36
M. Mukunda Rao
2.3.1 Conscious Control
Conscious control of breathing is common in many forms of meditation, specifically
forms of yoga for example pranayama unlike anapana which is only awareness of
breath. In swimming, cardio fitness, speech or vocal training, one learns to discipline
one’s breathing, initially consciously but later sub-consciously, for purposes other
than life support. Human speech is also dependent on conscious breath control.
2.3.2 Unconscious Control
Unconsciously, breathing is controlled by specialized centres in the brainstem, which
automatically regulate the rate and depth of breathing depending on the body’s needs
at any time. When carbon dioxide levels increase in the blood, it reacts with the water
in blood, producing carbonic acid. Lactic acid produced by anaerobic exercise also
lowers pH. The drop in the blood’s pH stimulates chemoreceptors in the carotid and
aortic bodies in the blood system to send nerve impulses to the respiration centre
in the medulla oblongata and puns in the brain. These, in turn, send nerve impulses
through the phrenic and thoracic nerves to the diaphragm and the intercostal muscles,
increasing the rate of breathing. Even a slight difference in the blood’s normal pH
7.4, could cause death, so this is an important process. This automatic control of
respiration can be impaired in premature babies, the elderly or by drugs and disease
(7).
2.3.3 Breathing Asymmetry
It is interesting to note that in a healthy subject, there is right-left asymmetry of breath
flow, first described by Kayser as early as in 1895 [9]. Breathing is predominant either
through the right nostril or through the left nostril. If not interfered with, the nasal
air flow will exibit rhythmic functioning as the predominance of breathing through
one nostril lasts for 1–2 h after which it shifts to the other nostril. The flow increases
in one side until it reaches a peak, and then it begins to decrease. Finally, most of
the air starts flowing through the opposite nostril. Though this is a natural biological
rhythm, it can be interfered voluntarily or by factors like e.g. shifts in emotional
arousal [10].
M. Mukunda Rao
2.3.1 Conscious Control
Conscious control of breathing is common in many forms of meditation, specifically
forms of yoga for example pranayama unlike anapana which is only awareness of
breath. In swimming, cardio fitness, speech or vocal training, one learns to discipline
one’s breathing, initially consciously but later sub-consciously, for purposes other
than life support. Human speech is also dependent on conscious breath control.
2.3.2 Unconscious Control
Unconsciously, breathing is controlled by specialized centres in the brainstem, which
automatically regulate the rate and depth of breathing depending on the body’s needs
at any time. When carbon dioxide levels increase in the blood, it reacts with the water
in blood, producing carbonic acid. Lactic acid produced by anaerobic exercise also
lowers pH. The drop in the blood’s pH stimulates chemoreceptors in the carotid and
aortic bodies in the blood system to send nerve impulses to the respiration centre
in the medulla oblongata and puns in the brain. These, in turn, send nerve impulses
through the phrenic and thoracic nerves to the diaphragm and the intercostal muscles,
increasing the rate of breathing. Even a slight difference in the blood’s normal pH
7.4, could cause death, so this is an important process. This automatic control of
respiration can be impaired in premature babies, the elderly or by drugs and disease
(7).
2.3.3 Breathing Asymmetry
It is interesting to note that in a healthy subject, there is right-left asymmetry of breath
flow, first described by Kayser as early as in 1895 [9]. Breathing is predominant either
through the right nostril or through the left nostril. If not interfered with, the nasal
air flow will exibit rhythmic functioning as the predominance of breathing through
one nostril lasts for 1–2 h after which it shifts to the other nostril. The flow increases
in one side until it reaches a peak, and then it begins to decrease. Finally, most of
the air starts flowing through the opposite nostril. Though this is a natural biological
rhythm, it can be interfered voluntarily or by factors like e.g. shifts in emotional
arousal [10].