Who Discovered the Body’s Reflex Actions?
The theory explaining the body’s reflex, or involuntary, actions was formulated by Marshall Hall (1790—1857), an English physician. Hall studied in Edinburgh, Paris, Gottingen (Germany) and Berlin. Finally he settled in London and there carried out a seven-year study of the reflex action of the spinal system which culminated in 1837 in the publication of his most important paper, “On the Reflex Function of the Medulla Oblongata and the Medulla Spinalis” (1832), which was supplemented in 1837 by another On the True Spinal Marrow, and the Excito-motor System of Nerves.
(The medulla spinalis is the spinal cord and the medulla oblongata is its continuation, forming the hind-most segment of the brain.)
In this theory, he stated that the spinal cord is comprised by a chain of units that functions as independent reflex arcs, and their activity integrates sensory and motor nerves at the segment of the spinal cord from which these nerves originate. He proposed in addition that those arcs are interconnected and interacting in the production of coordinated movement.
A reflex movement is one of the simplest forms of activity performed by the nervous system. A good example is the immediate jerking away of the hand if it touches a hot stove. The involuntary action is caused by a nerve cell being stimulated by the heat of the stove to send an immediate impulse down the nerve. This causes the muscle to contract.
Another reflex is the sudden narrowing of the eyes against bright light. Doctors make use of reflexes to check the health of the nervous system. A tap below the knee with a mallet, for example, should elicit a jerk of the leg.
Marshall Hall’s scientific explanation of these movements was at first greeted with criticism and ridicule, and the Royal Society refused to publish his paper. But his ideas met with a more sympathetic response by some European scientists whose studies confirmed the validity of his principles. Hall thus became the authority on the multiform deranged states of health referable to an abnormal condition of the nervous system, and he gained a large practice.