The experimental studies were performed to observe the characteristics of the myelinated nerve fibers of he etradiaphragmatic branches of phrenic nerves in dog
In the work to be reported five mixed breed Korean dog were used, they were one year old and he body eights were about 12 Kgm. in average with healthy condition.
The specimens (nerve) were taken at the point of 1.5 ㎝ posterior part from the left and right phrenic nerves entrance to the diaphragm, and the dorso-lateral and dorso-medial blanches of phrenic nerves were also taken at the point of 0.5 ㎝ distal part from their branching portion.
The specimens were fixed for 24 hrs. in Flemming’s solution, and embedded in paraffin. The paraffin section were cut at 6 microns and stained with Walter’s modification of Weigert-pal method for the myelinated fibers.
Microphotographs were taken and enlarged into 750 times of the actual size, and the diameter of the photographic images of the myelinated fibers were measured by the scale on the transparent Percepex Plate.
The following conclusions were made:
1. The percentage of distribution of the several intradiaphragmatic branches of phrenic nerves were as follows. Ventral branches were 34.97%, lateral branches were 37.90%, dorsal branches were 27.13%, and the dorsal branches were branched again into dorso-lateral branches(54.22%) and dorso-medial branches(45.78%).
2. The mean value and S.D. of the total numbers of the myelinated nerve fibers at the left ventral branches were 490.80±12, and at the right ventral branches were 486.6±13. Total average cross sectional area on the left ventral branches were 38,000.6±136μ², and the right ventral branches were 37,150.2±1,782μ².
3. The mean value and S.D. of the total numbers of the myelinated nerve fibers at the left lateral blanches were 533.8±8, and at the right lateral branches were 525.6±7. Total average cross sectional area of the left lateral branches were 41,582±1,170μ² , and the right lateral branches were 40,454.8±812μ².
4. The mean value and S.D. of the total numbers of the myelinated nerve fibers at the left dorsal branches were 378.2±14, and at the right dorsal branches were 380.2±8. Total average cross sectional area of the left dorsal branches were 27,771±1,256μ² , and the right dorsal branches were 27,507.2±645μ².
5. The mean value and S.D. of the total numbers of the myelinated fibers at the left dorso-lateral branches were 205.4±15, and at the right dorso-lateral branches were 210.6±17. Total average cross sectional area of the left dorso-lateral branches were 15,354.8±1,519μ² , and the right dorsal branches were 15,887±1,297μ² .
6. The mean value and S.D. of the total numbers of the myelinated nerve fibers at the left dorso-medial branches were 175±14, and at the right torso-medial branches were 176.2±17. Total average cross sectional area of the left dorso-medial branches were 13,037.4±944μ² , and at the right dorso-medial branches were 13,103±1,373μ².
7. The highest frequent distribution of the intradiaphragmatic branches of phrenic nerves were found in the 10-l2μ groups, and they were almost 30% of the total groups
8. The largest fibers diameter were in the 14-l6μ groups, and these were shown the lowest frequent distribution.
9. The largest cross sectional area of the intradiaphragmatic branches of phrenic nerves were found in the 10-l2μ groups.
10. All of the intradiaphragmatic branches of phrenic nerves were unimodal which has a peak in the 10-12μ groups.
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