Neurological%20Control%20of%20Movement

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Neurological Control of Movement

• The Structure and Function of the Nervous System

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The Neuron

• The Cell Body (nucleus)
• The Dendrites
• the receivers
• The Axon
• the transmitter
• contains the axon
• terminals
• contains the synaptic knobs that release
  chemicals known as neurotransmitters.
• The axon hillock decides if the impulse is a
  graded potential or an action potential.

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The Neuron

• Node of ranvier
• Myelin sheath
• Saltitory conduction the impulse skips from node
  to node and is a faster method of impulse travel.

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The Nerve Impulse

• Nerve Impulse an electrical charge that passes
  from one neuron to the next neuron or muscle
  fiber.
• Resting Membrane Potential the separation of
  charges across the membrane (polarized).
• a constant RMP of -70 mV is the function of the
  sodium-potassium pump.
• Depolarization when the charge difference
  decreases (lt -70 mV), moving closer to zero (ie
  -20 mV).
• Hyperpolarization when the charge difference
  increases (gt -70 mV), moving farther from zero
  (ie -120 mV).

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The Nerve Impulse

• Graded Potentials local changes in the neuron
  membrane to cause an inefficient charge
  difference.
• Action Potentials a rapid and substantial
  depolarization (excitation) of the neurons
  membrane.
• axon hillock- measures the summation of impulses
  and determines the threshold for an action
  potential
• All-Or-None Principle
• Sequence of events 3.2

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The Synapse

• Synapse is the site of impulse transmission from
  one neuron to another neuron or muscle fiber.
• axon terminals- release acetylcholine
• synaptic cleft
• receptors- of a neuromuscular junction at the
  sarcolemma of a muscle fiber. 3.4

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The Synapse

• Excitatory Postsynaptic Potential (EPSPs) can be
  either depolarizations (excites) or
  hyperpolarizations (inhibits)
• Inhibitory Postsynaptic Potentials (IPSPs) are
  only hyperpolarizations (inhibits)

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Organization of the Nervous System
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The Brain and Spinal Cord

• Cerebrum site of mind and intellect, motor
  control, sensory input and interpretation.
• Frontal Lobe general intellect and motor control
• Temporal Lobe auditory input and its
  interpretation
• Parietal Lobe general sensory input and its
  interpretation
• Occipital Lobe visual input and its
  interpretation

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The Brain and Spinal Cord

• Diencephalon sensory integration and homeostasis
  of the bodys internal environment.
• Thalamus interprets sensory input and relays it
  to the appropriate area of the brain.
• Hypothalamus maintains homeostasis.

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The Brain and Spinal Cord

• Cerebellum movement control.
• Brain Stem relays information between the brain
  and the spinal cord.
• Spinal Cord tracts of nerve fibers that allow
  two-way conduction of nerve impulses.
• afferent -vs- efferent

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The Peripheral Nervous System

• The PNS contains 12 pairs of cranial nerves and
  31 pairs of spinal nerves.
• Sensory neurons enter the spinal cord through the
  dorsal root.
• mechanoreceptors (touch)
• thermoreceptors (temperature)
• nociceptors (pain)
• chemoreceptors (oxygen,
• glucose, electrolytes, etc.)
• kinesthetic receptors (movement in joints,
  balance, etc.) ie. golgi tendon organs

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The Peripheral Nervous System

• Motor neurons leave the spinal cord through the
  ventral root.
• Create muscle contraction
• Create muscle inhibition

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The Autonomic Nervous System

• The ANS controls your bodys involuntary internal
  functions.
• Sympathetic Nervous System (fight or flight
  mechanism)
• inc. H.R. and cardiac contraction
• coronary vessels dilate increasing B.P. blood
  flow
• bronchodilation, inc. metabolic rate mental
  capabilities
• glucose is released from the liver into the blood

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The Autonomic Nervous System

• Parasympathetic Nervous System (housekeeping
  system)
• carrys out digestion, urination, life support
• conserves energy
• decreases blood flow
• decreases breathing rate

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Sensory Motor Integration

• Sensory Motor Integration is the communication
  of the sensory and motor nerve pathways. 3.1
• Reflex when sensory impulses terminate at the
  spinal cord and are integrated there.
• Motor Control controlled by impulses conducted
  by motor (efferent) neurons from the brain.
• Muscle Spindles create reflexive muscle
  contractions of the agonist muscle to resist
  further stretching.
• Golgi Tendon Organs are sensitive to tension
  which excite the antagonist muscles to contract.

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Muscle Fiber Recruitment

• Each muscle fiber is innervated by only one motor
  neuron, but each motor neuron innervates up to
  several thousand muscle fibers.
• Principle of Orderly Recruitment
• Motor units with smaller motor neurons (ST) will
  be recruited first, larger motor neurons (FTb)
  last.
• Motor units with a smaller number of muscle
  fibers will be recruited first.