1. A flat structure at the bifurcation (forked or divided into two parts or branches) of the common carotid artery.

It contains cells that respond to changes in oxygen concentration in the blood and to changes in blood pressure.

2. A small structure containing neural tissue at the bifurcation (two branches) of the carotid arteries.

It monitors the pressure and oxygen content of the blood and, therefore, it assists in regulating respiration or breathing.

1. A normal chemical reflex initiated by a decrease in oxygen concentration in the blood and, to a lesser degree, by increased carbon dioxide and hydrogen ion concentrations that act on chemoreceptors at the bifurcation of the common carotid arteries.

The resulting nerve impulses cause the respiratory center in the medulla to increase respiratory activity.

A benign round, firm growth which develops at the bifurcation (two branches) of the common carotid artery or either of the two arteries located in the front of the neck, through which blood from the heart goes to the brain: "A carotid-body tumor may cause dizziness, nausea, and vomiting if it impedes, or hinders, the flow of blood and if pressure is increased in the vascular system, or the circulatory system that transports blood in the body and which is composed of the heart, arteries, capillaries, and the veins."