Both areas of the pons are used to: Select one:
A. set the base rate and depth of breathing in a healthy person.
B. ensure that the lungs do not over inflate during breathing.
C. provide forced inspiration or expiration as needed.
D. augment respirations during emotional or physical stress.
The Correct Answer and Explanation is:
The correct answer is D. augment respirations during emotional or physical stress.
Explanation:
The pons, a part of the brainstem, plays a crucial role in the regulation of breathing. It contains several nuclei that work together to fine-tune respiratory functions. Specifically, the pons is divided into two regions: the pontine respiratory group (PRG) and the apneustic center. Both of these areas are primarily responsible for regulating the rate, pattern, and depth of breathing.
- A. Set the base rate and depth of breathing in a healthy person: This statement is incorrect because the primary control of the base rate and depth of breathing is regulated by the medulla oblongata, specifically the dorsal respiratory group (DRG) and the ventral respiratory group (VRG), rather than the pons. The medulla controls the involuntary, automatic breathing processes.
- B. Ensure that the lungs do not overinflate during breathing: This function is primarily controlled by the Hering-Breuer reflex, which involves stretch receptors in the lungs and the vagus nerve. While the pons helps modulate breathing, the reflex to prevent overinflation is more directly related to the medulla and the afferent input from the lungs.
- C. Provide forced inspiration or expiration as needed: Forced inspiration or expiration (such as during strenuous physical activity or speaking) is largely coordinated by the ventral respiratory group (VRG), which is located in the medulla, not the pons. The pons helps with the smooth transition between phases of breathing but does not directly generate forced breaths.
- D. Augment respirations during emotional or physical stress: The pons is involved in adjusting the respiratory rate and pattern, especially during conditions like emotional or physical stress. The pontine respiratory group (PRG) modulates the transitions between inspiration and expiration and increases the rate of breathing during times of stress. This adjustment helps ensure that the body meets the increased oxygen demand during periods of exertion or emotional arousal.
Thus, the pons serves to augment respiratory activity, adjusting it according to physiological needs like stress or exercise, making D the correct choice.