Nomenclature

Through the use of these various techniques, the autonomic physiologists were able to appreciate the design and overall functions of the autonomic nervous system. For many years, the whole system was called the 'sympathetic nervous system', with the word 'sympathetic' coming from 'sympathy', suggesting the co-ordinated action of the system. The vertebral chains were called the 'great sympathetic nerves', and were clearly involved in coordinating activity, and many of the autonomic responses of the body could be observed to activate together, such as the famous set of 'flight or fight' responses, which included aspects as diverse as dilation of the pupil, increase in the heart rate, redistribution of blood flow to the muscles, suppression of activity in the gut, etc., all co-operating in preparing the body for activity.

The two scientists most responsible for establishing our basic knowledge of the system were Gaskell (Box 1.2) and Langley (Box 1.3). By 1866, Gaskell had given the first clear account of the overall structure of the system, with its origin in the cranial, thoracolumbar and sacral outflows from the brainstem and spinal cord. From 1875, Langley and Gaskell were close colleagues both working in Cambridge, with Langley's functional and Gaskell's anatomical studies allowing cross-fertilisation of ideas. The

Box 1.2 Walter Holbrook Gaskell (1847-1914)

Gaskell was born in Naples. He studied mathematics at Trinity College, Cambridge, and then transferred to the Physiology Department, He qualified in medicine at University College, London. He returned to Cambridge in 1875 as a research scientist in the Physiological Laboratory with private means. He became a University Lecturer in 1883 and a fellow of Trinity College, Cambridge in 1889. Working initially on the control of the cardiovascular system, he widened his interests to undertake an extensive examination of the anatomy and physiology of the autonomic nervous system. He revealed the presence of the complementary sympathetic and parasympathetic divisions.

overall term 'autonomic nervous system' was first suggested by Langley in 1898, but did not gain general acceptance at the time. In his textbook in 1916, Gaskell called it 'the involuntary nervous system'. In 1921, Langley published his book, The Autonomic Nervous System, in which he proposed that the system could be divided on functional and anatomical grounds into three components: the sympathetic nervous system, producing coordinated activity using the thoracolumbar outflow; the parasympathetic nervous system, producing more individual actions often opposing the sympathetic and using the cranial and sacral outflows; and the enteric nervous system. The rationale for treating the enteric nervous system as a separate system came from his estimation that it could not be classified as

Langley was born in Newbury. He studied mathematics at St John's College, Cambridge, later transferring to natural science. He spent his entire scientific career in the Physiological Laboratory; initially as a demonstrator in 1875, then as University Lecturer in histology in 1884, and as Professor of Physiology from 1903 to 1925. With Gaskell, he determined the anatomical and principal physiological functions of the autonomic nervous system. He was also the owner and editor of the Journal of Physiology from 1894 until his death, and through this played a major role in shaping British physiology. He was a keen sportsman and member of the National Skating Association, and a judge of international skating competitions.

Box 1.3 John Newport Langley (1852-1925)

parasympathetic, since the number of vagal fibres innervating the gut was far less than the number of neurones in the gut wall, and also from the demonstration that the reflex activity of the gut (e.g. peristalsis) did not alter when its extrinsic innervation was cut and no connection remained with the central nervous system.

chapter i Although in retrospect Langley's classification was the most sensible

Historical one, and one that is accepted today, for many years the enteric system was

Background largely ignored, and the main focus was on the sympathetic and parasym pathetic systems. However, the term 'sympathetic nervous system' for the whole autonomic system was retained by many, particularly in Europe, and even as late as the 1950s there were still arguments over terminology, since it was illogical for many physiologists to refer to the parasympathetic system as part of the sympathetic nervous system, since 'para' means 'alongside'. At a Physiological Society Meeting in 1954, it was proposed that if the whole thing was to be the 'sympathetic' nervous system, then the two main divisions might be the 'parasympathetic' and 'orthosympathetic' systems (a light-hearted alternative put forward by Bernard Katz at that meeting was 'unsympathetic'!).

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