Carotid canal the cranium, as well as the carotid plexus of nerves traveling on the artery. Sympathetics to the head from the superior cervical ganglion also pass through the carotid canal. They have several motor functions: raise the eyelid (superior tarsal muscle), dilate pupil, innervate sweat glands of face and scalp and constricts blood vessels in the head. Carotid canal The carotid canal is the passageway in the temporal bone through which the internal carotid artery enters the middle cranial fossa from the neck. The canal starts on the inferior surface of the temporal bone at the external opening of the carotid
Carotid body central chemoreceptors in the medulla oblongata that are primarily sensitive to changes in pH and P (a decrease in pH and an increase in P). The carotid body chemoreceptors are also sensitive to pH and P, but only secondarily. More specifically, the sensitivity of carotid body chemoreceptors to decreased P is greater when pH is decreased and P is increased. The output of the carotid bodies is low at an oxygen partial pressure above about 100mmHg (13,3 kPa) (at normal physiological pH), but below 60mmHg the activity of the type I (glomus) cells increases rapidly due to a decrease in