The interest in the segmental basis of cutaneous sensory
innervation evinced by the ancient Greeks was developed into a
major contribution to experimental biology by the studies in man
and animals by Sherrington, Head and Foerster. The present study
is one of a number of more recent investigations of the dermatomes
in animals from which a great deal of comparative information has
been obtained. The particular significance of a study of the
functional anatomy of the sheep in relation to veterinary medicine
has been discussed.
The experimental work described in this thesis involved
particular consideration of the following
1. The features of the topographical anatomy of the vertebral
column of the sheep which were found to be of importance in the
2. The value of the "remaining sensibility" technique as a
means of defining the dermatomes of the sheep.
3. The use of figurines and photographs in the schematic
representation of the experimental results.
4. The justification for basing the definition of the
dermatomes largely on the responses to pinch stimuli.
5. A discussion of the features of the dermatomes of the
sheep in relation to embryological development and the
observations which have been made in other species.
6. The changes in muscle tonus in the limbs which followed
section of the dorsal spinal nerve roots or damage to the
7. The aberrations in feeding, defecation, micturition and
respiration produced by various dorsal root sections.
8. The major pathways in the spinal cord followed by the
primary afferent fibres, as revealed by the Marchi technique.
9. A general consideration of the significance of studies
such as the present, and their possible extension to include
deeper somatic or visceral structures.
Details of the dorsal root sections undertaken have been
provided in an appendix.