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Prologue to Chapter 3. Fritz and Hitzig’s Prussian War brain research on triagged soldiers Legal controversies surrounding “brain death” The biological communications and control centers are central to an understanding of human behavior. Nervous System: The biological control center.
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Prologue to Chapter 3 • Fritz and Hitzig’s Prussian War brain research on triagged soldiers • Legal controversies surrounding “brain death” • The biological communications and control centers are central to an understanding of human behavior Psych 101 BHC
Nervous System: The biological control center • The nervous system is both a powerful computer and a complex communications system. • There are multiple inputs to the system • The system conducts multiple internal processes • There are multiple internal and external outputs Psych 101 BHC
The Nervous System • Neurons: the basic units of the nervous system • Parts of the neuron • Axon • Dendrite • Cell body or “soma” Psych 101 BHC
Neurons and synapse Psych 101 BHC
The Nervous System • Neural transmission • individual cells (neurons) transmit bioelectrical energy along the length of the neuron • electrolytes • action potential • resting potential • individual cells (neurons) transmit bioelectrical energy between neurons at the synapse Psych 101 BHC
The Nervous System • Synaptic transmission • chemical substances transmit neural messages across synapses (small spaces between individual neurons) • receptor sites on dendrites • transmitter sites on synaptic knob • neural transmitters include acetylcholine, serotonin, dopamine, epinephrine, norepinephrine, endorphins, enkephalins Psych 101 BHC
Divisions of the nervous system • Divisions of the central nervous system • The Brain • The Spinal Cord • Divisions of the peripheral nervous system • Somatic division of the peripheral nervous system • Autonomic division of the peripheral ner. sys. • sympathetic nervous system • parasympathetic nervous system Psych 101 BHC
Structures and functions of the brain • Brain imaging techniques • non-invasive techniques include the EEG, CAT, PETT, and the MRI • EEG: Electroencephalograph • CAT: Computerized Axial Tomography • PETT: Positron Emission Transaxial Tomography • MRI: Magnetic Resonance Imagery Psych 101 BHC
CAT Scan in progress Psych 101 BHC
Magnetic Resonance Imaging (MRI) through the skull looking at lower brain and brain stem Psych 101 BHC
Structures and functions of the brain • The hindbrain and midbrain: housekeeping and reflex functions • cerebellum: motor coordination and non-thoughtful body movement and smooth movement • brain stem: responsible for maintenance functions, e.g., heart beat, breathing • reticular activating system: in the brain stem, regulates paying attention to new stimuli, waking, sleeping, and daydreaming Psych 101 BHC
Anterior View of Brain Psych 101 BHC
Lateral View: Right Hemisphere Psych 101 BHC
Structures and functions of the brain • Forebrain: cognition, motivation, and action • Cerebral cortex: sensory, cognitive, and motor functions • Hemispheres of the cerebral cortex • right and left hemispheres • hemispheres connected by corpus callosum • some hemispheric functions are shared; some very different functions occur in each hemisphere • Roger Sperry’s split brain research Psych 101 BHC
Structures and functions of the brain • Lobes of the cerebral cortex • frontal lobes • parietal lobes • temporal lobes • occipital lobes • Specialized “cortices” in each of the four lobes Psych 101 BHC
Transverse Section: Looking Right Psych 101 BHC
Cross - section looking down from the top of the brain Psych 101 BHC
Structures and functions of the brain • The Limbic System (on top of the brain stem) and emotion • Hypothalamus • intimately involved in our motives and emotion • instructs the pituitary gland (master gland) to release hormones • Thalamus • primaryily a switching station for incoming/outgoing neural messages • also involved in memory formation Psych 101 BHC
Limbic System Psych 101 BHC
Structures and functions of the brain • The brain is an interacting system • though many separate parts, these parts work together in intellectual and emotional processing • inputs, internal processes, and outputs identify the brain as a complex computer and communications system Psych 101 BHC
Exploded View of Brain Psych 101 BHC
Endocrine system • The endocrine system entails chemical messengers of the body consisting of a number of glands that secrete hormones into the bloodstream • The Pituitary Gland • sometimes called the “master gland” • helps to regulate the activity of the other glands in the endocrine system Psych 101 BHC
Endocrine system • The Adrenal Glands • play an important role in emotional arousal, metabolism, and sexualarousal/functioning • located in the back on top of the kidneys • Islets of Langerhans • located in the pancreas • regulates blood sugar levels by means of secreting both glucagon and insulin • diabetes, hypoglycemia, and mood changes Psych 101 BHC
Endocrine system • Gonads • gonads produce sex cells (sperm, egg) and secrete sex hormones • male: testosterone and androgens • female: estrogen and progesterone • Thyroid gland • regulates metabolism and growth via hormone called thyroxin located in the neck • Cretinism and iodinized salts Psych 101 BHC
Endocrine system • Parathyroid gland • helps to control excitability of nervous system by secreting parathormone • similar to a “squelch” on a radio only this is in the nervous system • Pineal gland • located in the brain, secrets hormone called melatonin, regulates sleep/wake cycles • melatonin associated with prolonged life in rats Psych 101 BHC
Genetic influences on behavior • What is inherited? • the influence of genes and environment on behavior • psychologists try to determine what are the genetic and what are the environmental influences on behavior • evidence suggests schizophrenia, antisocial behavior, and manic depression may be of genetic origin • Implications of genetic behaviors? Psych 101 BHC
Genetic influences on behavior • Biological mechanisms of inheritance: the genetic code • inheritance operates through genes found in the nuclei of human cells • Genes and chromosomes • What is DNA? • What is a gene? • What is a chromosome? Psych 101 BHC
Segment of DNA Psych 101 BHC
Genetic influences on behavior • Biological mechanisms of inheritance • Dominant and recessive traits • dominant genes reveal their traits in the phenotype whenever the gene is present • recessive genes may or may not reveal their traits in the phenotype depending on whether there is a single or double recessive gene for a given trait • eye color, hair color, finger length, etc. are determined by dominant/recessive genes Psych 101 BHC
Genetic influences on behavior • Biological mechanisms of inheritance • Sex-linked genetic traits • operate according to what is and what is not present genetically on the 23rd chromosomal pair. In females this is the XX and, in males, the XY chromosomal pattern • males are more likely to have sex-linked genetic defects (1 in 20); females not (1 in 1000) • examples include hemophilia, male pattern baldness, muscular dystrophy, etc. Psych 101 BHC
Genetic influences on behavior • Biological mechanisms of inheritance • Polygenetic inheritance: many genes having an effect on one single trait, e.g., intelligence • Pleiotropic inheritance: one gene affecting many traits, e.g., Down’s Syndrome • Chromosomal abnormalities • e.g., Kleinfelter’s syndrome, Turner’s syndrome, and XYY (supermale) syndrome Psych 101 BHC
Research on inheritance in humans • Studies of twins • monozygotic vs dizygotic twins and inheritance • using different types of twins to determine genetic vs environmental effects on behavior and traits • Adoption studies • monozygotic twins separated at birth allow for determination of environmental effects • reveal genes have strong behavioral influences Psych 101 BHC
Research on inheritance in humans • Role of inheritance in personality and abnormal behavior • concordance studies show that about 80% probability exists if one monozygotic twin develops schizophrenia that the other will also • both normal and abnormal aspects of personality are influenced by inheritance • e.g., alcoholism, drug abuse, risk-taking Psych 101 BHC
Applications of psychology • Alzheimer’s disease caused by severe atrophy of brain; results in slow but progressive loss of personality and intellectual functioning • Acetylcholine deficiencies and Alzheimer’s disease • Neural transmission and disease processes Psych 101 BHC
Applications of psychology • Schizophrenia research • Dopamine excesses and schizophrenia • L-DOPA, Parkinson’s Disease, and schizophrenia • Excessive dopamine receptor sites in the brain in some schizophrenic persons • Pharmacology and mental illnesses Psych 101 BHC
Applications of psychology • Pharmacology, abnormal behavior, and the future of treatment of mental disorders • within a century it is likely that there will be very little abnormal behavior due to neurotransmitter/receptor aberations • pharmacological advancements suggest that moods, thoughts, and even learning can be influenced by various drugs Psych 101 BHC
Questions? • Any questions on chapter 3? Psych 101 BHC