Master Blood Acid-Base Control with Picmonic for Medicine

The human body has certain physiological mechanisms designed at maintaining physiological conditions. For example, the body regulates the pH of blood using multiple physiological systems. This Picmonic will focus on acidemia and how the body responds to it. Acidemia is a blood pH <7.35 and results from either excess CO2 levels (respiratory acidosis) or excess hydrogen levels (metabolic acidosis). Alkalosis is the opposite, with pH >7.35 and is caused by either a lack of CO2 (respiratory alkalosis) or an excess of bicarbonate (metabolic alkalosis). The lungs and kidneys can control this balance through their regulation of CO2 levels and hydrogen/bicarbonate levels, respectively. The lungs are controlled by medullary chemoreceptors which detects blood pH and sends inputs to the diaphragm and external intercostal muscles to respond accordingly. In response to acidosis, ventilation rate increases resulting in CO2 exhalation and therefore an increase in pH. The kidneys alter acid/base status by their handling of both hydrogen and bicarbonate. In acidosis, the kidneys increase bicarbonate reabsorption into the blood, causing an increase in pH. Finally, the kidney can excrete hydrogen ions into the urine, which results in less acidic blood and therefore an elevated blood pH.