Biochemistry (Pre-Med) Major
Physical and Biological Sciences Category
My name is Shelby Kuhnert, and I am a senior here at MSSU majoring in Biochemistry (Pre-med). When I graduate in May, I will begin working at Freeman as an Intraoperative Neuromonitoring Technologist. I am really looking forward to this opportunity to gain clinical experience and learn more about neuroscience. In the future, I would like to go to medical school, with the goal of becoming a neurosurgeon. My passion for neuroanatomy and physiology is what led to my interest in research about the nervous system.
INTRODUCTION. The phrenic nerve is a mixed nerve that arises from the anterior primary rami of C3-C5 bilaterally and is the main motor supply to the diaphragm. The diaphragm muscle has a multifaceted impact on body functions- including breathing, visceral health, CSF flow, and emotional regulation. Previous studies reveal that both phrenic nerves lack the sympathetic component at the level of the diaphragm but recover it in the abdominal region from celiac plexus communication. The aim of the current study was to analyze the constitution of branches, targeting the presence of sympathetic fibers. METHODS. Right phrenic nerves from six formalin-preserved adult human cadavers were dissected at the MSSU cadaver lab. Samples were collected at the root of the neck, thoracic region where the phrenic nerve splits into two main trunks and identified abdominal communicating branches. All sections were prepared using H&E and Luxol Fast Blue staining. Antibody staining for tyrosine hydroxylase was used to determine the presence of catecholaminergic fibers. The results were processed with ImageJ. RESULTS. Lack of communication was observed between the cervical phrenic nerve and sympathetic cervical ganglia. No TH activity was detected in the cervical region. TH positive fibers were observed in the trunk that travels below the diaphragm and abdominal communicating branches. A branch to IVC was identified that contained TH-positive fibers. CONCLUSION. Understanding the sympathetic component of the phrenic nerve could elucidate the impact of proper respiration on overall health.