<aside> 💡 Primary Tissue 4: Nerve Structure and Function

</aside>

1. Identify and recall the locations and organization of the different types of nervous tissue within the body.

   • Cells: neurons/glia
   • Tissues: grey/white matter
     • Different organization depending on complexity of information being processed
   • Organs: brain/spinal cord

   

   

   

   1. Grey matter
      1. Collection of neuronal cell bodies, largely unmyelinated
      2. Periphery of cerebral hemispheres
      3. Centrally within spinal cord
   2. White matter
      1. Bundles of axons
      2. Myelinated (gives white appearance)
      3. Connect various regions of grey matter
      4. Periphery of spinal cord, central part of brain
   3. The core of the nervous system is a hollow cavity filled with
      1. CSF
   4. CNS
      1. Location
         1. Brain and spinal cord
         2. 98% of neural tissue
      2. CNS Grey Matter
         1. Neural Cortex
            1. Grey matter on the surface of the brain
         2. Nuclei
            1. Collection of neuron cell bodies within CNS
         3. Centres
            1. Collection of neuron cell bodies in CNS with specific function
         4. High Centres
            1. Most complex centres in the brain
      3. CNS White matter
         1. Tracts
            1. Bundles of CNS axons that share common origin and destination
         2. Pathways
            1. Ascending (sensory) pathway
            2. Descending (motor) pathway
         3. Columns
            1. several tracts that form an anatomically distinct mass
   5. PNS
      1. Location
         1. Neural fibres integrated into peripheral viscera
      2. PNS Grey matter
         1. Ganglia
            1. Collection of neuron cell bodies within PNS
      3. PNS White matter
         1. Nerves
            1. Bundles of axons in the PNS

   

   6. The brain has 4 regions

   

   1. Cerebral Hemispheres: most complex/conscious; high level processing
      1. 6-layered cortex = more highly organized = more ability
      2. Aware of physical movements, speech, thought, spatial awareness, sight, hearing = processed in the cerebral hemispheres
         1. Increased processing of information/complexity = more grey matter
         2. Grey matter moves from being centrally located to the periphery
            1. Increased surface area = increased grey matter
            2. Closer to nutrition supply = blood vessels
            3. Better organization
   2. Diencephalon: somatic/subconscious activities
   3. Brain stem: somatic/subconscious activities
      1. Lots of complex activities but it is subconscious
         1. Reflexes, coordination of movement
      2. Set up during development and will continue working automatically lifelong
   4. Cerebellum: motor control, coordination, refining ongoing movements

      1. Coordinates posture, tone of muscle, muscle at a subconscious level

      2. Cortex of grey matter organized into 3 layers

         

         1. Molecular layer (outside)
         2. Purkinje layer
         3. Granular layer (inside)
   5. Spinal cord
      1. White matter for communication
      2. Organized based on direction information is travelling
         1. from receptors to brain for processing for sensory input
            1. Ascending
         2. From from brain to muscles for motor output
            1. Descending

2. Identify the 2 cell types of nervous tissue microscopically

   

   1. Neuron

   

   1. Myelinated
   2. Unmyelinated
   3. Neuroglia

3. Outline the characteristics of structure and function of nervous tissue within the body.

4. Outline the characteristics of structure and function of the 2 cell types in nervous tissue

5. Relate the structural types of the neuron to the different functions of this cell.