Structure of the diaphragm

The diaphragm is a great muscle. It's a vital pump in the body and it has so many different functions. It's the primary muscle of breathing, so it's the main muscle we use. It's also involved in many other functional activities, such as spinal stability, digestion, and lymphatic control. Its local anatomy is a curved muscle with a central tendon, and it looks a bit like a parachute or a mushroom or a jellyfish. It's supplied by C3, C4 and C5 and it has the vena cava, oesophagus and the aortic hiatus passing through it. It has attachments along the lower edge of the six ribs, and it also has arcuate ligaments which attach to the body of the vertebra one, two and three.

If you want to learn more about this topic, you can watch Scott Peirce's lecture here:

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What is its function?

During relaxed breathing, the diaphragm moves in a descending wave like fashion, gently pulling down and compressing on the stomach, the liver, and the abdominal organs, and then relaxing and coming back up. We can also think about the diaphragm having a thickness much like the bicep, and we can examine this quality and look at how the diaphragm sits on the rib wall in the zone of that position. How thick the diaphragm is correlates directly with the strength of inspiration and wasting of the diaphragm is actually, pretty common clinically. The Intercostals are important, as they are needed to stabilize and expand the ribcage during inhalation and diaphragm its descent. The posterior portions of the diaphragm are important because they stabilize the ribcage during sleep. They are multilayered.

3 things you didn’t know about the diaphragm

1. The diaphragm and the pelvic floor have a special ‘piston’ relationship.

The pelvic floor have a huge relationship with breathing and in particular,the diaphragm. In normal breathing, we see this descent, like a piston of both the diaphragm and the pelvic floor in an unloaded position, and it should really return to a good resting level. Considering this, dysfunctional breathing may add to the load put on dysfunctional pelvic floor muscles as well. The pelvic floor muscles contribute to both postural and respiratory functions.

2. The diaphragm aids vascular tone and fluid recycling

The diaphragm also aids vascular tone and fluid recycling through generating intra-abdominal pressure and changing pressure fluctuations in the gut. More impressively, the diaphragm has a lymphatic system which actually lies in between sections of the muscle, and that will rapidly drain the abdominal cavity of extra fluid as well.

3. The diaphragm is important in digestion

The diaphragm is also very important in reflux and digestion, with studies showing a reduction in gastroesophageal reflux symptoms. With diaphragmatic breathing we know there is a complex relationship with low back pain, disorders of the gut, and disorders of breathing as well. Thus, one system seems to be able to influence the other in back and forth manner.

If you want to learn more about this topic, you can watch Scott Peirce's lecture here:

Click here

SOURCES:

1. ‘Functional anatomy and physiology of breathing’ lecture by Scott Peirce