Question

The dorsal respiratory group is primarily responsible for?

1) motor control of the inspiratory and expiratory muscles.
2) decreasing the respiratory rate when the blood pH is above 7.45.
3) terminating inspiration in order to prevent pulmonary overexpansion.
4) initiating respiration based on information received from the chemoreceptors.

Answer 1

The dorsal respiratory group (DRG) is responsible for initiating and regulating the basic rhythm of respiration by stimulating the diaphragm and intercostal muscles to contract for inspiration and allowing them to relax for expiration. (option 4)

Step-by-step explanation:

The dorsal respiratory group (DRG) is a region of the medulla oblongata that is primarily responsible for the initiation and regulation of the basic rhythm of respiration. The DRG achieves this by stimulating the contraction of the diaphragm and intercostal muscles which results in inspiration. When the activity of the DRG ceases, these muscles relax, leading to expiration. Therefore, the correct answer to what the dorsal respiratory group is primarily responsible for is initiating respiration based on information received from the chemoreceptors, which monitor the chemical composition of the blood and provide feedback to maintain respiratory homeostasis.

The dorsal respiratory group's principal function is to initiate respiration in response to chemoreceptor feedback, showcasing its pivotal role in maintaining respiratory homeostasis.