1. Chapter 2Neuroscience

2. Brain and MindT h e P e r s o nT h e B r a inP h y s i c a lT h e M i n dP s y c h o l o g i c a l 3. Topics to Explore1. The Neuron2. The Peripheral Nervous System3. The Central Nervous System 4. Part OneNeuron 5. Neuron and Its PartsNeuron: Individual nerve cell; 100 billion in brain- Dendrites: Receive messages from other neurons;have thousands of branches- Soma: Cell body; metabolic center of neuron; containsgenetic material- Axon: Carries information away from the cell body;longest part of neuron- Axon Terminals: Branches that link the dendrites andsoma of other neurons- Synaptic Gap: Space between the end of the axon ofone neuron and the dendrites of an adjacent neuron 6. Picture of a Neuron 7. The Nerve Impulse Resting Potential: Electrical charge of an inactive neuron Threshold: Trigger point for a neurons firing Action Potential: Nerve impulse 8. Resting PotentialResting Potential: Tiny charge between inside & outside ofneuron Created by electrically charged particles (ions)- Some concentrated outside the cell (sodium andchloride ions)- Some concentrated inside the cell (Potassium ions) How is the charge maintained?- Sodium-potassium pump- Selectively permeable cell membrane 9. Action PotentialAction potential: Change in potential, primarily becauseof messages from other neurons Excitatory messages: Cell loses the negative charge;Depolarization Inhibitory messages: Cell becomes more negativelycharged; Hyperpolarization 10. Resting vs. Action Potential 11. Graphic: Action Potential 12. Graphic: Action Potential 13. Graphic: Synaptic Gap 14. NeurotransmittersNeurotransmitters: Chemicals that alter activity inneurons; brain chemicals. Messages from one neuron toanother pass over the synapse, the microscopic gapbetween neuronsReceptor Site: Areas on the surface of neurons and othercells that are sensitive to neurotransmittersAntagonist: drug that decreases activity of a neurotrans-mitter 15. Some Neurotransmitters Acetylcholine: involved in learning, memory, and musclecontractions. Botulism toxin prevents release of acetylcholine,resulting in paralysis Dopamine: involved in arousal, mood, and movement. InParkinsons, receptors in brain fail to react to dopamine, leading totremors, rigidity and problems initiating movement Serotonin and Norepinephrine: involved in arousal and mood.Cocaine blocks re-uptake of both neurotransmitters, resulting in high GABA (gamma-aminobutyric acid): main inhibitory neurotrans-mitter;lowers arousal and anxiety Endorphins: lower pain perception. Morphine and heroin bind toendorphin receptors, increasing endorphin activity. 16. Nerves and Neurons Nerves: Large bundles of neurons Myelin: Fatty layer of tissue that coats axons Multiple Sclerosis (MS) occurs when myelin layer isdestroyed; numbness, weakness, and paralysis occur 17. A Little ExerciseDemonstration of the speedof a neural impulse. 18. An Organizational PauseOrganization ofthe CNS 19. Major Sections ofthe Nervous System Central Nervous System (CNS): Brain and spinal cord Peripheral Nervous System: All parts of the nervoussystem outside of the brain and spinal cord- Autonomic System: Serves internal organs and glands;controls automatic functions such as heart rate and bloodpressure- Somatic System: Links spinal cord with skeletalmuscles and sense organs; controls voluntary behavior 20. Organization of Nervous System 21. Graphic: Nervous System 22. Part 2The Peripheral Nervous SystemSee in class! The Autonomic Nervous System The Somatic Nervous System 23. Divisions of Autonomic System Sympathetic: Arouses body; emergency system Parasympathetic: Quiets body; most active after anemotional event 24. Functions ofAutonomic Nervous System 25. Three Components of Emotion Physical component: state of physiologicalarousal triggered by autonomic nervous system Behavioral component: outward expression of theemotion, including facial expression & behavior Cognitive component: appraisal of the situation todetermine which emotion we are experiencing andwhy 26. James-Lange Theory of Emotion 27. Cannon-Bard Theory of Emotion 28. Schachter-Singer Theory 29. Comparison ofThree Theories of Emotion 30. Somatic Nervous System Motor Nervous System: transfers messages from CNSto control function of voluntary muscles Sensory Nervous System: transfers messages fromsensory organs to CNS; brings information from outsidethe body to the brain to be processed 31. Structures in Somatic System Sensory neuron: neuron that transmits informationfrom sensory organ to CNS Motor neuron: neuron that transmits information fromCNS to voluntary muscle Connector neuron: neuron in spinal cord connectingsensory and motor neurons to form reflex arc. Reflex: An innate, automatic motor response to aspecific sensory stimulus 32. Graphic: Somatic Nervous System 33. Motor & Somatosensory Areasin Cerebral Cortex 34. Motor Homunculushomunculus =a diminutive humanbeing 35. Somesthetic Homunculus 36. A Little ExerciseA demonstration of the somatosensorysystem, using toothpicks and little rulers. 37. Part 3The Central Nervous SystemSee in class! The Spinal Cord The Brain- The Central Core- The Limbic System- The Cerebral Cortex 38. The Spinal Cord Spinal Nerves: 31 of them; carry sensory and motormessages to and from the spinal cord Cranial Nerves: 12 pairs that leave the brain directly;also work to communicate messages Spinal cord functions to connect peripheral nervoussystem to the brain 39. The Central Core(aka the old brain) Medulla: Connects brain with the spinal cord and controls vitallife functions such as heart rate and breathing Cerebellum: Regulates posture, muscle tone, muscularcoordination, and procedural learning Reticular formation: Associated with levels of arousal andconsciousness, as well as some reflexes (breathing, coughing,sneezing, vomiting) Thalamus: serves as a relay station for incoming sensoryInformation Basal ganglia: involved in physical movement 40. Graphic: Central Core 41. The Limbic SystemAt the top border (limbus in Latin) of the brain stem.Hypothalamus: controls pituitary gland (directing activity ofendocrine system) and autonomic nervous system; involved inbasic drives (eating, drinking, sex) Hippocampus: involved in formation of memories Amygdala: involved in regulating emotional experiences,particularly initial emotional responses 42. Graphic: Limbic System 43. Neocortex Cerebral Cortex: Outer layer of the cerebrum Cerebrum: Two large hemispheres that cover upper partof the brain Corticalization: Increase in size and wrinkling of thecortex Cerebral Hemispheres: Right and left halves of thecerebrum Corpus Callosum: Bundle of fibers connecting cerebralhemispheres 44. Graphic: Relative Size 45. Graphic: Corpus Callosum 46. Left & Right Hemispheres 47. Left Brain/Right Brain About 95 percent of our left brain is used for language Left hemisphere better at math, judging time and rhythm,and coordinating order of complex movements- Processes information sequentially Right hemisphere good at perceptual skills, and atexpressing and detecting others emotions- Processes information simultaneously 48. Graphic: Left vs. Right 49. Lobes of the Neocortex Occipital Lobe: Back of brain; vision center Parietal Lobe: Just above occipital; bodilysensations such as touch, pain, and temperature(somatosensory area) Temporal Lobe: Each side of the brain; auditory andlanguage centers Frontal Lobe: Movement, sense of smell, highermental functions; contains motor cortex; controls motormovement 50. Graphic: Lobes