Myers PSYCHOLOGY Seventh Edition in Modules

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Myers PSYCHOLOGY Seventh Edition in Modules

• Module 3
• Neural and Hormonal Systems
• James A. McCubbin, Ph.D.
• Clemson University
• Worth Publishers

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Neural Communication

• Biological Psychology
• branch of psychology concerned with the links
  between biology and behavior
• some biological psychologists call themselves
  behavioral neuroscientists, neuropsychologists,
  behavior geneticists, physiological
  psychologists, or biopsychologists
• Neuron
• a nerve cell
• the basic building block of the nervous system

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Neural Communication

• Dendrite
• the bushy, branching extensions of a neuron that
  receive messages and conduct impulses toward the
  cell body
• Axon
• the extension of a neuron, ending in branching
  terminal fibers, through which messages are sent
  to other neurons or to muscles or glands
• Myelin MY-uh-lin Sheath
• a layer of fatty cells segmentally encasing the
  fibers of many neurons
• enables vastly greater transmission speed of
  neutral impulses

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Neural Communication
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Neural Communication

• Action Potential
• a neural impulse a brief electrical charge that
  travels down an axon
• generated by the movement of positively charged
  atoms in and out of channels in the axons
  membrane
• Threshold
• the level of stimulation required to trigger a
  neural impulse

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Neural Communication
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Toilet Analogy

• When you flush, an impulse is sent down the sewer
  pipe.
• There is a short delay after flushing when the
  toilet cant be flushed again until the tank is
  refilled with water. Like a neuron, the toilet
  has a resting potential.
• When the toilet is refilled, it can be flushed
  again. Like a neuron, the toilet has a resting
  potential.
• The toilet will flush with the same intensity no
  matter how much force you place on the handle.
  Like a neuron, the toilet operates on the
  all-or-none principle.

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Neural Communication

• Synapse SIN-aps
• junction between the axon tip of the sending
  neuron and the dendrite or cell body of the
  receiving neuron
• tiny gap at this junction is called the synaptic
  gap or cleft
• Neurotransmitters
• chemical messengers that traverse the synaptic
  gaps between neurons
• when released by the sending neuron,
  neurotransmitters travel across the synapse and
  bind to receptor sites on the receiving neuron,
  thereby influencing whether it will generate a
  neural impulse

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Neural Communication
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The Neural Chain

• The neural chain is the path information follows
  when your nervous system gathers information,
  translates it into a form your brain can process,
  moves it to the brain for processing, and lets
  your body take the necessary actions.
•  

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Example

• Cells in your sensory systems gather information
  and turn it into nerve impulses. These amazing
  cells have the ability to take energy of all
  different forms and turn it into neural impulses
  your brain can understand. For example, your
  eyes have receptor cells that take light energy
  and turn it into nerve impulses. Your ears have
  similar cells. By itself your brain cant detect
  light or sound.

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Example continued

• Neurons and neurotransmitters move the impulses
  along sensory nerves to appropriate areas of your
  brain. Because the sense organs arent located in
  the brain, your nervous system must move the
  information your receptor cells receive. The
  nerves that connect the sense organs to the brain
  and spinal cord are called sensory nerves.

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Interneurons

• Interneurons in your brain and spinal cord
  process the information and determine whether an
  action is necessary. These interneurons are
  extremely important because your brain must
  process information about what you see, hear,
  taste, smell and feel. The brain has to deal
  with it all and make appropriate decisions.

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Motor Neurons

• The brain uses motor nerves to transmit
  information to parts of your body that can react
  appropriately. Without motor nerves and the
  muscles and glands that they attach to, your
  brain couldnt accomplish anything.

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Simple Reflex

• The most basic neural chain is the reflex. The
  action takes place without the brain even being
  involved.
• Lets take the example of touching a hot stove.
• When you place your hand on the heat element your
  skin receptors detect the heat and generate nerve
  impulses.
• Sensory nerves carry the information to the
  spinal cord.
• The interneurons in the brain and the spinal cord
  process the information.
• Motor neurons carry the information to remove
  your hand from the hot element and the muscles in
  the hand contract to pull your hand off the
  stove.

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The Nervous System

• Reflex
• a simple, automatic, inborn response to a sensory
  stimulus

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Neural Communication
Serotonin Pathways
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Neural Communication
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Neural Communication

• Acetylcholine ah-seat-el-KO-leen
• a neurotransmitter that, among its functions,
  triggers muscle contraction
• Endorphins en-DOR-fins
• morphine within
• natural, opiate-like neurotransmitters
• linked to pain control and to pleasure

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Norepinephrine

• Norepinephrine is a neurotransmitter that
  resembles adrenaline in its action. It is
  secreted into the bloodstream during moments of
  exertion or stress.

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Dopamine

• Dopamine is a neurotransmitter that affects
  learning, attention, and emotion. People who
  suffer from Schizophrenia have shown too much
  dopamine activity, and people who suffer from
  Parkinsons disease have an abundance of dopamine.

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Seratonin

• Seratonin is a neurotransmitter that affects
  hunger, sleep, arousal, and mood. People who
  suffer from Depression have shown low levels of
  seratonin.

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Neural Communication
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The Nervous System

• Nervous System
• the bodys speedy, electrochemical communication
  system
• consists of all the nerve cells of the peripheral
  and central nervous systems
• Central Nervous System (CNS)
• the brain and spinal cord
• Peripheral Nervous System (PNS)
• the sensory and motor neurons that connect the
  central nervous system (CNS) to the rest of the
  body

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The Nervous System
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The Nervous System

• Nerves
• neural cables containing many axons
• part of the peripheral nervous system
• connect the central nervous system with muscles,
  glands, and sense organs
• Sensory Neurons
• neurons that carry incoming information from the
  sense receptors to the central nervous system

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The Nervous System

• Interneurons
• CNS neurons that internally communicate and
  intervene between the sensory inputs and motor
  outputs
• Motor Neurons
• carry outgoing information from the CNS to
  muscles and glands
• Somatic Nervous System
• the division of the peripheral nervous system
  that controls the bodys skeletal muscles

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The Nervous System

• Autonomic Nervous System
• the part of the peripheral nervous system that
  controls the glands and the muscles of the
  internal organs (such as the heart)
• Sympathetic Nervous System
• division of the autonomic nervous system that
  arouses the body, mobilizing its energy in
  stressful situations
• Parasympathetic Nervous System
• division of the autonomic nervous system that
  calms the body, conserving its energy

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The Nervous System
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The Nervous System
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The Nervous System

• Neural Networks
• interconnected neural cells
• with experience, networks can learn, as feedback
  strengthens or inhibits connections that produce
  certain results
• computer simulations of neural networks show
  analogous learning

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The Endocrine System

• Endocrine System
• the bodys slow chemical communication system
• a set of glands that secrete hormones into the
  bloodstream

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Neural and Hormonal Systems

• Hormones
• chemical messengers, mostly those manufactured by
  the endocrine glands, that are produced in one
  tissue and affect another
• Adrenal ah-DREEN-el Glands
• a pair of endocrine glands just above the kidneys
• secrete the hormones epinephrine (adrenaline) and
  norepinephrine (noradrenaline), which help to
  arouse the body in times of stress
• Pituitary Gland
• under the influence of the hypothalamus, the
  pituitary regulates growth and controls other
  endocrine glands