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Your Amazing Brain

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Title: Your Amazing Brain


1
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

2
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.

6
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

7
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

8
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

9
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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11
Central Nervous System
  • The Spinal Cord
  • The Brain

12
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

13
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

16
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

17
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

18
The ForebrainThe Limbic System
19
The Endocrine System
20
The Endocrine System
  • The bodys slow chemical communication system a
    set of glands that secrete hormones into the
    blood stream.

21
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)

22
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.

23
The Endocrine SystemA Set of Glands
  • The Pineal Gland
  • Helps secrete melatonin which helps to regulate
    daily biological rhythms and promotes sleep.

24
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

25
Feedback System
26
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)

27
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.

32
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.

33
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.

34
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.

35
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

36
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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40
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

41
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

42
How Neurons Communicate
43
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

44
Stop!
  • Is the brain capable of reorganizing itself if
    damaged?

45
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.

46
Stop!
  • Could damaged neurons in the central nervous
    system multiply and grow back?

47
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

48
Chemical Messengers in the NS
  • Neurotransmitters
  • Endorphins
  • Hormones

49
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

50
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

51
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

52
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.

53
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.

54
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)

55
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.

56
EndorphinsNeuromodulators
  • Most endorphins act as neuromodulators, which
    alter the effect of neurotransmitters by limiting
    or prolonging their effects.

57
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.

58
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

59
Hormones
  • Sex Hormones
  • Are secreted by the gonads and by the adrenal
    glands
  • Androgens
  • Masculinizing Hormones
  • Estrogens
  • Feminizing Hormones

60
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

61
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.

62
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
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