What type of bodies send signals to the medulla via vagus nerves?

The aortic bodies are specialized chemoreceptors located in the aortic arch. They play a critical role in monitoring the levels of oxygen and carbon dioxide in the blood, as well as the pH of the blood. When they detect changes in these parameters, such as low oxygen levels or increased carbon dioxide, they send signals to the medulla oblongata through the vagus nerves. This communication is essential for the regulation of respiratory and cardiovascular functions, allowing the body to respond appropriately to shifts in blood chemistry.

In contrast, carotid bodies, while also chemoreceptors, primarily communicate with the brainstem via the glossopharyngeal nerve, not the vagus nerve. Central chemoreceptors, located in the brain, respond to changes in the cerebrospinal fluid rather than blood chemistry directly, and neural pathways encompass a broader range of neural structures and functions not limited to chemoreceptive signaling. Thus, the function of the aortic bodies in sending signals specifically through the vagus nerves is what makes this choice the correct answer.