The term "vocal nerve" is not a specific, officially recognized anatomical term. However, it's commonly used to refer to the nerves responsible for controlling the vocal cords, which are primarily branches of the vagus nerve (cranial nerve X).
Here's a breakdown of the relevant nerves:
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Vagus Nerve (CN X): This is the primary nerve responsible for the motor and sensory functions of the larynx, including the vocal cords.
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Superior Laryngeal Nerve (SLN): A branch of the vagus nerve that further divides into:
- External Laryngeal Nerve (ELN): Primarily responsible for innervating the cricothyroid muscle. This muscle is important for tensing the vocal cords and controlling pitch.
- Internal Laryngeal Nerve (ILN): Provides sensory innervation to the larynx above the vocal folds.
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Inferior Laryngeal Nerve (ILN): This is the terminal branch of the recurrent laryngeal nerve. It provides motor innervation to all the intrinsic muscles of the larynx except the cricothyroid. This includes the muscles responsible for abduction (opening) and adduction (closing) of the vocal cords, which is crucial for phonation (speech). It also carries sensory information from the larynx below the vocal folds.
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In essence, when people refer to the "vocal nerve," they are generally referring to the superior and inferior laryngeal nerves, which are branches of the vagus nerve and control the muscles and sensory functions of the larynx and vocal cords. Damage to these nerves can significantly impair speech and swallowing.
