Carotid bodies are small clusters of chemoreceptor cells located near the bifurcation of the carotid arteries in the neck. They play a crucial role in monitoring the levels of oxygen and carbon dioxide in the blood. When oxygen levels drop, the carotid bodies send signals to the brain to increase breathing rate and improve oxygen intake. These structures are part of the body's respiratory system and help maintain homeostasis. They respond to changes in blood chemistry, ensuring that the body can adapt to varying levels of physical activity or environmental conditions. This function is vital for overall health and well-being.