Final answer:
The facial nerve is responsible for the sense of taste in the anterior two-thirds of the tongue and provides oropharyngeal sensation. It works with the gustatory system and is tested using various taste stimuli, with its role supplemented by the glossopharyngeal and vagus nerves in the oral cavity.
Step-by-step explanation:
The facial nerve is responsible for receiving the sense of taste from the anterior two-thirds of the tongue and provides sensation to the oropharynx. It also plays a role in salivation and the gag reflex, which is mediated by the glossopharyngeal and vagus nerves. Facial and glossopharyngeal nerves are key for conveying gustatory stimulation to the brain.
The gustatory cells, when activated by taste molecules, release neurotransmitters that stimulate the dendrites of sensory neurons. For the anterior two-thirds of the tongue, this is done through the facial nerve. Contraction of muscles in the pharynx for the gag reflex, a role associated with the vagus nerve, complements the sensation functions of these cranial nerves.