Which nerve communicates signals from the carotid bodies to the medulla?

The glossopharyngeal nerve is responsible for transmitting sensory information from the carotid bodies, which are important chemoreceptors located near the bifurcation of the carotid arteries. These bodies monitor blood chemistry, specifically the levels of oxygen and carbon dioxide, and send this information to the medulla oblongata, which plays a crucial role in the regulation of respiration and cardiovascular function.

When blood oxygen levels drop or carbon dioxide levels rise, the signals from the carotid bodies through the glossopharyngeal nerve help to initiate reflexive responses to restore proper gas exchange, such as adjusting the breathing rate and modifying heart rate. This communication is essential for homeostatic control of respiratory and circulatory systems, making the glossopharyngeal nerve vital for maintaining physiological balance.