Breathing depends on muscular coordination.
Breathing is controlled by the autonomous nervous system through a reflex in the brainstem. Lower levels of oxygen in the blood stimulate the brain centre for breathing to cause the diaphragm to contract. This contraction creates a negative pressure in the chest and air is drawn into the lungs. Afterwards the diaphragm relaxes. The elasticity of the chest and the abdomen, as well as the positive pressure in the abdomen created by the inhaled air, spontaneously force the air out again.
If the muscles are not well relaxed when breathing out, the muscle fibres tend to remain tense. The back, abdomen, pelvis and hips are likely to be affected by not relaxing fully.
It is preferable to exhale through the nose. When agitated, we need more ventilation and frequently open our mouths to allow in more oxygen. We draw air into the lungs to supply oxygen to all the tissues of the body. Our cells need oxygen to maintain their normal metabolism. We breathe out to get rid of carbon dioxide produced by the expenditure of energy in the cells.
Carbon dioxide is transported in the blood stream from the cells to the lungs, and removed from the body when we breathe out.
Breathing - spontaneous or controlled?
We need not think about breathing in and out. Our breathing can take care of itself. But because the muscle fibres in the diaphragm are similar to our skeletal muscles, we can control our breathing. We are able to decide how we want to breathe in, hold our breath, breathe out, etc. In this way, the diaphragm is a rather unique part of the body - its movements may be governed by both unconscious and conscious mechanisms.
The diaphragm takes the form of two domes, and it divides our body into two: the chest, containing the lungs and heart, above it; the abdomen, containing the guts and other inner organs, below it. The muscular fibres of the diaphragm are attached to the lower ribs, and there is a flat tendon sheet on the top of the domes.
In the diaphragm there are rapid and slow muscle fibres which provide a wide range of options for how this muscle may work. The diaphragm has great endurance; it does not get tired as it is well supplied with blood. The main nerve that governs its action comes from a part of the brain that is closely connected to autonomic activities and our emotional life. Accordingly, it is sensitive not only to physical demands but to more subtle factors such as emotional and cognitive stress.
Photo: Roland Nilsson
Yoga and breathing may open our senses and make us more responsive to the beauty of nature. They may also increase our empathy towards others.
Psychological tensions may limit the work and the relaxation of the diaphragm. This will hamper good breathing. If the muscles are not well relaxed when breathing out, the muscle fibres tend to remain tense. The back, stomach, pelvis and hips will also be affected and will not relax fully. Over time, this may lead to bodily pain and other problems.
If the diaphragm is not contracting fully, it may have to use the auxiliary muscles in order to get enough air into the body. The auxiliary muscles are located in the chest, shoulders and neck. Normally, they are used only when we are involved in physical exertions and the body needs extra oxygen. Ideally, these auxiliary muscles should not be used in less strenuous conditions because their use stresses the body. Tensions in the diaphragm, however, may limit the free breathing of the abdomen and lower chest. Such limitations are then compensated for by extra use of the chest and neck muscles. Thus, psychological strain may render the breathing bound and tense, causing more physical stress than is necessary.
Good breathing
Good breathing makes it easier to work through difficult experiences and stress; it also facilitates the use of physical, cognitive and emotional resources. Breathing is “contagious” to those around us. A person whose abdomen moves to the rhythm of relaxed breathing and whose chest seems alive often communicates a calm that spreads to others. Likewise, a mother holding her child will often transmit her state of mind to the infant - whether relaxed or stressed - partly through her breathing, but also by the way she moves. Similarly, a teacher who is at ease may help students to focus, listen and absorb what he is saying, whereas if he is tense, he may distract them by being restless, irritable or critical.
The joy of breathing is something we can feel throughout the day: at work, when spending time with friends or loved ones, or when out walking in the countryside, in the mountains or along the shores of a river, lake or the ocean. It feels good to draw a deep breath of fresh air. The chest and the abdomen move naturally, the air flows freely in and out and vitalizes body and mind. We are in tune with nature.
Photo: Roland Nilsson
Photo: Karin Malmberg