4. Function of the Diaphragm and Abdominal Respiration
The diaphragm is a thick dome-shaped musculomembranous partition separating the abdominal cavity containing the stomach, intestines, and liver and the thoracic cavity containing the lungs and heart. In a deep breath, the diaphragm hangs over the abdominal cavity.
Breathing can be done -- two ways thoracically by constrict or expanding the chest and abdominally by constricting or expanding the abdomen.
The diaphragm does not move much in thoracic respiration, but descends when air is drawn in during abdominal respiration, expanding the lungs to deliver air to all segments. Exhalation raises the diaphragm to help the lungs contract and expel more air.
Abdominal respiration plays a very important role in esophageal speech and is one of the keys to its success.
