Nervous System

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Nervous System

• Basic Structure
• 1. Central Nervous System (CNS)
• - Brain
• - Spinal Cord nerves that run up and down the
  length of the back transmit most messages
  between the body and the brain

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Nervous System

• Basic Structure
• 2. Peripheral Nervous System (PNS)
• Smaller branches of nerves that reach other parts
  of the body
• Take information from organs to CNS and back to
  the organs

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Nervous System

• Neurons
• Long, thin cells of nerve tissue along which
  messages travel to and from the brain
• Chemical, electrical signals travel down neurons
  at full speed when stimulated

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Nervous System

• Four Parts of Neurons
• Cell Body contains nucleus and produces energy
  to fuel neuron activity

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Nervous System

• Four Parts of Neurons
• Dendrites short, thin fibers that stick out
  from the cell body
• - receive impulses (messages) from other neurons
  and sends them to the cell body

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Nervous System

• Four Parts of Neurons
• 3. Axon long fiber that carries impulses from
  the cell body toward dendrites of the next neuron
• - insulated and protected by a myelin sheath

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Nervous System

• Four Parts of Neurons
• 4. Axon terminals small fibers that branch out
  at the end of an axon

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Nervous System

• Synapse
• Gap between individual nerve cells

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Nervous System

• Neurotransmitters
• Chemicals released by neurons which
• determine the rate at which other
• neurons fire

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Nervous System

• Neurotransmitters (examples)
• Norepinephrine memory and learning
• Endorphin inhibits pain
• Dopamine learning, emotional arousal and
  movement

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Nervous System

• Voluntary and Involuntary Activities
• Somatic Nervous System part of the peripheral
  nervous system that controls voluntary activities
  (lifting a hand, turning a page, etc.)

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Nervous System

• Voluntary and Involuntary Activities
• Autonomic Nervous System (ANS) part of the
  peripheral nervous system that controls internal,
  biological functions (heartbeat, digestion, etc.)

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The Brain Group Activity

• In groups of 3-5, take a part of the brain (pick
  a card)
• Read Chapter 6, Section 2 about the part
• Create an annotated illustration to present to
  the class (I have paper)
• Include the function of the part and how it
  interacts with other parts of the body
• Can use drawings, signs, and props to aid the
  presentation

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Parts of the Brain

• Hindbrain
• Cerebellum posture, balance, voluntary
  movements
• Medulla breathing, heart rate, reflexes
• Pons bridge between spinal cord and brain and
  produces chemicals needed for sleep

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Parts of the Brain

• Midbrain
• Integrates sensory information and relays it
  upward
• Along with the medulla and pons it composes most
  of the brain stem
• RAS (reticular activating system) alerts brain
  to incoming signals and involved in the
  sleep/wake cycle

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Parts of the Brain

• Forebrain
• Thalmus integrates sensory input (except for
  smell)
• Hypothalmus controls hunger, thirst, and sexual
  behavior, and reactions to changes in temperature

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Parts of the Brain

• Forebrain
• Cerebral Cortex Cerebrum gives ability to
  learn and store information and have future
  thoughts
• Limbic System regulates emotions and
  motivations (hypothalmus, amygdala, thalamus,
  hippocampus)

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Parts of the Brain

• Cerebrum is in two halves (hemispheres)
• Hemispheres connected with fibers called the
  corpus callosum
• Each hemisphere has lobes
• Occipital lobe vision
• Parietal lobe senses from all of body
• Temporal lobe hearing, memory, emotion,
  speaking
• Frontal lobe organization, planning, creative
  thinking

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Parts of the Brain

• Left and Right Hemispheres
• Mirror images (roughly) of each other
• Corpus callosum carries messages between them

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Parts of the Brain

• Left hemisphere controls movements of right
  side of body
• Speech, math, calculation, logic

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Parts of the Brain

• Right hemisphere controls left side of body
• Visual/spatial relations, patterns, music, art,
  creativity, intuition

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Homework

• Get on line and look up left and right brain
  test
• Take one or more of the free online tests
• Cut and paste the results if you can
• Put results together on paper
• Describe whether you agree or disagree and why
• This is due Monday, October 20th.

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Ways to Study the Brain

• Recording Brain Activity
• Electroencephalograph (EEG) - Machine that
  records electrical activity of the brain
• Stimulation
• Electrodes implanted in certain areas of the brain

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Ways to Study the Brain

• Lesions
• Cutting out certain areas of the brains of
  animals
• Accidents
• Connections between damaged part of the brain and
  behavior

Phineas Gages Skull
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Ways to Study the Brain

• Images
• Computerized Axial Tomography (CAT) scan moving
  beam passes X-rays around and through subjects
  head to pinpoint brain injuries
• Positron Emission Tomography (PET) injecting
  radioactive solution into blood and measuring
  amount of radiation absorbed by blood cells
• Tests which brain cells are active
• Magnetic Resonance Imaging (MRI) passes
  non-harmful radio frequencies through the brain

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Endocrine System

• Sends information to and from the brain
• Messages (hormones) sent through the bloodstream
• Hormones chemical substances that carry
  messages through the body in the blood

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Endocrine System

• Hormones affect
• Growth
• Metabolism
• Physical differences in genders (testosterone)
• Help you handle stress (adrenaline)
• Influence moods and drives

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Endocrine System

• Pituitary Gland
• Control center of endocrine system
• Directed by hypothalamus in midbrain
• Controls storage of nutrients,
• Growth,
• Reproduction,
• Ovulation,
• Lactation,

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Endocrine System

• Thyroid Gland
• Produces thyroxine
• Too little lazy, lethargic
• Hypothyroidism
• Too much overactivity, sleep loss, weight loss
• Hyperthyroidism

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Endocrine System

• Adrenal Glands
• Release epinephrine and
• norepinephrine (adrenaline) into bloodstream
• Cause heartbeat/breathing to increase
• Heighten emotions (fear, anxiety)

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Endocrine System

• Sex Glands
• Testes (males) produce sperm and testosterone
• Ovaries (females) produce estrogen and
  progesterone

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Heredity and Environment

• Nature (heredity)
• Nurture (environment)
• Identical Twins
• Come from same fertilized egg and share the same
  genes
• Fraternal Twins
• Come from two fertilized eggs

Genes basic building blocks of heredity
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Group Activity Heredity Environment

• In groups of 3-4, each person will rate the
  traits below based on the influence of heredity
  or the environment total equals 100
• Each group will chart the responses and compare
  the results
• Create a chart for the group with the averages
  represented

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Group Activity Heredity Environment

• Body build
• Intelligence
• Personality
• Mathematical ability
• Baldness
• Handedness (right/left)
• Height
• Muscle ability
• Longevity