Taste sensation from anterior 2/3rd of tongue are carried by
**Core Concept**
The question tests the student's knowledge of the anatomy and physiology of taste sensation in the oral cavity. The anterior 2/3rd of the tongue is responsible for detecting sweet, sour, salty, and bitter tastes, which are mediated by specific taste receptors.
**Why the Correct Answer is Right**
The correct answer is related to the innervation of the tongue by the facial nerve (cranial nerve VII). The chorda tympani branch of the facial nerve carries taste fibers from the anterior 2/3rd of the tongue to the solitary nucleus in the brainstem. This pathway is responsible for transmitting sweet, sour, salty, and bitter taste sensations.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct nerve or pathway responsible for taste sensation from the anterior 2/3rd of the tongue.
**Option B:** This option is incorrect because it does not mention the relevant nerve or pathway, and the glossopharyngeal nerve (cranial nerve IX) is responsible for taste sensation from the posterior 1/3rd of the tongue.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the facial nerve is responsible for taste sensation from the anterior 2/3rd of the tongue, while the glossopharyngeal nerve is responsible for taste sensation from the posterior 1/3rd of the tongue. This knowledge is crucial for diagnosing and managing patients with taste disturbances.
**Correct Answer: A. Facial nerve (cranial nerve VII) via the chorda tympani branch.**