In relating the single “gate theory” to acupuncture, where is the so-called “gate” located? in the cerebrum in the thalamus at a level in the spinal cord at the point of needle contact in the cerebellum

At a level in the spinal cord  

Explanation:

The gate theory was elaborated in 1965 by P.D. Wall and r. Melzack, to explain the influence of tactile skin stimulation on pain relief. It essentially admits that there exists in the medullar posterior horns (located behind the central canal of the spinal cord) a gate-acting neural mechanism that can control the passage of nerve impulses transmitted from the peripheral fibers to the CNS through the medulla.

The gate regulates the influx of nociceptive impulses even before a perception of pain is created. The variation in the passage of action potentials (nociceptive) that the gate produces is determined by the activity of the thick (A-alpha and A-beta) and thin (A-delta and C) fibers, as well as cognitive influences.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem