1. Chapter 2 Brain and Behavior

2. Neuron and Its Parts Neuron: Individual nerve cell; 100 billion in brain

3. Neuron’s Parts –Soma: Cell body; body of the neuron. Receives messages and sends messages down axon –Axon: Fiber that carries information away from the cell body of a neuron –Axon terminals: Branches that link the dendrites and somas of other neurons –Dendrites: Receive messages from other neurons

4. Fig. 2-1, p. 49

5. Fig. 2-4, p. 51

6. Video: Main Parts of the Neuron

7. The Nerve Impulse Resting potential: Electrical charge of an inactive neuron Threshold: Trigger point for a neuron’s firing Action Potential: Nerve impulse

8. Fig. 2-2, p. 50

9. More on Nerves Ion channels: Tiny openings through the axon membrane Negative after-potential: A drop in electrical charge below the resting potential Synapse: Microscopic space between two neurons over which messages pass

10. Saltatory Conduction Process by which nerve impulses conducted down the axons of neurons coated with myelin jump from gap to gap in the myelin layer Myelin: A fatty layer coating some axons

11. Fig. 2-5, p. 51

12. Fig. 2-3, p. 50

13. Video: Action Potential

14. Video: Synaptic Transmission

15. Neurotransmitters Chemicals that alter activity in neurons; brain chemicals Receptor site: Area on the surface of neurons and other cells that is sensitive to neurotransmitters or hormones

16. Types of Neurotransmitters –Acetylcholine: Activates muscles –Dopamine: Muscle control –Serotonin: Mood and appetite control

17. Neural Regulators Neuropeptides: Regulate activity of other neurons –Enkephalins: Relieve pain and stress; similar to endorphins –Endorphins: Released by pituitary gland; also help to relieve pain Placebos raise endorphin levels

18. Fig. 2-6, p. 52

19. Neuroplasticity Capacity of our brains to change in response to experience

20. Neural Networks Central nervous system (CNS): Brain and spinal cord Peripheral nervous system: All parts of the nervous system outside of the brain and spinal cord

21. Nerves and Neurons (cont) Neurilemma: Thin layer of cells wrapped around axons outside brain and spinal cord; forms a tunnel that damaged fibers follow as they repair themselves

22. Fig. 2-7, p. 53

23. Two Divisions of the Peripheral Nervous System Somatic System: Carries messages to and from skeletal muscles and sense organs; controls voluntary behavior Autonomic System: Serves internal organs and glands; controls automatic functions such as heart rate and digestion pressure

24. Two Divisions of the Autonomic Nervous System Sympathetic: Arouses body; emergency system Parasympathetic: Quiets body; most active after an emotional event

25. Fig. 2-8, p. 54

26. The Spinal Cord Spinal Nerves: 31 of them; carry sensory and motor messages to and from the spinal cord Cranial Nerves: 12 pairs that leave the brain directly; also work to communicate messages

27. The Spinal Cord and Behavior Reflex Arc: Simplest behavior; occurs when a stimulus provokes an automatic response Sensory Neuron: Nerve cell that carries messages from the senses toward the CNS Connector Neuron: Nerve cell that links two others Motor Neuron: Cell that carries commands from the CNS to muscles and glands

28. Fig. 2-9, p. 54

29. Effector Cells Cells capable of producing a response

30. Neurogenesis The production of new brain cells

31. Brain Imaging Techniques Computed Tomographic Scanning (CT): Computer-enhanced X-ray of the brain or body Magnetic Resonance Imaging (MRI): Uses a strong magnetic field, not an X-ray, to produce an image of the body’s interior

32. Localization of Function Research strategy of linking specific structures in the brain with specific psychological or behavioral functions

33. Researching the Brain Ablation: Surgical removal of parts of the brain Deep lesioning: A thin wire electrode is lowered into a specific area inside the brain; electrical current is then used to destroy a small amount of brain tissue Electrical stimulation of the brain (ESB): When an electrode is used to activate target areas in the brain

34. Electroencephalograph (EEG) A device that detects, amplifies, and records electrical activity in the brain

35. More Brain Imaging Techniques Functional MRI: MRI that makes brain activity visible Positron emission tomography (PET): Computer-generated color image of brain activity, based on glucose consumption in the brain

36. Fig. 2-12, p. 58

37. Fig. 2-11, p. 57

38. Fig. 2-14, p. 59

39. Fig. 2-10, p. 57

40. Fig. 2-15, p. 59

41. Cerebral Cortex Definition: Outer layer of the brain; contains 70% of neurons in CNS Cerebrum: Two large hemispheres that cover upper part of the brain Corticalization: Increase in size and wrinkling of the cortex Cerebral hemispheres: Right and left halves of the cortex

42. Corpus Callosum Bundle of fibers connecting cerebral hemispheres

43. Neurological Soft Signs Subtle behavioral signs of brain dysfunction –Clumsiness –Awkward gait –Poor hand-eye coordination –Other perceptual and motor problems

44. Fig. 2-17, p. 60

45. Split Brains Corpus callosum is cut; done to control severe epilepsy (seizure disorder) Result: The person now has two brains in one body This operation is rare and is often used as a last resort

46. Fig. 2-20, p. 62

47. Fig. 2-16, p. 60

48. Right Brain/Left Brain Humans use 95 percent of our left brain for language –Speaking, writing, understanding

49. The Left Hemisphere Left hemisphere better at math, judging time and rhythm, and coordinating order of complex movements –Processes information sequentially

50. The Right Hemisphere Right hemisphere good at perceptual skills, and at expressing and detecting other’s emotions –Good at recognizing patterns, faces, and melodies –Processes information simultaneously and holistically

51. Frontal Lobe Movement, sense of smell, higher mental functions –Contains primary motor cortex; controls motor movement Mirror neurons: Contained in motor cortex; become active when motor action is carried out and when another organism is observed carrying out the same action

52. Video: Frontal Lobe

53. p. 65

54. Association Cortex All areas of cerebral cortex that are not primarily sensory or motor in function

55. Aphasia Language disturbance resulting from brain damage

56. Broca’s Area Related to grammar and pronunciation –If damaged, person knows what s/he wants to say but can’t say the words

57. Prefrontal Cortex Front of frontal lobes; involved in sense of self, reasoning, and planning

58. Parietal Lobe Just above occipital; bodily sensations such as touch, pain, and temperature (somatosensory area) Primary somatosensory cortex: Receiving area for bodily sensations

59. Temporal Lobe Each side of the brain; auditory center and, for 95 percent of humans, language centers Primary auditory area: Auditory information is first registered here

60. Wernicke’s Area Related to language comprehension; in left temporal lobe –If damaged, person has problems with meanings of words, NOT pronunciation

61. Fig. 2-24, p. 66

62. Occipital Lobe Back of brain; vision center Primary visual area: Part of occipital lobe that first receives input from the eyes

63. Fig. 2-19, p. 61

64. Fig. 2-22, p. 63

65. Fig. 2-23, p. 64

66. Agnosias Visual Agnosia: Inability to identify seen objects Facial Agnosia: Inability to perceive familiar faces

67. Fig. 2-18, p. 61

68. Subcortex All brain structures immediately below cerebral cortex

69. Hindbrain (Brainstem) Consists mainly of medulla and cerebellum Also includes pons and reticular formation

70. Video: Hindbrain

71. Medulla Controls vital life functions such as heart rate, swallowing, and breathing

72. Pons (Bridge) Pons (Bridge): Acts as a bridge between medulla and other structures –Influences sleep and arousal

73. Cerebellum Cerebellum: Located at base of brain –Regulates posture, muscle tone, and muscular coordination

74. Reticular Formation (RF) Inside medulla and brainstem –Associated with alertness, attention, and some reflexes (breathing, coughing, sneezing, vomiting)

75. Reticular Activating System (RAS) Part of RF that keeps it active and alert –RAS acts like the brain’s alarm clock –Activates and arouses cerebral cortex

76. Video: Brainstem

77. Forebrain Structures are part of the limbic system, the system within the forebrain closely linked to emotional response and motivating behavior

78. Video: Limbic System

79. Thalamus Relays sensory information on the way to the cortex; switchboard

80. Hypothalamus Regulates emotional behaviors and motives (e.g., sex, hunger, rage, hormone release)

81. Amygdala Associated with fear responses

82. Hippocampus Associated with storing permanent memories; helps us navigate through space

83. Endocrine System Glands that pour chemicals (hormones) directly into the bloodstream or lymph system

84. Pituitary Gland Regulates growth via growth hormone Its hormones influence other endocrine glands

85. Pituitary Problems Too little growth hormone means person will be smaller than average –Hypopituitary dwarfism: As adults, perfectly proportioned but tiny Treatable by using human or synthetic growth hormone; will add a few inches

86. Fig. 2-25, p. 68

87. Fig. 2-26, p. 69

88. Pituitary Problems (cont) Too much growth hormone leads to gigantism (excessive body growth) Acromegaly: Enlargement of arms, hands, feet, and facial bones; due to too much growth hormone secreted late in growth period –Andre the Giant Pituitary also governs functioning of other glands, especially thyroid, adrenals, and gonads

89. The Pineal Gland Regulates body rhythms and sleep cycles –Releases the hormone melatonin, which responds to daily variations in light

90. The Thyroid Gland In neck; regulates metabolism –Hyperthyroidism: Overactive thyroid; person tends to be thin, tense, excitable, nervous –Hypothyroidism: Underactive thyroid; person tends to be inactive, sleepy, slow, obese, and depressed

91. The Adrenal Glands Adrenals: Arouse body, regulate salt balance, adjust body to stress, regulate sexual functioning; located on top of kidneys –Releases epinephrine and norepinephrine (also known as adrenaline and noradrenaline)

92. Adrenal Hormones Epinephrine arouses body; is associated with fear Norepinephrine arouses body; is linked with anger

93. The Adrenal Glands (cont) Adrenal medulla: Inner core of adrenals; source of epinephrine and norepinephrine Adrenal cortex: Produces hormones known as corticoids –Regulate salt balance, among other functions

94. Adrenal Malfunctions Oversecretion of adrenal sex hormones can cause virilism: exaggerated male characteristics (bearded woman) –May also cause premature puberty if oversecretion occurs early in life

95. Fig. 2-27, p. 70

96. Fig. 2-29, p. 74

97. Handedness Preference for right or left hand in most activities Dominant Hemisphere: Term usually applied to the side of the human brain that produces language Lateralization: Specialization in abilities of brain hemispheres