Symphony of the Endocrine System: The Effects of Yoga Postures
on the Glands
Source: Teaching Asanas, Ananda Marga teacher's manual
Asanas affect every aspect of the human physique;
they balance the glandular secretions, relax and tone up the
muscles and the nervous system, stimulate circulation, stretch
stiff ligaments and tendons, limber joints, massage the internal
organs and calm and concentrate the mind. Gradually as the
body becomes more accustomed to these limbering relaxing exercises,
work becomes an extension of asanas, done at moderate speed
with smooth flowing motions, deep breathing to afford the
body plenty of oxygen, and a calm and controlled mind alert
and responsible to the needs of any situation.
The complex symphony of the body is conducted by a system
of glands known as the endocrine glands. These glands are
often called ductless because they pass their secretions directly
into the blood or lymph, instead of using secretory ducts.
The chemical substances secreted by these glands are called
hormones - chemical messages which act at a distance. Hormones
have a profound effect on all the body's functions, including
growth, digestion, energy levels, heat, sexuality, water and
The pineal body is located directly in the middle of the brain.
It has the largest blood supply for its weight of any organ
in the body. Obviously, some great activity is going on in
this tiny organ, although medical researchers are not sure
exactly what. They do know that the pineal gland secrets melatonin
which may regulate sexual development and serotonin which
seems to be essential for rational thought. The pineal gland
also has optic qualities including sensitivity to light in
higher animals and humans. It actually has a lens and light-sensitive
retina in some lizards. This gland seems to have some importance
in regulating the subtle day-to-day rhythms of the body, including
sleep. It is unique in that it appears to secrete many substances
which have a direct effect on the function of the brain. According
to yoga science, the pineal gland is the master gland of the
body, controlling all the other glands. Secretions from this
gland stimulate all the other lower glands.
The pituitary has been called by medical science the "master
gland." In reality it functions as a relay station for
impulses arising in the hypothalamus, an organ of the brain
which coordinates the nervous system with the glandular system
and controls the body's reaction to emotional states. The
pituitary gland relays the messages from the hypothalamus
to all the endocrine glands of the body. Thus, it may be said
that the pituitary hormones excite the movement of the bowels,
keep the blood vessels toned up and stimulate the kidneys
to do their work. These hormones also control growth and the
development and help to regulate the body's temperature. Improper
secretion of the pituitary gland results in the abnormal growth
of extremely obese people, giants and midgets.
Thyroid and Parathyroid Glands
The thyroid gland in. the neck controls the metabolic rate
of the body, the speed at which the chemical processes of
the body occur. Like a thermostat, it regulates the level
of body heat and energy produced. Among other things, it regulates
growth, repair and waste processes. Any imbalance in the thyroid
gland has serious consequences. Even a slight over secretion
will result in nervous irritability. A slight under secretion
will result in a feeling of fatigue and lethargy. The secretions
from the parathyroid regulate calcium and phosphorus metabolism.
The thymus is a gland located behind the breastbone. It is
very large during childhood but at puberty reduces to one-quarter
of its original size. It is generally agreed that the thymus
exerts a primary role in regulating the immune defenses of
the body against disease, but the details of this mechanism
and other functions of the thymus are unknown.
The adrenal glands, located just on top of the kidneys, help
govern sudden bursts of energy and heat, while stimulating
the twin response of staying to fight or running away (the
fight or flight response). In a crises, when everything depends
on muscular exertion, the brain sends a nervous message to
these glands, which promptly pour their secretions into the
bloodstream. The secretion of adrenaline speeds up the heart
and dilates the blood vessels to the muscles and stimulates
the sweat glands so the body may be cooled. It slows the movements
of the digestive organs and contracts their blood vessels.
It makes the liver shed its stored sugar so the muscles may
have a copious supply of fuel. It stands the hair on end,
dilates the pupils and widens the eyes, so the individual
may be terrifying to look at. It is a chemical S.O.S. A person
whose adrenal glands are not able to secrete sufficient adrenaline
will not be able to respond properly in a crisis. On the other
hand, one whose glands over secrete or secrete inappropriate
The pancreas lies just below the stomach and secretes digestive
enzymes into the small intestine. It secretes insulin, a hormone
which lowers the amount of energy-giving glucose in the blood.
If the pancreas is unable to secrete sufficient amounts of
insulin, blood sugar builds up and diabetes mellitus can result.
Too much insulin on the other hand results in hypoglycemia,
a condition of trembling and weakness.
The gonads (ovaries and testes) primarily govern the sexual
function. In the female the ovaries are located in the abdominal
area and in the male the testes are located in the scrotum.
These glands not only produce sperm and egg cells, but also
secrete androgen (male sex hormones) and estrogen (female
sex hormones). These hormones regulate physical development
of the body and the sexual behavior patterns of the individual.
For example, androgens increase the muscular mass of the body
and seem to induce aggressive behavior. Estrogens increase
fatty padding and may promote passive behavior. Everyone's
body produces androgens and estrogens. It is the proper proportion
of these hormones which balance the personality.
Effect of Asanas
The entire human organism is controlled by the hormones. Every
system, every organ, every tissue, every cell is guided in
its functioning by hormones. The proper growth and functioning
of the various parts of the body is possible only when there
is a balanced secretion of all these hormones. Any imbalance
results in disease.
Asanas balance the hormonal secretions from
the various glands. The twisting and bending positions of
the asanas, held for specific periods of time, place continued
and specific pressure on the various glands of the body, thus
stimulating them in various ways and regulating their secretions.
In the Shoulder Stand, for example, the contraction
of the neck muscles combined with the pressure of the chin
on the chest squeezes blood out of the thyroid and parathyroid
glands. In the Fish Pose which immediately follows the Shoulder
Sstand, the glands are stretched and flooded with blood. The
combination of these two poses effectively massages and stimulates
these two glands, thus greatly improving their functions.
Different asanas are prescribed to strengthen
or regulate the secretion of different glands. For example,
the bow pose and wheel pose affect the adrenal glands. In
this way many common ailments can be alleviated and the body's