Week 2 -The Brain and nervous system SV

Week 2 -The Brain and nervous system SV - The Neuron and...

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Unformatted text preview: The Neuron and the The Neuron and the Nervous System Central Nervous System(CNS) The Body’s Communication Networks The Body’s Communication Networks The Nervous System The network of nerves contained within the brain and spinal cord The PNS comprises the somatic and autonomic nervous systems Peripheral Nervous System(PNS) The Body’s Communication The Body’s Communication Networks Divisions of the Nervous System The Body’s Communication Networks The Body’s Communication Networks The Endocrine System Endocrine system: Ductless glands that regulate growth, reproduction, metabolism, mood, and some behavior. Hormones: Chemical messengers secreted into the bloodstream. The Neuron The Neuron Neurons Sensory Neurons Nerve cells that serve as the building blocks of the nervous system Neurons that send signals from the senses, skin, muscles, and internal organs to the CNS Neurons that transmit commands from the CNS to the muscles, glands, and organs Motor Neurons The Neuron The Withdrawal Reflex The Structure of a Neuron The Neuron The Neuron Action Potential The Neuron in Action The Neuron The Neuron Threshold An electrical impulse that surges along an axon, caused by an influx of positive ions in the neuron The level of stimulation needed to trigger an action potential Chemical messengers that transmit information by crossing the synapse from one neuron to another Neurotransmitters How Neurons Communicate The Neuron The Neuron Impulse releases neurotransmitter from axon terminals. Neurotransmitter enters synaptic gap. Neurotransmitter binds to receptors on the receiving neuron. Major Neurotransmitters Major Neurotransmitters Acetylcholine (ACh) Dopamine Endorphine Norepinephrine Serotonin GABA Links motor neurons and muscles. Also facilitates learning and memory. Alzheimer’s patients have an undersupply of ACh. Concentrated in the brain, it is linked to muscle activity. A shortage can cause Parkinson’s disease; an excess of dopamine receptors is linked to symptoms of schizophrenia Distributed throughout the CNS, these natural opiates relieve pain. Widely distributed in the CHS, it increases arousal. Too much may produce a manic state; too little may lead to depression Produced in the brain, it lowers activity level and causes sleep. Too little is linked to depression. Produced in the brain, it lowers arousal and reduces anxiety. It is the main inhibitory neurotransmitter in the nervous system. Receptors and Drugs Receptors and Drugs Anti­depressants: SSRIs ­ Block reuptake of serotonin SNRIs ­ Block reuptake of serotonin and norepinephrine Tricyclics ­ Block reuptake of serotonin and norepinephrine MAOIs ­ Block the enzyme monoamine oxidase, which breaks down dopamine, serotonin, and norepinephrine Slow the CNS by binding to GABA receptors Slow the CNS by affecting GABA receptors Binds to nicotonic receptors and increases dopamine levels in the brain Benzodiazepines: Alcohol: Nicotine: Heroin: Heroin: Ecstasy (MDMA): Cocaine: LSD: Binds to opioid receptors (decrease pain perception, relief of anxiety, intense euphoria) Blocks the reuptake of, and releases, serotonin Blocks reuptake of dopamine, norepinephrine, and serotonin Binds to dopamine receptors, adrenoreceptor receptors, and some serotonin receptors. Increases the release of glutamate, which excites the cerebral cortex The Brain and The Brain’s The Brain and The Brain’s Capacity for Specialization, Integration, Growth and Repair Tools of Behavioral Neuroscience Electroencephalogram •An instrument (EEG) used to measure electrical activity in the brain through electrodes placed on the scalp The Brain The Brain Tools of Behavioral Neuroscience Positron Emission Tomography The Brain The Brain Radioactive isotopes (small amounts) are placed in the blood. Sensors detect radioactivity. Different tasks show distinct activity patterns. A visual display of brain activity, as measured by the amount of glucose being used Tools of Behavioral Neuroscience The Brain The Brain Magnetic Resonance Imaging A brain­imaging technique that uses magnetic fields and radio waves to produce, clear three­dimensional images The Brain Regions of the Brain Regions of the Brain Medulla The Brainstem Vital involuntary Pons The Brain The Brain functions Reticular formation Sleep and arousal Sleep, arousal, attention Cerebellum Motor coordination Thalamus Regions of the Brain The Brain The Brain Amygdala Sensory relay station Fear, anger, and aggression Memory formation Regulates glands, autonomic NS The Limbic System Hippocampus Hypothalamus The Cerebral Cortex in Animals Regions of the Brain The Brain The Brain •The outermost covering of the brain, largely responsible for higher-order mental processes The Four Lobes of the Cerebral Cortex Regions of the Brain The Brain The Brain Regions of the Brain Within the Lobes of the Cerebral Cortex Are: The Somatosensory Cortex The Brain The Brain The Motor Cortex Receives sensory information The Association Cortex Sends impulses to voluntary muscles Houses the brain’s higher mental processes The Somatosensory and Motor Areas Broca’s Area Regions of the Brain The Brain The Brain Wernicke’s Area Located in the left hemisphere, directs the muscle movements in speech production Located in the left hemisphere, involved in the comprehension of language Language Processing The brain operates as an integrated system. A bundle of nerve fibers that connects the left and right hemispheres If surgically severed for treatment of epilepsy, hemispheres cannot communicate directly. The Split Brain The Corpus Callosum A bundle of nerve The Brain The Brain The Split Brain Both eyes send Visual Processing information to both hemispheres. Images in the right half of the visual field go to the left hemisphere. Images in the left half of the visual field go to the right hemisphere. The Brain The Brain Sperry’s Split­Brain Experiment The Split Brain The Brain The Brain Split­brain subjects could not name objects shown only to the right hemisphere. If asked to select these objects with their left hand, they succeeded. The left hemisphere controls speech, the right does not. Brighter areas indicate higher activity levels. When hearing words, for example, auditory cortex and Wernicke’s area are the most active. The Talking Left Hemisphere The Split Brain The Brain The Brain A patient with a stroke in the right hemisphere was asked to copy the drawings. Typical of neglect syndromes, the left side of the model is almost completely ignored. The Split Brain The Brain The Brain Neglect Syndrome The Brain’s Capacity for Growth & Reorganization Plasticity Prospects for the Future Prospects for theFuture Richer environments lead to heavier, thicker brains, more synapses, and better learning. The cost of plasticity is the case of the phantom limb. A capacity to change as a result of experience The Nature­Nurture Debates The Nature­Nurture Debates The Pursuit of Heritability Nature­Nurture Debate Heritability The debate over the extent to which human behavior is determined by genetics and the environment. A statistical estimate of the percentage of the variability of a trait within a group that is attributable to genetic factors. The Nature­Nurture Debates The Nature­Nurture Debates Genetic Influences Based on the Minnesota personality studies: When raised together, monozygotic twins are more similar than dizygotic twins. Twins raised apart are almost as similar to each other as those living in the same home. The Nature­Nurture Debates The Nature­Nurture Debates Heritability of Various Human Attributes Genetic Influences The role of genetic factors is shown by the extent to which identical twins are more similar to each other than are fraternal twin pairs. A correlation closer to one indicates greater similarity. The Nature­Nurture Debates The Nature­Nurture Debates Heritability of This study involved 672 Attitudes twins who rated their attitudes on various issues and activities. The results show some influence of genetic factors. Genetic Influences The Nature­Nurture Debates The Nature­Nurture Debates The studies of twins and adoptees also support the importance of environmental influences. Environmental Influences Genetic differences typically account for less than 50 percent of the variation in personality. Environmental factors account for the rest of the variation. Nonshared environments play a vital role in a person’s development and may be equally, or more, significant compared to shared environments. The Brain on Drugs The Brain on Drugs http://youtu.be/of0TiyXWhOk ...
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