The Diaphragm and Heartburn

I used to go very regularly to Yoga which I found very beneficial and I still recommend the activity to my patients. Unfortunately with time at a premium these days, yoga has gone the way of many other things for me. Normally yoga teachers place much emphasis upon ‘breathing’ and the use of the thoracic diaphragm, the partition between the thorax and abdomen. The diaphragm plays an important role in respiration; as it contracts and flattens, the volume of the cavity increases, therefore air is drawn into the thoracic cavity…. and so we breathe.  Other functions include contracting in sneezes, coughing called the ‘Valsalva manoeuvre’, Vomiting, Defecating, Urinating and preventing acid reflux from the stomach. The reason for yoga? Well if you have a properly functioning and strong abdominal wall, pelvic floor and thoracic diaphragm, most things in the region work more effectively and well as the lumbar spine.

The diaphragm is dome shaped and attaches onto the internal chest and abdominal wall, the central part of the dome is a fibrous/ tendonous sheet the outer parts are more muscular and these are what contract in breathing. As you might anticipate the body has certain vessels which must pass through the diaphragm such as the Inferior Vena Cava which returns blood from the abdomen and lower body to the heart, in the opposite direction we have the Aorta taking oxygenated blood from heart to lower body. The other big vessel is the Oesophagus passing into the Stomach from above and some other neurological structures; basically it’s got quite a few holes in it!   

The diaphragm has a nerve supply from the neck C3, C4 and C5 level via the phrenic nerve, hence when some people fracture their neck high up they can die from asphyxiation well before the global paralysis of other skeletal muscles affects them. The old saying is ‘C3,4,5 keeps the diaphragm alive’.

Hernias are where there is the pushing out or through of one structure or organ, from where is should be, to where it shouldn’t be, usually through and anatomical barrier such as a diaphragm. In adults hiatus hernias are fairly common and are caused by the bottom of the oesophagus or the top of the stomach bulging through the diaphragm into the chest cavity. This can be very serious, leading to damage of the oesophagus as the stomach’s contents, largely hydrochloric acid ‘burn’ the internal lining of the oesophagus inducing in some cases pre-cancerous cell changes as well as heartburn and gastric pain.