Deep surface of hyoglossus is related to
**Core Concept**
The hyoglossus muscle is a key muscle in the tongue, involved in its movement and function. The deep surface of the hyoglossus muscle forms a fascial relationship with the underlying structures in the neck, particularly with the lingual artery and nerve.
**Why the Correct Answer is Right**
The deep surface of the hyoglossus muscle is related to the **lingual artery**. This is because the lingual artery, a branch of the external carotid artery, passes over the deep surface of the hyoglossus muscle as it ascends to supply the tongue. The lingual nerve, a branch of the mandibular division of the trigeminal nerve, also lies deep to the hyoglossus muscle and is closely associated with the lingual artery.
**Why Each Wrong Option is Incorrect**
* **Option A:** The hyoglossus muscle is not related to the **stylohyoid ligament**, which is actually related to the styloglossus muscle.
* **Option B:** The deep surface of the hyoglossus muscle is not related to the **hypoglossal nerve**, which is actually a nerve that innervates the tongue muscles, including the hyoglossus muscle, but does not form a fascial relationship with it.
* **Option C:** The deep surface of the hyoglossus muscle is not related to the **common carotid artery**, which is a larger artery that lies anterior to the hyoglossus muscle.
**Clinical Pearl / High-Yield Fact**
In surgical procedures involving the tongue or the neck, knowledge of the fascial relationships between the hyoglossus muscle and the lingual artery is crucial to avoid damage to these vital structures.
**Correct Answer: D. Lingual artery.**