<aside> 💡 The Nervous System

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1. Outline the various functions of the nervous system

   1. Sensory: response to stimuli
   2. Integration: of body processes, neuronal inputs
   3. Motor: control of effectors
      1. Involuntary effectors
         1. Smooth muscle
         2. Cardiac muscle
         3. Glands
      2. Voluntary effectors
         1. Skeletal muscles
            1. Voluntary reflex
   4. Control of reflexes
      1. Autonomic reflexes
         1. Produced by ANS
         2. Affects visceral organs
            1. Heart rate
            2. Blood pressure
            3. Glandular secretion
      2. Somatic
         1. Reflex induced by stimulation of somatic sensory nerve endings
         2. Somatic nervous system innervates skeletal muscles
         3. Protect body from injury
         4. Skeletal muscle reflexes
            1. Patellar reflex
            2. Pain/temperature withdrawal reflex

2. Describe the properties of the different functional types of neuron

   1. Sensory neurons (afferent)

      

      1. Transmit impulses toward CNS
      2. Soma located adjacent to spinal cord (dorsal root ganglion)
      3. Unipolar
         1. Cell body devoid of dendrites and presynaptic inputs
         2. Peripheral ending of axon is a modified sensory receptor

   2. Motor Neurons

      

      1. Multipolar (efferent)
         1. Motor neurons take impulses away from the CNS
         2. Soma containing multiple dendrites lies within the CNS
            1. Dendrites integrates multiple nervous inputs to create an appropriate output at NMJ
         3. Long axon in PNS carry impulses away from CNS to somatic effectors in NMJ (skeletal muscles)

   3. Interneurons

      1. 99% of CNS (100 billion neurons)
      2. Interneurons are processing neurons
         1. Inter = between
         2. Connect between neurons in CNS pathways
      3. The more complex action, the greater number of interneurons between efferent/afferent neurons
      4. Bipolar
         1. Specialized sensory
         2. Retinal cells

   Side-point:

   1. Can characterize neurons by their:
      1. Shape (pseudo-unipolar, bipolar, multpolar)
      2. In or out (afferent pathways; efferent pathways or in the CNS)
      3. What they do (sensory, motor, interneurons)

3. Outline the properties of the different classes of nerve fibres, and relate these to their functional roles

   1. Function

      

      1. Functional classification of nerves
         1. Most nerves mixture of afferent/efferent fibres and somatic/visceral
         2. Pure sensory or motor nerves are rare
         3. Classified according to direction of transmitted impulses
      2. Mixed nerves
         1. Both sensory and motor fibres
         2. Impulses to and from CNS
      3. Sensory
         1. Afferent
         2. Impulses towards CNS
      4. Motor
         1. Efferent
         2. Impulses away from CNS

   2. PNS Conduction

      1. Group A characteristics
         1. Large diameter
         2. Myelinated
         3. Somatic sensory and motor fibres
         4. Skin, skeletal muscles, joints
         5. 150m/s transmission speed
      2. Group B characteristics
         1. Intermediate diameter
         2. Lightly myelinated
         3. 15m/s transmission speed
         4. Less than 3 microns axon diameter
         5. Autonomic preganglionic nerves
      3. Group C characteristics
         1. Smallest diameter
         2. Unmyelinated
         3. 1m/s transmission speed
         4. Pain, temperature, postganglionic nerve fibres
         5. 1 microns axon diameter

4. Describe the basic components of a neural reflex arc, using the patellar reflex as an example

5. Name the major regions of the brain and describe their primary functions

6. Identify the different divisions of the peripheral nervous system and describe their functional roles

7. Describe the basic functional roles of the sympathetic and parasympathetic nervous systems and the associated neurotransmitters and receptors