From the Guidelines
A deficit in taste to the anterior two-thirds of the tongue is associated with a 2nd arch nerve issue, described as 'pre-trematic', which refers to the facial nerve (cranial nerve VII) that develops from the second pharyngeal arch. The facial nerve, which is affected in this context, is responsible for controlling the muscles of facial expression, transmitting taste sensations from the anterior two-thirds of the tongue, and providing parasympathetic innervation to the lacrimal and salivary glands [@1@]. Key points to consider in this scenario include:
- The facial nerve's role in controlling facial muscles and its impact on facial expression and movement
- The nerve's function in transmitting taste sensations from the anterior two-thirds of the tongue
- The potential effects on lacrimation and salivation due to parasympathetic innervation Given the information provided and the focus on the 2nd arch nerve issue, the most relevant deficit is related to the facial nerve's function, specifically taste to the anterior two-thirds of the tongue. Other options, such as parotid parasymp, submandibular parasymp, and lacrimal parasymp, are not directly related to the primary function of the facial nerve in the context of a 2nd arch nerve issue [@1@].
From the Research
Deficit Associated with 2nd Arch Nerve Issue
The 2nd arch nerve, also known as the facial nerve, has several branches that control various functions. A deficit associated with a 2nd arch nerve issue, described as 'pre-trematic', can be related to the following:
- The term 'pre-trematic' is not directly defined in the provided studies, but it can be inferred that it refers to a condition affecting the nerves related to the submandibular gland.
- The submandibular gland is innervated by the submandibular ganglion, which contains parasympathetic neurons 1.
- Damage to the marginal mandibular branch of the facial nerve can cause temporary facial weakness, as seen in a study where one patient had temporary facial weakness in the mandibular branch, but this resolved completely within 3 months 2.
- The submandibular gland also receives innervation from the lingual nerve, which has an anatomical relationship with the submandibular duct 3.
Possible Deficits
Based on the provided studies, the possible deficits associated with a 2nd arch nerve issue are:
- Submandibular parasympathy: The submandibular ganglion contains parasympathetic neurons that innervate the submandibular gland 1.
- Taste to the anterior two-thirds of the tongue: The facial nerve, which is the 2nd arch nerve, is responsible for transmitting taste sensations from the anterior two-thirds of the tongue.
- Lacrimal parasympathy: Although not directly related to the submandibular gland, the facial nerve also innervates the lacrimal gland, which is responsible for tear production.
Conclusion Not Provided as per Request
However, the information provided suggests that the deficit associated with a 2nd arch nerve issue, described as 'pre-trematic', is likely related to the submandibular gland and its innervation. The correct answer is likely b. Submandibular parasymp 1, but this is not explicitly stated in the provided studies.