Question

Which of the following is false? Unselected Under normal conditions, blood PO2 affects breathing only indirectly. Unselected Changes in arterial pH resulting from CO2 retention or metabolic factors act through the peripheral chemoreceptors. Unselected When arterial PO2 falls below 60 mm Hg, it becomes the major stimulus for respiration. Unselected Oxygen levels are the primary stimulant of respiration.

Answer 1

Answer:

The sentence that says: Blood PO2 affects respiration only indirectly, IT IS FALSE, since the partial pressure of oxygen gas together with carbon dioxide are factors that DIRECTLY affect respiration.

The sentence that says: Unselected changes in arterial pH as a result of CO2 retention or metabolic factors act through peripheral chemoreceptors. It is FALSE, since the central chemoreceptors together with the peripheral ones can detect the metabolic acidosis generated by the CO2 retention, this is how the CNS receptors capture the CO2 that crosses the blood-brain barrier and stimulates hyperventilation to compensate for this phenomenon and increase the plasma concentrations of partial oxygen pressures.

The sentence that says: in selecting When arterial PO2 falls below 60 mm Hg, it becomes the main stimulus for breathing, IT IS FALSE, since it not only encourages ventilation to promote oxygenation but also activates the renin-angiotensin-aldosterone in order to recover blood volume and thus achieve adequate blood pressure.

In addition, hypovolemia triggers tachycardia and weakening symptoms, which is why the drop in blood pressure is not the main stimulus for breathing.

Explanation:

Breathing is promoted by muscle contraction, medium and high temperatures (that is, in hot or hot climates), partial concentrations of oxygen and carbon dioxide both in the atmosphere and in our blood, and in situations of systemic imbalances such as metabolic acidosis or alkalosis.