The branch

Branch

A branch or tree branch is a woody structural member connected to but not part of the central trunk of a tree...

 of the glossopharyngeal nerve

Glossopharyngeal nerve

The glossopharyngeal nerve is the ninth of twelve pairs of cranial nerves . It exits the brainstem out from the sides of the upper medulla, just rostral to the vagus nerve...

 to the carotid sinus

Carotid sinus

In human anatomy, the carotid sinus is a localized dilation of the internal carotid artery at its origin, the common carotid artery.-Functions:...

 and the carotid body

Carotid body

The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork of the carotid artery ....

is the nerve

Nerve

A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...

 that runs downwards anterior to the internal carotid artery communicates with the vagus and sympathetic then divides in the angle of bifurcation of the common carotid artery to supply the carotid body and carotid sinus. It carries impulses from the baroreceptors in the carotid sinus (to help maintain a more consistent blood pressure

Blood pressure

Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

) and from chemoreceptors in the carotid body.

It is also known as "Hering's nerve".