Symptoms and their interpretation / by James Mackenzie.

  • Mackenzie, James, 1853-1925.
Date:
1912
Catalogue details

Licence: In copyright

Credit: Symptoms and their interpretation / by James Mackenzie. Source: Wellcome Collection.

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    this neighbourhood, assumes the stomach to be the seat of the pain, and thus, at the very beginning, an erroneous notion is obtained which may pervert the further steps of the examination. The unproved assumption that the mechanism by which visceral pain is produced is similar to that producing pain in the external body wall has led astray physiologists as well as clinical observers. It is assumed that stimuli which produce pain when applied to the external body wall, will likewise produce pain when applied to the viscera. It is recognised that certain nerves running from the skin to the central nervous system convey sensation, and are therefore called “ sensory.” From this it has been assumed that nerves proceeding from the viscera to the spinal cord have the same function. They are, therefore, also called “ sensory,” whereas, as a matter of fact, there is not a single observation or experiment justifying such an assumption. Though this is the interpretation usually attached to the term “ sensory ” physiologists do not now consider that a “ sensory ” nerve neces- sarily evokes sensation when stimulated, but use the term to imply an “ afferent ” nerve whatever its function may be. When making an observation upon any symptom care should be taken to record nothing beyond what, strictiy speaking, the facts warrant. If our know- ledge tells us that an organ is situated in the neigh- bourhood of the area in which a pain is felt, we should not assert the connection between the pain and the organ until we have sufficient evidence of the nature of such connection. The search for such relations will reveal things unsuspected. I may here cite an experience which occurred to me many years.