Autonomic innervations in the middle ear and pharynx

Area of Science:

• Neuroscience
• Anatomy
• Head and Neck Surgery

Background:

• The autonomic nervous system plays a crucial role in regulating various physiological functions.
• Understanding the specific innervation patterns of the head and neck structures is essential for clinical applications.

Purpose of the Study:

• To investigate the autonomic innervation of the middle ear and pharyngeal mucosa.
• To identify the specific autonomic ganglia contributing to this innervation.

Main Methods:

• Retrograde labeling of autonomic ganglia using horseradish peroxidase (HRP).
• Examination of sympathetic ganglia: superior cervical ganglion (SCG), middle cervical ganglion (MCG), and stellate ganglion (StG).
• Examination of parasympathetic ganglia: pterygopalatine ganglion (PpG) and otic ganglion (OtG).

Main Results:

• Sympathetic innervation of the middle ear mucosa originates from the ipsilateral SCG.
• Parasympathetic innervation of the middle ear mucosa originates from the ipsilateral PpG.
• The epipharynx receives sympathetic innervation from the ipsilateral SCG and parasympathetic innervation bilaterally from the PpG.
• The mesopharynx and hypopharynx receive bilateral sympathetic innervation from the SCG, MCG, and StG, with the hypopharynx showing greater innervation from the MCG and StG.

Conclusions:

• The study elucidates the specific pathways of autonomic innervation to the middle ear and pharyngeal regions.
• Identified the SCG and PpG as key contributors to the innervation of the middle ear and epipharynx.
• Detailed sympathetic innervation patterns for the mesopharynx and hypopharynx, highlighting regional variations.