Exam 1 Biological Explanations and Synapses Flashcards
What do dendritic spines do?
They increase the area available for synapses
The all-or-none law contains which of the following?
The axon
According to the idea of a tripartite synpase, what does an astrocyte do at a synapse?
releases chemicals to modify input to a receiving cell
After the peak of the action potential, what brings the membrane back to its resting potential?
potassium ions flow passively out of the cell
Where does a “second messenger” carry its message?
within the postsynaptic neuron
what type of synaptic receptors can produce effects that last minutes?
metabotropic
Most neurotransmitters are synthesized from what type of chemical?
amino acids
what determines the type of effect a neurotransmitter exerts on the postsynaptic neuron?
the postsynaptic neuron’s receptors
what do the vesicles in a neuron do
they store neurotransmitters
What was unique about the time when Golgi and Cajal shared the nobel prize?
their acceptance speeches contradicted each other
about how many neurons are in the human brain, and how variable is it?
86 billion and people vary in their neuron number more than they do in height
When the membrane is at rest, why don’t sodium ions enter the cell?
the sodium gates are closed
what education is usually necessary for someone to direct a research laboratory?
a doctorate degree
what is the absolute refractory period of an axon?
the time when it is incapable of producing an action potential
how does a graded potential differ from an action potential?
a graded potential can be either excitatory or inhibitory
which neurotransmitter also dilates blood vessels
nitric oxide
when would a researcher be most likely to observe spatial summation?
after simultaneous subthreshold stimuli at neighboring locations
what is the function of a reverse transmitter?
it tells the presynaptic neuron to increase its release
what causes an action potential?
sodium ions entering the cell
the transmitter serotonin is synthesized from which component of the diet?
the amino acid tryptophan
