Question

which of the following best describes spatial summation?
integration of postsynaptic potentials from adjacent neurons
integration of postsynaptic potentials from multiple presynaptic neurons
amplification of a single postsynaptic potential
generation of action potentials in the postsynaptic neuron
inhibition of presynaptic neurons
question 8
astrocytes play a role in maintaining the blood - brain barrier and regulating the extracellular environment of neurons.
true
false

Explanation:

• For the first question: Spatial summation is the integration of postsynaptic potentials from multiple presynaptic neurons. It is about combining signals from different neurons (spatial aspect - multiple sources in space) rather than adjacent neurons (which is more about location in a line), amplifying a single potential (that's not summation), just generating action potentials (summation is a step before that in some cases), or inhibiting presynaptic neurons (not the core of summation).
• For the second question: Astrocytes are glial cells. They have end - feet that cover the endothelial cells of the blood - brain barrier, helping to maintain its integrity. They also take up and release ions and neurotransmitters, regulating the extracellular environment of neurons.

Answer:

• First question: Integration of postsynaptic potentials from multiple presynaptic neurons
• Second question: True