Deep breathing lessens the risks associated with internal carbon dioxide levels because the inhalation and exhalation process is longer. Retaining carbon dioxide in the blood makes it more acidic and causes a dangerous drop in pH. Slow uptake of air ensures that oxygen is able to bind to the blood, and slow release guarantees that carbon dioxide waste is leaving the body. As the body is replenished with oxygen, all the cells of important tissues are able to efficiently carry out cellular respiration to generate energy using the ample oxygen supply that is attributed with deep diaphragmatic breathing.   More benefits of deep diaphragmatic breathing include:

1. Detoxification and release of toxins
2. Relief of tension and stress
3. Relaxation of the mind/body and provides clarity
4. Relief of emotional problems
5. Pain relief, organ stimulation and contributes to muscle mass
6. Improves the quality of blood, as well as overall body posture
7. Strengthens the lungs, immune system, and nervous system

Breathing allows us to eliminate toxic carbon dioxide from our bodies while supplying our heart and lungs with oxygen that is necessary for cellular respiration and the generation of energy necessary for an organism to function. Cellular respiration is the process of using glucose (from food) and oxygen (from breathing) into a high-energy molecule known as adenosine triphosphate (ATP) which is usable by cells. We breathe so that oxygen is able to penetrate the depths of our lungs and enter the bloodstream so that it is available for the cells to use to generate energy. Without oxygen, these cells lack the ATP they need to survive and experience apoptosis, also known as programmed cell death. If cells continue to die, tissues begin to deteriorate, organ systems fail, and the human body ultimately experiences death. Efficient breathing is critical to our survival.

See the video below to see how when you breathe, we transport oxygen to the body’s cells to keep them working, while also clearing our system of the carbon dioxide that this work generates: how do we accomplish this crucial and complex task without even thinking about it ... 

Breathing is a fundamental process of the body. Naturally, it is an involuntary function that is controlled by the autonomic nervous system. However, respiration itself is an active process since it requires the contraction of thoracic (chest) muscles such as the external intercostal muscles and the diaphragm (lower band-like muscle of the respiratory system). As multicellular organisms we have conscious control over our skeletal muscles, and thus we are able to exercise control of our own breathing regardless of the body’s involuntary capability to breathe on its own. The process of inhalation (taking in air) entails the contraction of the external intercostal muscles which increases the front-to-back width of the thoracic cavity (ribcage) and thereby induces a pressure drop in the lungs, allowing air and oxygen to flow in. Exhalation occurs as the external intercostal muscles and the diaphragm relax so that the thoracic cavity returns to its pre-inspiratory state. This way, the lungs experience a rise in pressure and in turn, carbon dioxide and air are forced outward.

Breathing is an autonomous function. We progress from breathing deeply as infants to more shallowly as we age and we attribute this to stress because stress hormones such as epinephrine and cortisol are known for increasing the rate of respiration. An infant breathes noticeably deeply in comparison to its mother and that is attributed to their differences in stress exposure. An extreme example of the body’s reaction to stress is how the autonomic sympathetic nervous system is likely to evaluate cliff diving as a high stress situation and increase heart rate and respiration accordingly. So as general stress, such as educational or career-related pressure, creates heavier burden on an individual, it would make sense for their breathing to be shallower. Infants do not experience the same stress and are able to continue breathing deeply. Shallow breathing poses the risk of inadequate carbon dioxide release from the body. If high concentrations of carbon dioxide remain in circulation, blood may become more acidic or the carbon dioxide may block oxygen from binding to hemoglobin and impair the gas exchange process to ultimately cause asphyxiation.

Any system where there is a constant exchange of matter and energy from the surrounding environment is called an open system. This makes the human body itself an open system because there is a continuous input of essentials such as oxygen and water as well as output of carbon dioxide and waste. Essential inputs and outputs also include the body’s specific responses (via afferent neurons) to stimuli (as perceived by sensory neurons).

The nervous system is an important key in this process. It is driven by the brain to sense the state of the body and act upon it in order to maintain homeostasis. The response may be controlled by the conscious mind, such as visually observing one’s hair out of place and making the effort to fix it. Or it may be an action of the subconscious mind, like an increase in heart rate when facing a stressful situation. Regardless of the change, the nervous system is always working to maintain equilibrium in the body. Without it, our internal systems would be launched into complete mayhem after just one stressful event and this could ultimately cause irreversible damage.

Here we learn about why we breathe and how we breathe.

Breathing is a fundamental process of the body. It allows us to eliminate toxic carbon dioxide from our bodies while supplying our heart and lungs with oxygen that is necessary for cellular respiration and the generation of energy necessary for an organism to function.

Ordinarily, it is an involuntary function that is controlled by the autonomic nervous system. However, respiration itself is an active process since it requires the contraction of thoracic muscles such as the external intercostal muscles and the diaphragm. As multicellular organisms we have conscious control over our skeletal muscles, and thus we are able to exercise control of our own breathing regardless of the body’s involuntary capability to breathe on its own.

The process of inhalation entails the contraction of the external intercostal muscles which increases the front-to-back width of the thoracic cavity and thereby induces a pressure drop in the lungs, allowing air and oxygen to flow in. Exhalation occurs as the external intercostal muscles and the diaphragm relax so that the thoracic cavity returns to its pre nspiratory state. This way, the lungs experience a rise in pressure and in turn, carbon dioxide and air are forced outward.

Figure showing the excercise homeostatic control in a biological system such as our body. (Courtesy: http://biology4alevel.blogspot.ca/2015/09/108-homeostasis-in-mammals.html)

Homeostasis is a central organizing principle of physiology and refers to the maintenance of a relatively stable internal environment. Put simply, it is the mechanism by which organisms maintain themselves as they are affected by the internal and external environment. It is an automatic control mechanism achieved through the effects of different organ systems working together to return the organism to its equilibrium state.

However, equilibrium is capable of changing with time. For example, an individual may move from living by the sea where there is ample oxygen supply to living up in the mountains where the availability of oxygen is more limited. Since the set-point of oxygen availability is different, the individual experiences acclimatization – an environmentally induced change in physiological function with no genetic change. Circadian rhythms are daily biological rhythms such as sleep-wake cycles and hormonal cycles that can change with physical factors such as relocation or internal factors such as stress. Even so, the body is capable of adapting to these changes, and thus raising the notion of homeodynamics. This word better describes the need for constancy as the organism changes, both in response to its own internal growth and also any environmental influences.

Breathing is the body’s way of maintaining equilibrium between oxygen and carbon dioxide. An inhalation triggers the sympathetic nervous system to release small amounts of cortisol because of the respiratory stress of the carbon dioxide reserve. The parasympathetic nervous system then initiates exhalation so that carbon dioxide is released and blood can be oxygenated. The rate of respiration is ever-changing, affected by consciousness, stress, and mood among others.

The ability of the autonomic nervous system to regulate breathing in the midst of change is homeodynamic. Learning deep breathing techniques allows an individual to practice exercising control over homeodynamic respiration, which ultimately upregulates the control of body function and allows us to survive change.

Related Video:

MIT RES.TLL-004 Concept Vignettes
View the complete course: http://ocw.mit.edu/RES-TLL-004F13
Instructor: Leah Okumura

This video discusses negative and positive feedback loops, how they tie into the body's mechanism of internal regulation, and what happens when these mechanisms fail.

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With over 7 individual organ systems functioning to perform different duties in the human body, one system is necessary to oversee that overall functioning is projected in a positive direction. This is a responsibility of the nervous system.

Figure showing organization of the nervous system (Courtesy: Human Physiology: From Cells to Systems, 3rd Edition by Lauralee Sherwood)

Composed of the brain, spinal cord, nerves, and sensory organs – the nervous system works as a control center for multicellular organisms by allowing communication to occur between the organism and its environment, or simply among its body parts. There are two divisions of the nervous system:

1. The central nervous system (CNS) which is composed of the brain and spinal cord, and
2. The peripheral nervous system (PNS) which is mainly made up of nerves and sensory receptors.

The CNS works subconsciously and even unconsciously to maintain a stable internal environment, called homeostasis, by regulating the fluctuation of internal and external conditions of an organism. Consciously, the CNS is capable of higher functions such as learning and expressing emotion.

The PNS has two branches:

1. A defined voluntary branch called the somatic nervous system (SNS) that is only responsible for conscious body movement, and
2. An involuntary branch referred to as the autonomic nervous system (ANS) that subconsciously controls the functioning of inner tissue.

The ANS is further divided into the sympathetic and parasympathetic nervous systems, whose functions in fact, oppose each other. The sympathetic nervous system prepares the body for a “fight-or-flight” response by releasing adrenaline to increase respiration and heart rate when an organism faces a stressful situation. However, the parasympathetic nervous system acts to lower respiration and heart rate after a stressful situation in a “rest-and-digest” response to ultimately allow the organism to return to its normal, relaxed state.

The human mind is like an iceberg with three distinct realms: the conscious, subconscious and the unconscious. The three realms have different contents and different roles. The structure of the mind gives rise to an important question:

Which of the three realms of the mind is critical for our mental health?

A rapid answer from the top of our heads to this question is of course the conscious. Isn't our  mental health dependent on the state of our conscious mind?

Yes, it is but upon what does the state of our conscious mind depend? The state of our conscious mind depends upon the state of our subconscious mind.

How is the state of the subconscious determined?

The state of the subconscious mind is affected by our conscious mind on one side and the unconscious on the other. On the former side, it is determined by the storehouse of experiential memories accumulated since our birth and by the genetic and biochemical inheritance before we are born on the latter.