Final answer:
Peripheral chemoreceptors detect a decline in blood pH and stimulate an increase in ventilation to restore pH levels by removing excess carbon dioxide, which is converted to acid in the blood.
Step-by-step explanation:
When pH levels decline, indicating an increase in hydrogen ion concentration and thus more acidic conditions, peripheral chemoreceptors located in the aortic arch and carotid arteries are stimulated. These receptors detect changes in the arterial blood's pH and send signals to increase ventilation as a response. The rise in ventilation rate helps to excrete more carbon dioxide from the body, which is converted into carbonic acid in the blood. Eliminating carbon dioxide reduces the concentration of hydrogen ions, consequently leading to an increase in pH back towards normal levels. The objective of this adjustment is to maintain homeostasis by balancing the pH of the blood, essential for proper cellular function.
In more detailed terms, as carbon dioxide levels rise in the blood due to metabolic activity, it leads to an increase in hydrogen ions, causing a drop in pH. This drop is detected by chemoreceptors that send signals to increase the respiration rate. Faster breathing expels more carbon dioxide, which in turn helps lower the hydrogen ion concentration and raise the blood pH. Hence, the respiratory and cardiovascular systems work closely together to ensure sufficient oxygen supply to cells and removal of carbon dioxide, in accordance with changing metabolic demands.