Flashcards in Physiology: Neurones, nerve conduction and synaptic transmission Deck (21)
What is retrograde transport, in the context of neurones?
The fact that material can be transported between the soma (cell body) and presynaptic terminal and vice versa.
Name three disease processes that make use of retrograde transport to infect neurones?
Give an example of a unipolar neurone
Peripheral autonomic neurone
Give an example of a pseudounipolar neurone
Dorsal root ganglion
Give an example of a bipolar neurone
Retinal bipolar neurone
Give an example of a multipolar neurone
Lower motor neurone
What is the length constant (λ)?
A constant used to quantify the distance that a graded electric potential will travel along a neurite via passive electrical conduction.
Will the local current spread be longer or shorter with a larger length constant
What is the most common excitatory neurotransmitter in the CNS?
What is the most common inhibitory neurotransmitter in the CNS?
GABA ( γ-aminobutyric acid) or glycine
Is a excitatory response depolarizing or hyperpolarizing?
Is an inhibitory response depolarizing or hyperpolarizing?
What kind of receptors does glutamate activate?
Cation selective, ionotropic glutamate receptors
What kind of receptors does GABA or glycine activate?
Anion selective ionotropic recpetors
What are the three main morphological types of synpase. List from most common to least common!
What is a synapse?
A junction between two neurones (most commonly between the axon terminal of one neuron and the dendrites or cell body of the next)
Describe briefly the events that occur at a synapse
1. Action potential triggers the opening of voltage gated calcium channels
2. This causes the release of neurotransmitter from some of the synaptic vesicles into the synaptic cleft.
3. This neurotransmitter diffuses across the synaptic cleft and binds with specific protein receptor sites and activates changes the ion permeability there.
With regard to Na+ and K+ describe the differences between excitatory and inhibitory synapses.
Change in permeability at excitatory synapses results in the influx of sodium into the postsynaptic neurone whereas inhibitory synapses result in the influx of chlorine into the postsynaptic neurone.
Name three amino acid neurotransmitter substances
Name 5 amine neurotransmitters