Peripheral Nervous System

  1. Pairs of Cranial nerves, #, sensory, or mixed, and the nerve they innervate.(12)
    • 1. Olfactory-(sensory), smell, innervates eyes...
    • 2. Optic-(sensory), vision,innervates eyes...
    • 3. Oculomotor-(mixed), innervates extrinsic eye muscles
    • 4. Trochlear-(mixed), innervates extrinsic eye muscles
    • 5. Trigeminal-(mixed) innervate face
    • 6. Abducen's-(mixed), innervate extrinsic eye muscles
    • 7. Facial-(mixed), innervate face
    • 8. Vestibulocochlear-(sensory) innervates ear...
    • 9. Glossopharyngeal-(mixed) innervate tongue and pharynx
    • 10. Vagus-(mixed), innervate most visceral
    • 11. Accessory-(mixed), innervate head and neck
    • 12. Hypoglossal-(mixed), innervate tongue and pharynx
  2. Describe structure of spinal chord and how many spinal nerves do we have?
    31 nerves that contain layers of protective connective tissue coverings

    Endoneurium-wraps axons (myelinated or unmyelinated)

    Fasicles-holds bundles of axons together

    Perineurium-wraps fasicles

    Epineurium-outermost covering
  3. What is Plexus?
    joined axons on both sides of body with various number of axons from anterior rami of adjacent nerves
  4. What is a reflex?
    Fast involuntary unplanned sequence of actions that occur in response to stimulus
  5. 5 functional components of reflex arc
    Sensor receptor-distal end of sensory neuron responds to stimulus

    sensory neurons-impulse from receptor travel to neuron to axon terminal in gray matter

    Inttegrating Center-One or more regions of gray matter a single synapse between sensory neuron and neuron

    Motor neuron-Impulses triggered by integrating center propagate out of CNS along motor neuron to part of body

    Effector-Responds to motor impulse such as muscle or gland, action is called reflex
  6. Describe the difference between a somatic reflex and autonomic reflex.
    Somatic Reflex(SNS voluntary)-Effectors are skeletal muscles; Involve contraction of skeletal muscles, motor responses. Conscientiously perceived. 

    Autonomic Reflex(ANS involuntary)-Effectors are glands, cardiac muscle and smooth muscles; Unconsciously perceived responses of smooth muscles cardiac muscle and glands
  7. Compare somatic nervous system and autonomic nervous system.
    • Somatic nervous system-Includes both sensory and motor neurons.
    • Effectors are skeletal muscles. 

    Autonomic nervous system-Effectors are glands, cardiac muscles and smooth muscles impulses from sensory neurons. Operates via reflex arcs.  Produces involuntary movements.
  8. What are the subdivisions of (ANS) Autonomic Nervous System
    Sympathetic and Parasympathetic
  9. Compare neurotransmitters of ANS and SNS
    ANS neurotransmitters(involuntary)-All sympathetic, parasympathetic preganglionic (myelinated) neurons and postganglionic(unmeyilinated) release ACH. 

    SNS neurotransmitters(voluntary)-All somatic motor neurons release ACH
  10. Describe what spinal nerves branch to
    • Posterior/Dorsal ramus-serve muscle and skin of posterior trunk
    • Anterior/ventral ramus- serve muscles and structures of limbs and the skin of the lateral and anterior trunk
    • Meningeal branch-supply the vertebrae, spinal chord and meninges, and rami communicantes
    • Rami communicantes-
  11. What are the sympathetic responses and what name is it also known for?
    • Fight or Flight
    • -pupils, airways dilate
    • -blood pressure increase, heart rate increase, heart contraction forced and increased
    • -Faster movement of air into lungs
    • -Blood flow decrease
    • -Urine formation, digestive activities slows or stops completely/Inhibition
    • Medulla intensify and prolong responses
    • -Release of adrenaline 
    • -Motor neurons go to sweat glands
  12. What are the Parasympathetic responses and what is it also known for?
    Rest and digest division(everything slows down; ex: after eating, you get tired)

    • -decreased heart rate 
    • -decreased diameter of airways/breathing rate
    • -decreased diameter of pupils/constriction
    • -increased salivation,lacrimation, urination, digestion, and defecation
    • -No effect on sweat glands and norepinephrine
  13. What are the locations of cell bodies?
    • Sympathetic: Neuron cell bodies located in dendrites
    • Preganglioc in the lateral horn of the thoracic and lumbar regions of spinal chord; axons leave

    Postganglionic cell bodies in ganglia next to spinal chords on both sides

    Parasympathetic- preganglionic Neuron cell bodies located in brain stem and gray matter of sacrum

    Postganglions cell bodies are in terminal ganglion
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Peripheral Nervous System