Question

Diaphragm of man is completely dome shaped during the

• A. End of expiration and beginning of inspiration
• B. Beginning of expiration and end of inspiration
• C. Increased rate of breathing
• D. Decreased rate of breathing

Answer 1

The correct option is A End of expiration and beginning of inspiration

The diaphragm or the thoracic diaphragm is the dome-shaped sheet of muscle and tendon is the main muscle of respiration and has a vital role in the breathing process of human beings. This important anatomical landmark separates the thorax, or chest, from the abdomen. During inhalation, the diaphragm contracts and is drawn inferiorly into the abdominal cavity and the external intercostal muscles between the ribs elevate the anterior rib cage taking the shape of a bucket handle. As air is drawn in the thoracic cavity becomes deeper and larger. While exhaling, the rib cage drops to its resting position and the diaphragm relaxes and elevates to its dome-shaped position in the thorax.