Final answer:
Respiratory gases travel from the lungs through the alveoli during pulmonary gas exchange, to body tissues such as the big toe by the systemic circulation via arteries and back to the heart through veins, then return to the lungs for exhalation. Hyperventilation can cause alkalosis, an excessive increase in blood pH level.
Step-by-step explanation:
Path of Respiratory Gases
The path of respiratory gases from inhaling air to reaching the tissues of your big toe and being exhaled again involves both the pulmonary and systemic circuits. It starts with inhalation where air enters through the nose or mouth and travels down the trachea to the lungs, filling the alveoli. Here, the pulmonary gas exchange occurs, where oxygen diffuses into the blood and carbon dioxide diffuses out. The oxygen-rich blood is then transported through the pulmonary veins into the left atrium, through the mitral valve to the left ventricle, and out via the aorta into the systemic circulation.
From the aorta, the blood travels through ever-smaller arteries until it reaches the capillaries in the tissues of the big toe, where the peripheral gas exchange takes place. Oxygen is delivered to the tissue cells, and carbon dioxide waste is picked up. The deoxygenated blood returns to the heart through the venous system, entering the right atrium through the vena cava, passing through the tricuspid valve to the right ventricle, and then being pumped into the pulmonary arteries going back to the lungs.
Regarding the phenomenon of hyperventilation, breathing too fast can lead to excessive loss of carbon dioxide causing alkalosis, a state where the blood becomes too basic. This disrupts the acid-base balance in the blood, which can have various physiological effects, including lightheadedness.