Neurophysiology Revision Flashcards
Myelin sheaths forms what?
Internodes
What is the function of myelination?
To reduce the size of neurons but maintain or increase speed. This is because it acts as insulation.
What cells are responsible for myelination in the peripheral nervous system?
Schwann cells
What cells are responsible for myelination in the central nervous system?
Oligodendrocytes.
What is the synaptic cleft?
The gap between the presynaptic cells (bouton) and the postsynaptic cells
What allows for the docking of vesicles?
The pairing of the t-SNARE and v-Snare molicules.
What prevents the exocytosis of vesicles and how is the overcomed?
Complexin prevents the exocytosis. Calcium release induces synaptotagmin to displace complexin and allows exocytosis to proceed.
What are the two different neurotransmitter receptors?
- Ionotropic
- Metabotropic (slow response as it requires intracellular components.)
What is the difference between excitatory and inhibitory responses?
Excitatory - Increase depolarisation
Inhibitory - Decrease depolarisation meaning it requires a greater stimuli to cause an action potential as the resting membrane potential is more negative.
What is the difference between spatial summation and temporal summation?
Spatial - Action potentials from different axons generate an action potential.
Temporal - Repeated action potentials from the same axon.
How do receptors respond to a strong sensory stimuli?
By increasing the frequency of action potentials
What are the different responses from a sensory stimuli?
- Slowly adapting
- Rapidly adapting.
