The document discusses the organization and functions of the human brain and nervous system. It describes how genetic information contained in DNA directs brain development and evolution. It then covers the major divisions and structures of the brain and nervous system, including the four lobes of the cerebral cortex and their functions. Finally, it discusses the limbic system and its role in regulating emotions and memory.

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