Final answer:
The carotid body sends information to the brain via the glossopharyngeal nerve, which is cranial nerve IX.
Step-by-step explanation:
The carotid body sends information to the brain via the glossopharyngeal nerve, which is also known as cranial nerve IX. Baroreceptors within the carotid bodies have axons that travel through this nerve. When these baroreceptors detect changes in blood pressure, they send signals through the glossopharyngeal nerve to the brain to regulate cardiovascular function. The common carotid artery is a vital blood vessel that branches off the aorta or brachiocephalic artery and supplies blood to the head and neck. This artery contains the carotid sinus, which is innervated by the glossopharyngeal nerve and plays a crucial role in the reflexive regulation of blood pressure.