ATI Pathophysiology Practice Exam 2026 – All-in-One Guide to Master Your Exam Success!

The primary source of acid in the body that affects blood pH levels is carbon dioxide produced from metabolism. During cellular respiration, glucose undergoes metabolic processes to produce energy, resulting in the formation of carbon dioxide as a byproduct. This carbon dioxide dissolves in the blood and reacts with water to form carbonic acid, which then dissociates into bicarbonate and hydrogen ions.

The presence of hydrogen ions is crucial because it directly influences the acidity of the blood; an increase in hydrogen ions lowers the pH, making the blood more acidic. The body has intricate mechanisms, such as respiratory and renal compensation, to regulate the levels of carbon dioxide and thereby maintain acid-base balance, ensuring that blood pH remains within a narrow range of 7.35 to 7.45, which is vital for normal physiological function.

While other listed substances, such as fatty acids, amino acids, and lactic acid, can contribute to acidity under certain conditions, they are not the primary source in the context of daily metabolic processes and the overall regulation of blood pH. For instance, lactic acid primarily accumulates during intense exercise and can contribute to acidosis, but it is not the main continuous source of acid in normal metabolic states.