Final answer:
The facial nerve, also referred to as cranial nerve VII, connects with the lingual nerve to supply taste to the anterior two-thirds of the tongue and regulates salivation in the mouth.
Step-by-step explanation:
The nerve that joins the lingual nerve to supply taste to the anterior two-thirds of the tongue and glands for saliva secretion is the facial nerve. The facial nerve, a.k.a. cranial nerve VII, is responsible for gustatory sensations in the anterior two-thirds of the tongue and it also contains parasympathetic fibers that stimulate the submandibular and sublingual glands for saliva production. In contrast, the glossopharyngeal nerve (cranial nerve IX) is primarily responsible for taste in the posterior one-third of the tongue and innervates the parotid gland through the otic ganglion to stimulate saliva secretion. The vagus nerve (cranial nerve X) also plays a role as it connects to taste buds in the extreme posterior of the tongue and participates in the gag reflex.