Module 4

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Module 4

• Incredible Nervous System
• Stillwater High School
• Psych 1, Fall 2010

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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
• Fertilization
• Zygote
• Chromosomes
• Chemical alphabet
• Genes and proteins
• Genome
• Genetic factors

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GENES EVOLUTION (CONT.)

• Fertilization
• human life has its beginnings when a fathers
  sperm, which contains 23 chromosomes, penetrates
  a mothers egg, which contains 23 chromosomes

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p68 SPERM EGG ZYGOTE
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GENES EVOLUTION (CONT.)

• 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

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GENES EVOLUTION (CONT.)

• Chromosomes
• a short, rodlike, microscopic structure that
  contains a tightly coiled strand of the chemical
  DNA, which is an abbreviation for
  deoxyribonucleic acid

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GENES EVOLUTION (CONT.)

• Chemical alphabet
• each chromosome contains a long, coiled strand of
  DNA, which resembles a ladder that has been
  twisted over an 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

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p68 DNA
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GENES EVOLUTION (CONT.)

• 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

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p68 CHROMOSOME
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GENES EVOLUTION (CONT.)

• 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

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GENES EVOLUTION (CONT.)

• 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
• Fragile X syndrome
• an inherited developmental disability, is due to
  a defect in the X chromosome

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GENES EVOLUTION (CONT.)

• 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

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p69 SKULL SIZE
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STUDYING THE LIVING BRAIN

• Brain scans
• techniques that can look through the thick skull
  and picture the brain with astonishingly clarity
  yet cause no damage to the extremely delicate
  brain cells
• MRI and fMRI

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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

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p70 MRI
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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

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p71 PET
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STUDYING THE LIVING BRAIN (CONT.)

• Tools versus Animals
• naming animals
• naming tools

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p71 THINK OF ANIMALS BRAIN
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p71 THINKING OF TOOLS BRAIN
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ORGANIZATION OF THE BRAIN

• Divisions of the Nervous System
• Major divisions of the nervous system
• central nervous system - CNS
• peripheral nervous system - PNS

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ORGANIZATION OF THE BRAIN (CONT.)

• Central nervous system - CNS
• made up of the brain and spinal cord

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p72 CNS
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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

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p72 PNS
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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

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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
• Parasympathetic division
• returns the body to a calmer, relaxed state and
  is involved in digestion

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ORGANIZATION OF THE BRAIN (CONT.)

• Major Parts of the Brain
• Forebrain
• Midbrain
• Hindbrain
• pons
• medulla
• cerebellum

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p73 SIDE VIEW OF BRAIN
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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

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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

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ORGANIZATION OF THE BRAIN (CONT.)

• Hindbrain
• Has three distinct structures
• Pons
• Medulla
• cerebellum

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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

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CONTROL CENTERS FOUR LOBES

• Wrinkled cortex
• a thin layer of cells that essentially covers the
  entire surface of the forebrain

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CONTROL CENTERS FOUR LOBES (CONT.)

• Four lobes
• Frontal lobe
• Parietal lobe
• Occipital lobe
• Temporal lobe

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p74 FOUR LOBES
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CONTROL CENTERS FOUR LOBES (CONT.)

• Frontal lobe
• involved with personality, emotions, and motor
  behaviors
• Parietal lobe
• involved with perception and sensory experiences
• Occipital lobe
• involved with visual processing
• Temporal lobe
• involved with hearing and speaking

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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

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p76 MOTOR CORTEX
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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
• Phineas Gage

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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

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p77 SENSORY HOMUNCULUS
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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

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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

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p78 TEMPORAL LOBE
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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

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CONTROL CENTERS FOUR LOBES (CONT.)

• Temporal lobe functions
• Brocas area - frontal lobe
• located in left frontal lobe
• necessary for combining sounds into words and
  arranging words into meaningful sentences
• Wernickes area
• located in the left temporal lobe
• necessary for speaking in coherent sentences and
  for understanding speech

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p78 BROCAS WERNIKES
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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

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p79 OCCIPITAL LOBE
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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

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LIMBIC SYSTEM OLD BRAIN

• Structures and functions
• Hypothalamus
• Amygdala
• Thalamus
• Hippocampus

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p80 LIMBIC SYSTEM
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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

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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

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LIMBIC SYSTEM OLD BRAIN (CONT.)

• Autonomic nervous system
• Sympathetic
• Parasympathetic

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p81 SYMPATHETIC PARASYMPATHETIC
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LIMBIC SYSTEM OLD BRAIN (CONT.)

• Autonomic nervous system
• Sympathetic
• triggered by threatening or challenging physical
  or psychological stimuli
• Physiological responses
• increased heart rate, increased blood pressure,
  and dilated pupils
• fight or flight

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LIMBIC SYSTEM OLD BRAIN (CONT.)

• Autonomic nervous system
• Parasympathetic
• decreases physiological arousal
• returns the body to a calmer, more relaxed state
• stimulates digestion during eating
• Physiological responses
• decreases heart rate
• lowers blood pressure
• stimulate digestion
• body returns to more relaxed state.

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LIMBIC SYSTEM OLD BRAIN (CONT.)

• Autonomic nervous system
• Homeostasis
• sympathetic and parasympathetic systems work
  together to keep the bodys level of arousal in
  balance for optimum functioning

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ENOCRINE SYSTEM

• Endocrine System
• Made up of numerous glands that are located
  throughout the body. Glands secrete various
  chemicals called hormones.
• Pituitary
• Pancreas
• Thyroid
• Adrenal glands
• Gonads

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p82 ENDOCRINE SYSTEM
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ENOCRINE SYSTEM (CONT.)

• Pituitary gland
• hangs below the hypothalamus
• divided into anterior and posterior
• Posterior
• rear portion
• regulates water and salt balance
• Anterior
• front portion
• regulates growth through secretion of growth
  hormone
• produces hormones that control the adrenal
  cortex, pancreas, thyroid, and pancreas

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ENOCRINE SYSTEM (CONT.)

• Pancreas
• regulates the level of sugar in the bloodstream
  by secreting insulin
• Thyroid
• located in the neck
• regulates metabolism through secretion of hormones

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ENOCRINE SYSTEM (CONT.)

• Adrenal glands
• adrenal cortex (outside part)
• secretes hormones that regulate sugar and salt
  balance
• adrenal medulla (inside part)
• secretes two hormones that arouse the body to
  deal with stress and emergencies
• epinephrine (adrenaline)
• norepinephrine (noradrenaline)

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ENOCRINE SYSTEM (CONT.)

• Gonads
• Females
• ovaries produce hormones that regulate sexual
  development, ovulation, and growth of sex organs
• Males
• testes produce hormones that regulate sexual
  development, production of sperm, and growth of
  sex organs