Tag Archives: Central nervous system

Spinal cord can be Regenerated with the aid of a Cancer Drug

Researchers have discovered that a cancer drug, Taxol, can reduce deterioration of the cytoskeleton and scar tissue following spinal cord injuries in rats.

A weakened cytoskeleton and impenetrable walls of scar tissue are considered by many to be the main obstacles of regeneration of nerve cells in the spinal cord.

The researchers claim Taxol was effective in promoting regeneration of injured spinal cord nerve cells in rats following spinal cord lesions. Only a few weeks following the spinal cord lesions and Taxol application, rats showed significant improvement in movements.


Sound is Produced by Vibrations in Matter (Air, Liquids, Solids)

  • Anything which causes matter to vibrate will produce sound
  • Vocal cords vibrate and push on the air flowing through the larynx, causing the air to vibrate
  • Sound cannot travel through a vacuum
  • Sound velocities:
    • Air: 344 meters/sec (770 miles/hr)
    • Water: 1500 meters/sec (3360 miles/hr)
    • Solids: about 5000 meters/sec (11,200 miles/hr)

Pitch is Determined by the Frequency of Vibration

  • We perceive fast vibrations as high pitches, slow vibrations as low pitches
  • When we are young we can hear vibrations from about 20 hertz to about 20,000 hertz


In saltatory conduction, an action potential a...

Image via Wikipedia

Nerves Have Axons, Dendrites and Cell Bodies

  • Nerve cells are designed to respond to stimuli and transmit information over long distances
  • Nerve cell has 3 parts:
    • Cell body:
      • Has single nucleus
      • Has most of nerve cell metabolism, especially protein synthesis
      • Proteins made in cell body must be delivered to other parts of nerve
    • Axon:
      • Long cylinder, designed to transmit an electrical impulse
      • Can be several meters long in vertebrates (giraffe axons go from head to tip of spine)
      • Has axonal transport system for delivering proteins to ends of cell


Chemical Transmitters Carry the Signal Across Synapses & Neuromuscular Junctions

  • A contact between 2 nerves is called a synapse
  • At the synapse there is a break in electrical transmission (the action potential cannot cross)- instead chemicals are released that carry the signal to the next nerve
    • The release of chemical transmitters at nerve endings was first shown by Otto Loewi in the frog heart
  • A neuromuscular junction (NMJ) is a contact between a nerve and a muscle- it is like a synapse, the action potential stops and the signal is carried by a chemical