Nuerophysiology | Anatomy2Medicine
Neurophysiology

Nuerophysiology

  • Nerve cells and their function
    • Myelin sheath of neurons is formed by Oligodendrocytes
    • Astrocytes serve as structural element in-formation and stabilization of gray-white pattern during development.
    • Microglia work as CNS immune system.
  • EEG

 

  • Absence seizure are characterized on EEG by 3 Hz spike and slow wave
  • The EEG waves recorded from parieto-occipital region in a normal person while he is awake with eyes closed, are Alpha waves of 8-13 Hz

 

      • Sleep spindles on EEG
        • A sleep spindle is a burst of oscillatory brain activity visible on an EEG that occurs during stage 2 sleep.
          • It consists of 12–14 Hz waves that occur for at least 0.5 seconds

 

  • Sleep spindles are generated in the reticular nucleus of the thalamus.

 

 

 

  • K complexes on EEG

 

        • A K-complex is an electroencephalography (EEG) waveform that occurs during stage 2 of NREM sleep.
        • It is the “largest event in healthy human EEG”.
        • They are more frequent in the first sleep cycles.
        • K-complexes have two proposed functions:
          • first, suppressing cortical arousal in response to stimuli that the sleeping brain evaluates not to signal danger
          • second, aiding sleep-based memory consolidation.
      • The alpha-wave frequency of EEG is decreased by
        • Hypoglycaemia
        • High pCO2
        • Low serum levels of adrenoglucocorticoids
    • Drug of choice for treating “Ballismus” is Haloperidol
    • People with Migrainous Headache:
      • have Type A personality

 

  • usually have family history of migraine

 

    • are usually ambitious people
  • 6 layers of neurons are present in cerebral cortex:
  • Korbinian Brodman divided the cerebral cortex into  47 cytoarachitectonic areas, based on subtle diferences in the number and size of the cells in each of the six layers of the cortex:
  • Tactile Agnosia (astereognosis) is characterized by
    • Inability to recognize objects based on touch
    • Lesion localized at the border of somatosensory and association areas in posterior parietal lobe.
    • An isolated failure of only the highest order of feature    extraction.
    • Primary somatosensory modalities like touch, pain, pressure, temperature, vibration, and propriocep-tion are   intact

 

    • “Word deafness” is characterized by
      • Intact hearing for voices
      • Inability to recognize speech
      • Results from a disconnection of the auditory cortex from Wernicke’s area.

 

    • Ascending and descending tracts
      • Flexion of all limbs is stimulated by activation of Rubro-spinal Tract
      • Activation of Vestibulospinal tract causes all limbs to extend.
      • Corticospinal tract controls fine movements.
    • Functions of frontal lobes of human brain
      • Motivation
      • Executive Function
      • Language Production (Motor speech area) but not Language comprehension