Understanding the anatomical map of structures such as the phrenic nerve is vital for medical treatments. G.S. Muller Botha mapped the phrenic nerve and described her findings in The Anatomy of the Phrenic Nerve Termination and the Motor Innervation of the Diaphragm. Sleep apnea is a common disorder caused by under stimulation of the diaphragm from the phrenic nerve, O. Oldenburg and team described alternative treatments for the apnea in Effects of unilateral phrenic nerve stimulation on tidal volume. Lastly, Huemer and associates described a common procedure that causes damage to the phrenic nerve due to its anatomical positioning in Mapping of the Left-Sided Phrenic Nerve Course in Patients Undergoing Left Atrial Catheter Ablations.
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It was observed in some cases that the nerve seemed to lie more anteriorly compared to the majority, but Botha noted that this would not contribute to any practical difference in function. The left phrenic nerve was described as running anterior and lateral upon descent as it passed superficially over the pericardial base. Both the left and right phrenic nerves were observed to divide into two to seven branches as they approached the diaphragm. This observation was in contradiction to the previously conceived notion that there were strictly three branches per nerve. Botha noted at this point that the branches of nerve fibers were heavily insulated by fat deposits. Furthermore, Botha described that the long filaments that branch off posteriorly supply the costovertebral arches and innervate the crural fibers located on the right side of the hiatus, though it was noted that there are no fibers coming from the particular branch that supplied the left side. The left side was observed to be supplied by the postero-medial branching. This branch innervated through the diaphragm and then continued to run along the inferior surface of the diaphragm (Botha …show more content…
Nerve stimulation experiments were run on the animals. The experiments showed that when the phrenic nerve was locally stimulated, the diaphragm contracted ipsilateral (Botha 53). The studies all led Botha to conclude that the phrenic nerve is the sole motor innervation of the diaphragm. This determination was said to be logical by Botha, since the diaphragm must contract in a synchronized manner, if the innervation of the muscle was coming from multiple sources, the synchronization would be much more complex than necessary (Botha
It was observed in some cases that the nerve seemed to lie more anteriorly compared to the majority, but Botha noted that this would not contribute to any practical difference in function. The left phrenic nerve was described as running anterior and lateral upon descent as it passed superficially over the pericardial base. Both the left and right phrenic nerves were observed to divide into two to seven branches as they approached the diaphragm. This observation was in contradiction to the previously conceived notion that there were strictly three branches per nerve. Botha noted at this point that the branches of nerve fibers were heavily insulated by fat deposits. Furthermore, Botha described that the long filaments that branch off posteriorly supply the costovertebral arches and innervate the crural fibers located on the right side of the hiatus, though it was noted that there are no fibers coming from the particular branch that supplied the left side. The left side was observed to be supplied by the postero-medial branching. This branch innervated through the diaphragm and then continued to run along the inferior surface of the diaphragm (Botha …show more content…
Nerve stimulation experiments were run on the animals. The experiments showed that when the phrenic nerve was locally stimulated, the diaphragm contracted ipsilateral (Botha 53). The studies all led Botha to conclude that the phrenic nerve is the sole motor innervation of the diaphragm. This determination was said to be logical by Botha, since the diaphragm must contract in a synchronized manner, if the innervation of the muscle was coming from multiple sources, the synchronization would be much more complex than necessary (Botha