Nervous Tissue

Locate the spinal cord with the naked eye. Survey the cord under the low power of your microscope and identify, at the surface of the cord, the meniges(dura and arachnoid), nerve rootlets in oblique or cross sections, dorsal root(sensory) ganglia, blood vessels. Epidural fat is seen. Identify the anterior(ventral) median sulcus, posterior(dorsal) median fissure and the ependymal canal(in the centre of the cord) lined by columnar ependymal cells. Try to demarcate the boundary between the white and the grey matter of the spinal cord. Examine the grey matter under high-dry(X40)
  1. Could you identify the perikarya(soma, cell bodies) of the motor neurons in the ventral(anterior) horn? Identify also the nucleus, nucleolus and Nissl substance in the neurons. Arising from the perikaryon are a variable number of dendrites in short segment.
  2. Between the neurons are the nuclei of neuroglail cells. It is difficult to classify them into types in paraffin section. Review the functions of the various neuroglial cells.
  3. Are the capillaries identifiable in the grey matter?
Examine the white matter under high-dry(X40)
  1. Is the texture of the nervous tissue in the white matter identical to that of the grey matter? How would you describe the appearance of the white matter? The clear space between the nerve fibre and the myelin sheath is an artefact.
  2. Are neuroglial cells present in the white matter?
  3. Do you see any blood vessels in the white matter?