L1-3 quiz

• the cerebellum is a part of the brain that co-ordinates balance and posture, whereas the brainstem is responsible for respiratory control
• an action potential involves the flux of which ions across the axonal membrane:


  Na+, K+ (sodium ions flow in, potassium ions flow out)
• types of glial cells:

  astrocytes, Schwann cells, oligodendrocytes, microglia, ependymal cells
• transfer of information at a chemical synapse:

  • calcium flows into the pre-synaptic nerve terminal
  • synaptic vesicles fuse with the presynaptic membrane
  • transmitter is released into the synaptic cleft
  • transmitter binds with receptors in the post-synaptic membrane
  • a response is elicited in the post-synaptic neuron
• dendrites:

  • contact terminals of other neurones (synaptic boutons-sites of communication)
  • no sheath
  • short (curly)
  • bristle-like
  • arise from the cell body
• properties of the neuronal action potentials:

  • can jump from one node of Ranvier to the next
  • involve the influx of Na+ ions into the axon
  • originate at the axon hillock
  • intensity depends of frequency of action potentials over a period of time
• axon structurally specialised:

  • thin
  • many microtubules
  • long
• an oligodendrocyte provides part of the myelin sheath for many axons in the central nervous system, whereas a Schwann cell provides part of the myelin sheath for a single axon in the peripheral nervous system