THE CIRCUMCISION REFERENCE LIBRARY
In a recent paper (Bazett, McGlone and Brocklehurst), data were reported of the temperature changes that accompany temperature sensations, and it was pointed out that inferences as to the mode of stimulation were unwarranted until the end-organs were more surely identified. and their depth established. In that work the skin of the forearm was employed; in the present work the prepuce has been selected, since histologic study of fresh tissue removed at circumcision is possible. The prepuce has the additional advantage that a fold of two layers of skin may be obtained which is less than 2 mm. thick. Consequently, the rate of penetration of heat may be measured and yet the abnormalities introduced by buried thermocouples may be avoided. It is proposed in this paper to present physiologic evidence with a brief account an anatomic data. A more detailed account of the anatomic structures demonstrable in the prepuce will be presented in a later paper.
CIRP note: This paper has a long technical discussion of a histologic study, a physiologic study, and followed by comments. There are tables, graphs and mathematical sections that cannot be satisfactorily transcribed in a text file. For both technical reasons and perceived lack of general interest, CIRP will not present these parts and will only transcribe the conclusions.
1. A brief preliminary description is given of the various sensory organs demonstrable in the prepuce and of their distribution.
2. The spots sensitive to cold in the prepuce and dorsal skin of the penis vary in number from six to twelve per square centimeter. Estimates of their depth from the reaction time and from the rate of thermal transmission suggest a depth of about 0.1 mm. If a thin double fold of skin is obtained, sensitive spots belonging to one layer of skin may be stimulated from either side of the double fold.
3. Histologic studies demonstrate that end-bulbs of the Krause type are distributed in the prepuce, so that their average number is about 15 per square centimeter, and they have a depth of about 0.1 mm. Many of these occur in groups so that several might be identified as a single cold spot. They lie in the arteriovenous region immediately below the papillae of the corium. Their distribution agrees with that of the cold spots.
4. Spots sensitive to warmth in the prepuce and dorsal skin of the penis are few in number (one or rather less per square centimeter). They may be stimulated from either side of a thin double fold of skin. Their depth may be calculated by comparing the reaction times from the two sides with the rates of thermal transmission, and a depth of 0.3 mm. is thus determined. In a few instances the results appear to indicate a greater depth, in the subdermal tissue at about the center of the fold. These sensory spots are commonly definitely related to visible veins, and a spread of thermal changes along the veins is apt to give mild and somewhat diffuse sensations of warmth.
5. Histologic studies demonstrate that Ruffini end-organs have a distribution agreeing fairly well with that of the warm spots. They have a depth of about 0.28 mm. or more and lie in between the second and third venous plexuses of Spaetholtz. Some also occur subdermally,
6. In any square centimeter ruled in square millimeters, sixty-two of the squares gave negative responses to touch stimuli when a stimulus slightly above the threshold value was employed. The threshold stimulus has been from 1.5 to 2. Gm. per millimeter radius of the hair employed (0.12 mm. diameter).
7. Non encapsulated end-bulbs have been identified histologically are are distributed fairly evenly (fifty-two per square centimeter) at a depth of about from 0.03 to 0.04 mm. In a square centimeter the number of square millimeters deficient in this kind of end-bulb agreed well with the average number of squares found to be deficient in touch sensation in the physiologic experiments.
8. Some values are given illustrating the character and degree of thermal transmission across a double fold of skin in this area.
Dr. H. Strughold assisted in some of the experiments.
* Submitted for publication, Aug 6, 1931.
* From the Departments of Physiology, Anatomy and Mathematics, University of Pennsylvania.
* This is the first of a series of three papers on sensation which will be published in this journal.
* The histologic work has been done entirely by R. G. Williams; H. M. Lufkin is responsible for the mathematical analysis to be found on pages 499 to 501; the other two authors are responsible for the physiologic work and for the arguments advanced.
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