What does it mean to say that action potentials are “all or none”?

Given that graded potentials fade over distance, what type of synapse would be the most effective in starting or inhibiting an action potential?

Why does an action potential move in an all-or-nothing fashion down the length of an axon without stopping?

What is a post-synaptic potential and how is it caused? Describe the two types of post-synaptic potentials that can occur. Within this context, what does excitatory and inhibitory mean?

How do local potentials and action potentials differ?

What are the two main factors that influence the conduction speed of an action potential along an axon?

Starting with the action of a neurotransmitter at the postsynaptic end of a neuron, what happens to generate an action potential to a second neuron?

What terms denotes a sudden change (depolarization and repolarization) in the electrical properties of the neuron membrane? Action potential  Synaptic transmission  Event-related potential Postsynaptic potential ------------------------------------ You step on a brick, ouch. What type of nerve will bring the signal from your foot to your brain? Somatic afferent  Somatic efferent  automatic afferent  automatic afferent ---------------------------------------------- A given neurotransmitter is inhibitory. What might its receptors do?   Allow positive ions to enter the cell Allow negative ions to enter the cell  Allow positive ions to leave the cell B and C

Which of the following is the role of axonal Calcium (Ca2+) channels in neuronal communication at the synapse? a) they inhibit the action potential causing it to stop b) Calcium channels have no role in this process c) by allowing calcium to exit the cell, they promote the propagation of action potential across the synapse by creating depolarization d) by blocking calcium entrance, they mediate the contraction of presynaptic axon to facilitate movement e) when they open, calcium enters the presynaptic terminal, promoting fusion of neurotransmitter vesicles with presynaptic membrane, and release of neurotransmitters to the synaptic cleft

Which of the following statements concerning synapses is FALSE? O A) Modulation of synaptic strength can be presynaptic of postsynaptic B) High frequency stimulation in the presynaptic neuron often leads to DECREASED neurotransmitter release O C) Modulation of synaptic strength can either be short term, lasting seconds, or long term, lasting as long as a lifetime. D) Agonists are drugs that mimic neurotransmitters and antagonists are drugs that block the action of neurotransmitters O E) Certain drugs prevent the reuptake of neurotransmitter from the synapse