Your Amazing Brain

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Your Amazing Brain

• Receives information within a fraction of a
  second, too minuscule to measure
• Acts on the external universe allows you to
  cry, walk, play a musical instrument
• Utilizes language one of your most advanced
  functions
• Possesses emotions creates your affective
  universe

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Your Amazing Brain

• Thinks is responsible for your memory,
  intelligence, your thoughts
• Controls your autonomic functions heart rate,
  breathing, homeostasis
• Controls your immune system protects you from
  viruses

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Peripheral Nervous System

• Handles the CNSs input and output.
• Contains all the portions of the NS outside of
  the brain and spinal cord.
• Contains sensory nerves and motor nerves
• Divided into autonomic nervous system and somatic
  nervous system.

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Peripheral Nervous System

• Sensory Nerves
• (to the brain)
• Carry messages from special reporters in the
  skin, muscles, and other internal and external
  sense organs to the spinal cord and then to the
  brain

• Motor Nerves
• (from the brain)
• Carry orders from CNS to muscles, glands to
  contract and produce chemical messengers

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Peripheral Nervous System

• Somatic NS
• Consists of nerves connected to sensory receptors
  and skeletal muscles
• Permits voluntary action (writing your name)

• Autonomic NS
• Permits the involuntary functioning of blood
  vessels, glands, and internal organs such as the
  bladder, stomach and heart

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Autonomic Nervous System

• Sympathetic NS
• Like the accelerator of your car
• Mobilizes the body for action
• Increases heart rate
• Elevates blood pressure

• Parasympathetic NS
• Like the brakes in your car
• Slows the body down to keep its rhythm
• Enables the body to conserve and store energy

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Sympathetic NSand Emotion

• You perceive the sensory stimulus.
• The adrenal gland sends two hormones epinephrine
  and norepinephrine.
• They activate the sympathetic nervous system.
• That produces a state of arousal or alertness
  that provides the body with the energy to act
  (the pupils dilate, the heart beats faster, and
  breathing speeds up).

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Central Nervous System

• The Spinal Cord
• The Brain

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The Spinal Cord

• Protected by a column of bones
• Produces some behaviors of its own without the
  help of the brain
• These spinal reflexes are automatic, requesting
  no conscious effort
• Sometimes they are influenced by thought and
  emotion
• Example touching a hot iron

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The Brain

• Areas of the Brain
• The Four Lobes of the Brain
• Lateralization

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The Hindbrain

• Medulla breathing, heart rate
• Pons sleeping, walking, dreaming
• Riticular Activating System alertness,
  attention
• Cerebellum balance, coordination for the
  muscles

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The Forebrain

• Thalamus
• Direct sensory messages to higher centers in the
  brain
• The sight of sunset is directed to a visual area
• The only sense that completely bypasses the
  thalamus is the sense of smell, which has its
  private switching station, the olfactory bulb

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The ForebrainThe Limbic System

• The Amygdala
• Responsible for evaluating sensory information
• It determines its emotional importance
• It makes the decision to approach or to withdraw
• Its initial response may be overridden by the
  appraisal of the cerebral cortex
• The Hippocampus
• The gate way to memory
• The Hypothalamus
• It is involved with drives associated with
  survival such as hunger, thirst, emotion, sex,
  and reproduction

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The ForebrainThe Limbic System
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The Endocrine System
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The Endocrine System

• The bodys slow chemical communication system a
  set of glands that secrete hormones into the
  blood stream.

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The Endocrine SystemA Set of Glands

• Thyroid gland affects metabolism
• Pancreas regulates the level of sugar in the
  blood
• Parathyroids help regulate the level of calcium
  in the blood
• Ovary secretes sex female hormones (estrogen)
• Testes secrete sex male hormone (Androgens)

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The Endocrine SystemA Set of Glands

• The Adrenal Glands
• A pair of endocrine glands just above the kidney
• They secrete epinephrine and norepinephrine which
  help to arouse the body in times of stress.

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The Endocrine SystemA Set of Glands

• The Pineal Gland
• Helps secrete melatonin which helps to regulate
  daily biological rhythms and promotes sleep.

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The Endocrine SystemA Set of Glands

• The Pituitary Gland
• A sort of master gland
• It is cherry-sized endocrine gland
• The hormones it secretes affect growth and the
  secretion of other endocrine glands
• The real boss is the hypothalamus

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Feedback System
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The Forebrain

• The Cerebrum
• Higher forms of thinking take place in it
• It is divided into two halves called the cerebral
  hemispheres that are connected by a large band of
  fibers called the corpus callosum
• They have different tasks (lateralization)

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The Forebrain

• The Cerebral Cortex
• The cerebrum is covered by several thin layers of
  densely packed cells known as the cerebral cortex
• On each cerebral hemisphere, deep fissures divide
  the cortex into 4 lobes

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The Four Lobes of theCerebral Cortex
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Functions of the Cortex

• Motor Cortex an area of the frontal lobes that
  controls voluntary movements.
• It sends messages out to the body.
• When stimulating, specific parts of the
  region in the left or right hemisphere, specific
  body parts moved on the opposite side of the
  body.

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Functions of the Cortex

• Sensory Cortex the area at the front of the
  parietal lobes that receives, registers, and
  processes body sensations.
• Association Functions areas of the cerebral
  cortex that are not involved in primary motor or
  sensory functions rather, they are involved in
  higher mental functions such as learning,
  remembering, thinking, and speaking.

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Functions of the Cortex

• Language
• 1- Brocas Area an area of the frontal lobe,
  usually in the left hemisphere, that directs the
  muscle movements involved in speech
• 2- Wernickes Area a brain area involved in
  language comprehension and expression usually in
  the left temporal lobe.

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Specialization and Integration in Language

• 1- Visual cortex receives written words as
  visual stimulation.
• 2- Angular gyrus transforms visual
  representations into an auditory code.
• 3- Wernickes area interprets auditory code.
• 4- Brocas area controls speech muscles via the
  motor cortex.
• 5- Motor cortex word is pronounced.

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Lateralization

• Left Hemisphere
• Verbal competence
• Speaking, reading, thinking reasoning
• Processes info in sequence
• One piece of data at a time
• logical

• Right Hemisphere
• Nonverbal areas
• Comprehension, spatial relationships, drawing,
  music, emotion
• Processes info. As a whole
• intuitive

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Emotion and Lateralization

• Left Hemisphere
• Important for the expression of positive emotion
• Damage to the L.H. leads to loss of the capacity
  of joy.
• Activation in the L.H. leads to tendencies to
  approach other people.

• Right Hemisphere
• Important for the expression of negative emotion
• Damage to the R.H. may make people euphoric.
• Activation in the R.H. leads to tendencies to
  withdraw from people.

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Neurons

• The NS is made up in part of neurons
• They are held in place by glial cells
• The Function of Glial Cells
• Provide neurons with nutrients
• Insulate neurons
• Remove cellular debris when neurons die

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The Structure of the Neuron

• 1- Dendrites
• Act like antennas receiving messages
• 2- The Cell Body
• Contains the biochemical machinery to keep the
  neuron alive
• 3- The Axon
• Transmits messages away from the cell body to
  other neurons

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How Neurons Communicate
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Myelin Sheath

• Surrounds the axons
• A layer of fatty material, which is derived from
  glial cells
• There are 2 purposes of the myelin sheath
• To prevent signals from adjacent cells from
  interfering with each other
• To speed up the production of neural impulses

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Stop!

• Is the brain capable of reorganizing itself if
  damaged?

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Plasticity

• When one brain area is damaged, other areas may
  in time reorganize and take over some of its
  functions.
• If neurons are destroyed, nearby neurons may
  partly compensate for the damage by making new
  connections that replace the lost ones.
• Examples How the sense of touch in blind men
  invades the visual part of the brain.
• How the brain struggles to recover from a
  minor stroke.

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Stop!

• Could damaged neurons in the central nervous
  system multiply and grow back?

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Precursor Cells(Immature Cells)

• Precursor cells can give birth to new neurons
  when immersed in a growth-promotion protein
• Physical and mental exercise promote the survival
  and the production of new precursor cells
• Stress can prohibit the production of new cells
• Nicotine can kill precursor cells

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Chemical Messengers in the NS

• Neurotransmitters
• Endorphins
• Hormones

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Neurotransmitters

• Neurotransmitters travel from one neuron to
  another. Changes occur in the receiving neurons
  membrane,
• The ultimate effect is either
• Excitatory the probability that the receiving
  neuron will fire increases
• Inhibitory the probability that the receiving
  neuron will fire decreases

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Neurotransmitters

• Serotonin
• Sleep, appetite, sensory perception, temperature
  regulation, pain suppression, and mood
• Dopamine
• Voluntary movement, learning, memory, and emotion
• Acetylcholine
• Muscle action, cognitive functioning, memory, and
  emotion

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Neurotransmitters

• Norepinephrine
• Increased heart rate and the slowing of
  intestinal activity during stress, learning,
  memory, dreaming, waking from sleep, and emotion
• GABA
• (gama-aminobutyic acid)
• The major inhibitory neurotransmitter in the brain

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Why Not Flood the Brain with Artificial Opiates?

• The brain may stop producing its own natural
  opiates.
• For a drug addict, the result is agony until the
  brain resumes production of its natural opiates
  or receives more artificial opiates.

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Is Designing a Drug Easy?

• Dopamine as a drug doesnt help because dopamine
  doesnt cross the blood-brain barrier by which
  the brain fences out unwanted chemicals
  circulating in the blood.
• L-dopa, a raw material the brain can convert to
  dopamine, can sneak through the fence.

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How Drugs and Other Chemicals Alter
Neurotransmitters

• The agonist molecule excites. It mimics the
  effects of a neurotransmitter on the receiving
  neuron.
• Morphine mimics the action of neurotransmitters
  by stimulating receptors in the brain involved in
  mood and pain sensation.

• The antagonist molecule inhibits by blocking the
  neurotransmitters or by diminishing their
  release.
• Botulin poison causes paralysis by blocking
  receptors for acetylcholine (a neurotransmitter
  that produces muscle movement)

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Endorphins

• They have an effect similar to that of opiates.
• They reduce pain and promote pleasure.
• They play a role in appetite, sexual activity,
  blood pressure, mood, learning, and memory.
• Some endorphins function as neurotransmitters.

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EndorphinsNeuromodulators

• Most endorphins act as neuromodulators, which
  alter the effect of neurotransmitters by limiting
  or prolonging their effects.

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Hormones

• Insulin
• Produced by the pancreas
• Regulates the bodys use of glucose affects
  appetite
• Melatonin
• Secreted by the pineal gland
• Helps to regulate daily biological rhythms and
  promotes sleep.

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Hormones

• Adrenal Hormones
• Produced by the adrenal glands are involved in
  emotion and stress. They rise in response to
  nonemotional conditions, such as cold, heat, pin
  injury, and physical exercise, and in response to
  some drugs such as caffeine and nicotine.
• The Outer Part
• Cortisol
• The Inner Part
• Epinephrine (adrenalin) Norepinephrine

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Hormones

• Sex Hormones
• Are secreted by the gonads and by the adrenal
  glands
• Androgens
• Masculinizing Hormones
• Estrogens
• Feminizing Hormones

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Neurotransmitters Hormones

• Acetylcholine
• Shortage in acetylcholine may be associated with
  Alzheimers disease
• Dopamine
• The degeneration of brain cells that produce and
  use another neurotransmitter, dopamine, appears
  to cause symptoms of Parkinsons disease.
• Low levels of dopamine may cause ADHD

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Neurotransmitters Hormones

• Serotonin
• Decrease in norepinephrine and serotonin is
  associated with depression. Elevated levels
  along with other biochemical and brain
  abnormalities have been implicated in childhood
  autism.
• Norepinephrine
• Norepinephrine, epinephrine, and adrenaline are
  associated with excitement and stress.

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Neurotransmitters Hormones

• Cortisol
• Cortisol is associated with stress. Increase in
  cortisol damages the brain and may be associated
  with posttraumatic stress.
• GABA
• Abnormal GABA levels have between implicated in
  sleep and eating disorders and in compulsive
  disorders.
• Glutamate
• Glutamate, serotonin, and high levels of dopamine
  have been associated with schizophrenia