EXAM1-Neurons-Quiz
The ion necessary to initiate the release of acetylcholine into the synaptic cleft is chloride zinc potassium sodium calcium
calcium
The pattern of synaptic connectivity where a large number of presynaptic neurons provide input to a single postsynaptic neuron, is known as saltatory conduction divergence convergence integration
convergence
Neurotransmitters are usually released into synapses by __________. protein-mediated transport active transport exocytosis simple diffusion
exocytosis
Spatial summation refers to electrical signals reaching neurons from outer space. repeated graded potentials reaching the trigger zone one after the other suprathreshold potentials triggering action potentials that are extra-large. multiple graded potentials arriving at one location.
multiple graded potentials arriving at one location.
If a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitudes arrive at the trigger zone at the same time, what is most likely to occur? The cell dies. Nothing. They will cancel each other out. An action potential is fired off more quickly than usual. The cell becomes hyperpolarized. The cell becomes easier to excite because it depolarizes
nothing
Inhibitory postsynaptic potentials (IPSPs) increase membrane permeability to sodium ions decrease potassium ion exit from the cells. decrease calcium ion exit from cells result in depolarizations result in hyperpolarizations.
results in hyperpolarizations
You were hired to work on a research project to design a drug. Which of these drug mechanisms would decrease the amount of neurotransmitter in the synaptic cleft? decreasing diffusion inhibiting enzymes (like MAO) that break down neurotransmitters stimulating uptake blocking receptors with an antagnoist
stimulating reuptake
The space between the presynaptic neuron and the postsynaptic neuron is called the soma synapse synaptic cleft synaptic void
synaptic cleft
When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs? temporal summation hyperpolarization decrease in speed of impulse transmission inhibition of the impulse spatial summation
temporal summation
The total amount of neurotransmitter released at the axon terminal is directly related to the length of the axon total number of action potentials amplitude of the action potential. amplitude of the graded potential
total number of action potential