MCQ IN MEDICINE

Detailed explanation-1: -Rhythmic breathing (normal, quiet breathing at rest or during sleep) is initiated by the respiratory centre in the medulla oblongata of the brainstem. This centre has two groups of neurones: a ventral group and a dorsal group.

Detailed explanation-2: -To initiate breathing, the dorsal respiratory group sends impulses through the phrenic nerve towards the diaphragm and through the intercostal nerves towards the external intercostal muscles. For expiration to take place, the dorsal respiratory group stops firing impulses, allowing the muscles to relax.

Detailed explanation-3: -Respiratory Structure The medulla and the pons are the major brain centers that affect respiration. An increased concentration of carbon dioxide normally stimulates the body’s respiratory center in the medulla, and to a lesser extent, by decreased levels of oxygen in arterial blood.