Nervous System.ppt
- 1. Module 4 Incredible Nervous System
- 2. GENES & EVOLUTION • Genetic information – brain and body developed according to complex chemical instructions that were written in a human cell no larger than a grain of sand
- 3. GENES & EVOLUTION (CONT.) • 1. Fertilization – human life has its beginnings when a father’s sperm, which contains 23 chromosomes, penetrates a mother’s egg, which contains 23 chromosomes
- 4. GENES & EVOLUTION (CONT.)
- 5. GENES & EVOLUTION (CONT.) • 2. Zygote – the largest human cell, about the size of a grain of sand – a zygote is a cell that results when an egg is fertilized – a zygote contains 46 chromosomes arranged in 23 pairs
- 6. GENES & EVOLUTION (CONT.) • 3. Chromosomes – a short, rodlike, microscopic structure that contains a tightly coiled strand of the chemical DNA, which is an abbreviation for deoxyribonucleic acid
- 7. GENES & EVOLUTION (CONT.)
- 8. GENES & EVOLUTION (CONT.) • 4. Chemical alphabet – each chromosome contains a long, coiled strand of DNA, which resembles a ladder that has been twisted over and over upon itself – each rung of the DNA ladder is made up of four chemicals – the order in which the four different chemicals combine to form rungs creates a microscopic alphabet
- 9. GENES & EVOLUTION (CONT.)
- 10. GENES & EVOLUTION (CONT.) • 5. Genes and proteins – Gene • a specific segment on the long strand of DNA that contains instructions for making proteins – Proteins • chemical building blocks from which all the parts of the brain and body are constructed
- 11. GENES & EVOLUTION (CONT.) • 6. Genome – The Human Genome Project – began in 1995 and cost over $2.7 billion – reached its first goal in 2003 of mapping all the human genes – researchers found only about 30,000 human genes instead of the estimated 100,000 – It is a blue print of genes
- 12. GENES & EVOLUTION (CONT.) • 7. Genetic factors – researchers are discovering how genetic factors interact with the environment to result in the development of mental retardation, emotional and personality traits, mental disorders, and various cognitive abilities
- 13. EVOLUTION OF THE HUMAN BRAIN • Evolution of the human brain – 1859 Charles Darwin published the Origin of Species • Theory of Evolution – says that different species arose from a common ancestor and that those species that survived were best adapted to meet the demands of their environment – humans and chimpanzees share at least 98% of their DNA
- 14. EVOLUTION OF THE HUMAN BRAIN
- 15. EVOLUTION OF THE HUMAN BRAIN • Australopithecus (Lucy) – 3-4 million years ago – brain weight 500 grams (size of a chimp) • no tools, no language, no fire • Homo erectus – 1.5 million years ago – brain weight 1,000 grams • Stone tools (possibly language) • Homo sapiens – 400,000 years ago – brain weight 1350 grams or 3 pounds
- 16. STUDYING THE LIVING BRAIN • Brain scans – techniques that can look through the thick skull and picture the brain with astonishing clarity yet cause no damage to the extremely delicate brain cells – researchers are mapping a variety of cognitive functions: – attention, language, memory, motor skills
- 17. STUDYING THE LIVING BRAIN (CONT.) • MRI – magnetic resonance imagery – involves passing nonharmful radio frequencies through the brain • fMRI – functional magnetic resonance imaging – measures the activity of specific neurons that are functioning during cognitive tasks, such as thinking, listening
- 18. STUDYING THE LIVING BRAIN (CONT.)
- 19. STUDYING THE LIVING BRAIN (CONT.) • Brain scans and Cognitive Neuroscience – PET scan – positron emission tomography – involves injecting a slightly radioactive solution into the blood and then measuring the amount of radiation absorbed by brain cells called neurons
- 20. STUDYING THE LIVING BRAIN (CONT.) • Brain scans and Cognitive Neuroscience – Neuroimaging • PET and fMRI scans are used to identify and map the living brain’s neural activity as a person performs complex behavioral and cognitive tasks, such as: – seeing – moving – thinking – speaking – empathizing – trusting – even reacting to TV violence
- 21. STUDYING THE LIVING BRAIN (CONT.)
- 22. STUDYING THE LIVING BRAIN (CONT.) • Tools versus Animals – naming animals – naming tools
- 23. STUDYING THE LIVING BRAIN (CONT.)
- 24. STUDYING THE LIVING BRAIN (CONT.)
- 25. ORGANİSATİON OF THE BRAİN Machine Translated by Google
- 26. ORGANIZATION OF THE BRAIN (CONT.)
- 27. ORGANIZATION OF THE BRAIN • Divisions of the Nervous System • Major divisions of the nervous system – central nervous system - CNS – peripheral nervous system - PNS
- 28. ORGANIZATION OF THE BRAIN (CONT.) • Central nervous system - CNS – made up of the brain and spinal cord
- 29. ORGANIZATION OF THE BRAIN (CONT.) • Peripheral nervous system - PNS – includes all the nerves that extend from the spinal cord and carry messages to and from various muscles, glands, and sense organs located throughout the body • Subdivisions of the PNS – somatic nervous system – autonomic nervous system - ANS – sympathetic division – parasympathetic division
- 30. ORGANIZATION OF THE BRAIN (CONT.) • Somatic nervous system – network of nerves that connect either to sensory receptors or to muscles that you can move voluntarily, such as muscles in your limbs, back, neck, and chest – nerves contain two kinds of fibers • Afferent – sensory fibers; carry information to the brain • Efferent – motor fibers; carry information from brain or spinal cord to the muscles
- 31. ORGANIZATION OF THE BRAIN (CONT.) • Autonomic nervous system - ANS – regulates heart rate, breathing, blood pressure, digestion, hormone secretion, and other functions • Sympathetic division – triggered by threatening or challenging physical or psychological stimuli, increases physiological arousal and prepares the body for action (epinephrine) • Parasympathetic division – returns the body to a calmer, relaxed state and is involved in digestion (norepinephrine) = Homeostasis
- 32. LIMBIC SYSTEM: OLD BRAIN (CONT.)
- 33. ORGANIZATION OF THE BRAIN (CONT.)
- 34. ORGANIZATION OF THE BRAIN (CONT.) • Forebrain – largest part of the brain – has right and left sides called hemispheres – hemispheres are responsible for a number of functions, including learning and memory, speaking and language, emotional responses, experiencing sensations, initiating voluntary movements, planning, and making decisions
- 35. ORGANIZATION OF THE BRAIN (CONT.) • Midbrain – has a reward or pleasure center, which stimulated by food, sex, money, music, looking at attractive faces, and some drugs (cocaine) – has areas for visual and auditory reflexes – contains the reticular formation, which arouses the forebrain so that it is ready to process information from the senses
- 36. ORGANIZATION OF THE BRAIN (CONT.) • Hindbrain – Has three distinct structures: • Pons • Medulla • Cerebellum
- 37. ORGANIZATION OF THE BRAIN (CONT.) • Pons – functions as a bridge to interconnect messages between the spinal cord and brain • Medulla – located on top of the spinal cord – includes a group of cells that control vital reflexes, such as respiration, heart rate, and blood pressure • Cerebellum – located in the very back and underneath the brain – involved in coordinating motor movements but not in initiating voluntary movements
- 38. CONTROL CENTERS: FOUR LOBES • Wrinkled cortex – a thin layer of cells that essentially covers the entire surface of the forebrain
- 39. CONTROL CENTERS: FOUR LOBES (CONT.)
- 40. CONTROL CENTERS: FOUR LOBES (CONT.) • Four lobes – Frontal lobe – Parietal lobe – Occipital lobe – Temporal lobe
- 41. CONTROL CENTERS: FOUR LOBES (CONT.)
- 42. CONTROL CENTERS: FOUR LOBES (CONT.) • Frontal lobe – involved with personality, emotions, and motor behaviors, decision making • Parietal lobe – involved with perception and sensory experiences • Occipital lobe – involved with visual processing • Temporal lobe – involved with hearing and speaking
- 43. CONTROL CENTERS: FOUR LOBES (CONT.) • Frontal lobe: functions – Phineas Gage • http://www.youtube.com/watch?v=MvpIRN9D4D4 • Frontal Lobotomy – A surgical procedure in which about one-third of the front part of the frontal lobe was cut away from the rest of the brain – 18,000 were performed during the 1940s and 1950s
- 44. CONTROL CENTERS: FOUR LOBES (CONT.)
- 45. CONTROL CENTERS: FOUR LOBES (CONT.)
- 46. CONTROL CENTERS: FOUR LOBES (CONT.) • Frontal lobe: functions – motor cortex – narrow strip of cortex that is located on the back edge of the frontal lobe and extends down its side – involved in the initiation of all voluntary movements – right side controls left – left side controls right – organization and function of motor cortex
- 47. CONTROL CENTERS: FOUR LOBES (CONT.)
- 48. CONTROL CENTERS: FOUR LOBES (CONT.) • Other functions of frontal lobe – much knowledge of other frontal lobe functions comes from individuals who had damage to that area – frontal lobes are involved in paying attention, organizing, planning, deciding, and carrying out various cognitive tasks and social-emotional behaviors – executive function
- 49. CONTROL CENTERS: FOUR LOBES (CONT.) • Parietal lobe: function – location of somatosensory cortex – narrow strip of cortex that is located on the front edge of the parietal lobe and extends down its side
- 50. CONTROL CENTERS: FOUR LOBES (CONT.)
- 51. CONTROL CENTERS: FOUR LOBES (CONT.)
- 52. CONTROL CENTERS: FOUR LOBES (CONT.) • Other functions of parietal lobe – involved in several cognitive functions, including recognizing objects, remembering items, and perceiving and analyzing objects in space
- 53. CONTROL CENTERS: FOUR LOBES (CONT.) • Temporal lobe: functions – primary auditory cortex – located on top edge of each temporal lobe, receives electrical signals from receptors in the ears and transforms these signals into meaningful sound sensations, such as vowels and consonants
- 54. CONTROL CENTERS: FOUR LOBES (CONT.)
- 55. CONTROL CENTERS: FOUR LOBES (CONT.) • Temporal lobe: functions – auditory association area – located directly below the primary auditory cortex – transforms basic sensory information, such as noises or sounds, into recognizable auditory information, such as words or music
- 56. CONTROL CENTERS: FOUR LOBES (CONT.) • Temporal lobe: functions – Broca’s area - frontal lobe • located in left frontal lobe • necessary for combining sounds into words and arranging words into meaningful sentences • damage: Broca’s aphasia – person cannot speak in fluent sentences but can understand written and spoken words
- 57. CONTROL CENTERS: FOUR LOBES (CONT.) – Wernicke’s area • located in the left temporal lobe • necessary for speaking in coherent sentences and for understanding speech • Damage: Wernicke’s aphasia – difficulty in understanding spoken or written words and a difficulty in putting words into meaningful sentences
- 58. CONTROL CENTERS: FOUR LOBES (CONT.)
- 59. CONTROL CENTERS: FOUR LOBES (CONT.) • Occipital lobe: functions – vision – primary visual cortex – located at the very back of the occipital lobe – receives electrical signals from receptors in the eyes and transforms these signals into meaningless basic visual sensations, such as lights, lines, shadows, colors, and textures
- 60. CONTROL CENTERS: FOUR LOBES (CONT.)
- 61. CONTROL CENTERS: FOUR LOBES (CONT.) • Occipital lobe: functions – visual association area – transforms basic sensations, such as lights, lines, colors, and textures, into complete, meaningful visual perceptions, such as persons, objects, or animals
- 62. LIMBIC SYSTEM: OLD BRAIN • group of about half a dozen interconnected structures that make up the core of the forebrain • involved with regulating many motivational behaviors such as obtaining food, drink, and sex • organizing emotional behaviors such as fear, anger, and aggression; storing memories • Structures and functions – Hypothalamus – Amygdala – Thalamus – Hippocampus
- 63. LIMBIC SYSTEM: OLD BRAIN (CONT.)
- 64. LIMBIC SYSTEM: OLD BRAIN (CONT.) • Hypothalamus – regulates many motivational behaviors, including eating, drinking, and sexual responses; emotional behaviors such as arousing the body when fighting or fleeing, and secretion of hormones, such as occurs at puberty • Amygdala – located in the tip of the temporal lobe – receives input from all the senses – evaluates the emotional significance of stimuli and facial expressions, especially those involving fear, distress, or threat
- 65. LIMBIC SYSTEM: OLD BRAIN (CONT.) • Thalamus – gathers and processes information from the senses – involved in receiving sensory information, doing some initial processing, and then relaying the sensory information to areas of the cortex • Hippocampus – curved structure inside the temporal lobe – Involved in saving many kinds of fleeting memories by putting them into permanent storage in various parts of the brain