Final answer:
The glossopharyngeal nerve triggers saliva secretion from the parotid gland, and this process is facilitated by the otic ganglion in response to taste and other stimuli.
Step-by-step explanation:
The nerve responsible for triggering saliva secretion from the parotid gland is the glossopharyngeal nerve. This nerve carries taste sensations and other stimuli that can initiate the secretion of saliva through a complex process involving the salivary nuclei and autonomic nervous system. The glossopharyngeal nerve's parasympathetic fibers synapse in the otic ganglion, which then projects to the parotid gland, prompting the production of saliva. This physiological response can be triggered by various stimuli, including the taste and smell of food, and is essential for digestion and oral health.