Question

question 10 1 pts
____ signals stimulate neurons and make them more likely to fire; ____ signals make neurons less likely to fire. a balance of the two determines whether a given neuron will fire.

options:

• synaptic; inhibitory
• excitatory; inhibitory
• excitatory; synaptic
• inhibitory; excitatory

Explanation:

To solve this, we analyze the roles of neural signals:

• Excitatory signals increase a neuron's likelihood of firing (depolarize the membrane, moving toward the action potential threshold).
• Inhibitory signals decrease a neuron's likelihood of firing (hyperpolarize the membrane, moving away from the threshold).

Now we evaluate the options:

• "synaptic; inhibitory": Synaptic refers to the junction, not the signal type affecting firing likelihood, so incorrect.
• "excitatory; inhibitory": Matches the definitions of excitatory (stimulates, more likely to fire) and inhibitory (less likely to fire) signals.
• "excitatory; synaptic": Synaptic is not a signal type for reducing firing likelihood, incorrect.
• "inhibitory; excitatory": Reverses the roles (inhibitory should decrease, excitatory increase), incorrect.

Answer:

B. excitatory; inhibitory (assuming the option with "excitatory; inhibitory" is labeled as such, e.g., if the second option is B, then B. excitatory; inhibitory)