Where the highlighted vessel bifurcates there are structures that monitor co2 and o2 concentration in the blood. what are these structures called?

structures that monitor co2 and o2 concentration in the blood called chemoreceptor because it detects chemical inside blood, in this case, CO2 or O2. Those chemoreceptors found in aortic body or carotid vessel. Bifurcated vessel probably is carotid vessel.