Which of the marked area is involved in relieving pain when painful site is massaged?
High-Yield Explanation
Ans. A. A (Substantia gelatinosa)The gate-control theory of pain postulates that massage may be effective in closing the gate--that is, inhibiting the transmission of noxious stimuli by stimulating large nerve fibers.When pressure fibers are stimulated (Ab) it inhibits pain fibers via gelatinosa interneurons.* The marking area A is substantia gelatinosa.* Massage stimulates A-beta fiber, which acts on gelatinosa neuron (G neuron) of dorsal of spinal cord.* G neuron in turn inhibits small diameter pain fiber (closing the gate at the spinal cord level.* This theory was proposed by Melzack & Wall and is also known as gate control theory of pain.