BIO PSYCH 12E CH2
When an action potential reaches the end of an axon, it evokes the release of neurotransmitters by opening ____ channels in the axon terminal.
calcium
Glutamate opens sodium gates, enabling sodium ions to enter the postsynaptic cell. What type of effect is this?
ionotropic
Which process is more typical of a metabotropic effect than an ionotropic effect?
Producing long-lasting effects on the post-synaptic cell
Which event is most likely to be dependent on ionotropic effects?
Rapid muscle contraction
What is the primary difference between temporal summation and spatial summation?
Spatial summation depends on contributions from more than one sensory neuron.
What happens when a neurotransmitter is released by a presynaptic cell?
The neurotransmitter passively spreads across the synaptic cleft.
Insulin increases the entry of tryptophan into the brain by ____.
causing certain competing amino acids to enter other cells, outside the brain
Loewi demonstrated that synapses operate by the release of chemicals by ____.
collecting fluid from a stimulated frog's heart, transferring it to another frog's heart, and measuring that heart rate
In a reflex arc, the coordination between contraction of certain muscles and relaxation of others is mediated by ____.
interneurons
A receptor can directly open a channel and thereby exert a(n) ____ effect, or it can produce slower but longer ____ effects.
ionotropic; metabotropic
The "spontaneous firing rate" of a neuron refers to ____.
its rate of producing action potentials even when it is not stimulated
A drug that inhibits the action of the enzyme acetylcholinesterase will have the effect of ____.
prolonging the action of acetylcholine at its synapses
Sherrington deduced that transmission at a synapse must be slower than conduction along an axon. This was based on what kind of evidence?
the speed of reflexive responses
The presynaptic terminal stores high concentrations of neurotransmitter molecules in ____.
vesicles