Parietal lobes 32 Hearing, language processing, memory Frontal lobes Responding to visual stimuli Registering spatial location, attention, motor control Copyright McGraw-Hill, Inc. 2010 Forebrain: Cerebral Cortex Somatosensory Cortex Motor Cortex Located just behind frontal lobes Processes information about voluntary movement Association Cortex 33 Located at front of parietal lobes Processes information about body sensations Makes up 75% of cerebral cortex Integrates information Copyright McGraw-Hill, Inc. 2010 Forebrain: Cerebral Cortex 34 Copyright McGraw-Hill, Inc. 2010 Cerebral Hemispheres Corpus Callosum Left Hemisphere Receives information from right side of body Language processing, such as speech and grammar Right Hemisphere 35 Large bundle of axons connecting brain’s two hemispheres Relays information between two sides Receives information from left side of body Processing non-verbal information, such as spatial perception, visual recognition, and emotion Copyright McGraw-Hill, Inc. 2010 Cerebral Hemispheres 36 Copyright McGraw-Hill, Inc. 2010 Endocrine System Endocrine System Glands Set of glands that regulate activities of certain organs Organs or tissues that create chemicals that control bodily functions Hormones 37 Chemical messengers produced by endocrine glands Copyright McGraw-Hill, Inc. 2010 Endocrine System Pituitary Gland Controls growth and regulates other glands Thyroid & Parathyroid Glands Adrenal Glands Pancreas Regulate mood, energy level, and ability to cope with stress Performs both digestive and endocrine functions Ovaries (in women) & Testes (in men) 38 Produce hormones related to sexual development and reproduction Copyright McGraw-Hill, Inc. 2010 Brain Damage, Plasticity, and Repair Collateral Sprouting Substitution of Function Damaged region’s function is taken over by another brain area. Neurogenesis 39 Axons of healthy neurons adjacent to damaged cells grow new branches. New neurons are generated. Copyright McGraw-Hill, Inc. 2010 Brain Tissue Implants Brain grafts Stem cells 40 Implants of healthy tissue into damaged brains Primitive cells with capacity to develop into most types of human cells Copyright McGraw-Hill, Inc. 2010 Genetics and Behavior Chromosomes DNA (deoxyribonucleic acid) Complex molecule that carries genetic information Genes 41 Threadlike structures containing DNA Units of hereditary information Copyright McGraw-Hill, Inc. 2010 Genetics and Behavior 42 Copyright McGraw-Hill, Inc. 2010 The Study of Genetics Dominant-Recessive Genes Principle If one gene in pair is dominant and one is recessive, dominant gene overrides recessive gene. Polygenic Inheritance 43 Influence of multiple genes on behavior Copyright McGraw-Hill, Inc. 2010 The Study of Genetics Molecular Genetics Genome Manipulation of genes using technology to determine their effect on behavior Complete set of genetic instructions for making an organism Human Genome Project 44 International research program mapping human genome Copyright McGraw-Hill, Inc. 2010 The Study of Genetics Selective Breeding Behavior Genetics Genetic method use to demonstrate importance of genetic influence on behavior Study of degree and nature of heredity’s influence on behavior Twin Studies 45 Identical vs. Fraternal Twins Minnesota Study of Twins Reared Apart (1996) Copyright McGraw-Hill, Inc. 2010 Genes and the Environment Genotype Phenotype Genetic heritage Observable characteristics Influenced by genotype and environmental factors Genetic Expression 46 Activity of genes is affected by their environment. Copyright McGraw-Hill, Inc. 2010