Question

Spatial summation refers to

A) electrical signals reaching neurons from outer space.
B) multiple graded potentials arriving at one location simultaneously.
C) repeated graded potentials reaching the trigger zone one after the other.
D) suprathreshold potentials triggering action potentials that are extra large.
E) all of the above

Answer 1

Spatial summation refers to multiple graded potentials arriving at one location simultaneously.

Step-by-step explanation:

Spatial summation refers to multiple graded potentials arriving at one location simultaneously. This means that the graded potentials from different presynaptic elements add up and reach the trigger zone at the same time, potentially initiating an action potential in the postsynaptic neuron. Spatial summation can be contrasted with temporal summation, which involves the summation of graded potentials at the same location on a neuron, but separated in time.