Celebrating The First International Day of Yoga

THE DIAPHRAGM
Inhalation
During inhalation
the diaphragm
contracts
and moves
downwards.
Exhalation
During exhalation
it relaxes and
moves back up.
© Dorling Kindersley Limited
Abdominal breathing is also known as deep
diaphragmatic breathing and it is the diaphragm
that takes centre stage here. What exactly is this
muscle and what does it do?
The diaphragm has been variously described
as a muscle shaped like a double dome, a parachute, a jellyfish,
a cupola and so on. Just like other muscles in the body it is
fibrous, non-rigid, contracts and stretches, and because of its supple -
ness takes the form of the organs with which it comes into
contact. At the top of the “dome” the tissue contains a mass
of collagen fibres which together make up the central tendon.
Where is the diaphragm in the body?
It lies between the thoracic (chest) cavity and the abdominal
cavity. In fact it separates these two cavities and at the same
time connects them to each other. One can think of the
diaphragm as acting like double-sided tape. On the upper
side – the thoracic cavity or thorax – the lungs are attached via
the pleura, (a thin sheet of tissue surrounding the lungs) and
the heart via the pericardium (a sac of smooth membrane
enclosing the heart). On the lower side – the abdominal
cavity – the diaphragm attaches to the stomach and the liver
via the peritoneum, (a membrane that covers many of the
abdominal organs). The muscle is also in direct contact with the
kidneys, spleen, pancreas and parts of the large intestine.
At its base the diaphragm is attached to the skeleton at the
lower rib cage and to the spine in the lumbar region, around
waist level. The top of the muscle (the central tendon) reaches
the height of the fourth or fifth rib.
What exactly does the diaphragm do and
what is its role in the breathing mechanism?
Most of us believe that the breathing mechanism starts with
the inhalation of air. This is not accurate. Initially the body
registers its need for air and nerve impulses pass to the
diaphragm instructing it to contract. When the diaphragm
contracts it loses its bowl-like shape and flattens moving
downwards, pulling the lungs in the same direction (remember
the lungs are attached to the diaphragm) creating a vacuum in
the lungs. In order to maintain equal pressure inside the lungs
and outside of the body, inhalation is initiated. As the lungs
expand with the intake of breath they push down on the
diaphragm. As the diaphragm moves downward it exerts
pressure on the abdominal organs. These are unable to compress
and so balloon outwards, giving the impression that it is the
abdomen that is “breathing”. If the stomach is full or the lungs
are not elastic enough the inhalation will be inhibited.
In exhalation the relaxation of the respiratory muscles
decreases the chest cavity, deflates the lungs and the top of the
diaphragm (central tendon) is drawn upward by the contraction.
The relaxation of the diaphragm back to its dome shape allows
the abdomen to return to its original position.
The advantages of abdominal breathing are many and it is
these that make the diaphragm such an amazing muscle. Abdominal
breathing is the most efficient method for achieving maximum
movement of air (both inhalation and exhalation) with the least
expenditure of muscle energy. The diaphragm moves internal
organs, which in the case of the abdominal organs helps to
eliminate constipation. Tension in the shoulders is reduced as these
are not used in the breathing process. By the movement of the
diaphragm over the aorta and vena cava more blood is brought
to the heart increasing circulation in the heart and around the
body. The lymphatic system is stimulated by the movement of the
diaphragm increasing the strength of immunity within the body.
Abdominal breathing is not just “breathing”
Its advantages are far reaching and for these we can thank
the diaphragm for its tireless work!! n
Swami Rajeshwarananda is the director of the Sivananda
Yoga Vedanta Centre in Rome. email: swamirajesh@sivananda.org
YOGALife |Autumn/Winter 2015
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