The Glossopharyngeal Nerve is the ninth cranial nerve, primarily responsible for sensory and motor functions in the throat. It plays a key role in taste sensation from the posterior part of the tongue and helps regulate swallowing. Additionally, it contributes to the gag reflex and monitors blood pressure and oxygen levels through its connections to the carotid arteries. This nerve also innervates the parotid gland, stimulating saliva production. It is involved in the autonomic nervous system, influencing functions such as heart rate and digestion. Damage to the glossopharyngeal nerve can lead to difficulties in swallowing and loss of taste.