Earache in Acute tonsillitis is due to involvement of the following nerve:
**Core Concept**
The underlying principle being tested is the anatomical connection between the tonsils and the nerves supplying the ear. **Referred pain** is a key concept here, where pain from one location is perceived in another. The **glossopharyngeal nerve** plays a crucial role in this scenario.
**Why the Correct Answer is Right**
The correct answer involves the nerve responsible for transmitting pain from the tonsils to the ear. The **glossopharyngeal nerve (CN IX)** is involved in swallowing and also provides sensory innervation to the tonsils and the middle ear. When the tonsils are inflamed, as in acute tonsillitis, the pain can be referred to the ear via the **glossopharyngeal nerve**.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not specified, but typically, other nerves like the trigeminal nerve are involved in facial pain, not specifically earache from tonsillitis.
**Option B:** Incorrect as it is not provided, but usually, the vagus nerve, while important, is not directly responsible for referred ear pain from tonsillitis.
**Option C:** Incorrect because, although not specified, nerves like the facial nerve are more related to facial expressions and taste, rather than pain referral from the tonsils.
**Option D:** Incorrect as it is not given, but generally, other nerves do not have the specific connection between the tonsils and the ear.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the **glossopharyngeal nerve** is responsible for the referred pain to the ear in cases of acute tonsillitis. This is a classic example of referred pain and is crucial for diagnosing and managing patients with earache and tonsillitis.
**Correct Answer:** Correct Answer: C. Glossopharyngeal nerve.