Author: Mufti Noor Mohammad Mohibi
The Quran: A Miracle Beyond Time- A Study of Its Miraculous Nature (part 56)
The Human Respiratory System: A Sign of Divine Greatness and Wisdom
Among the greatest signs of God’s power and design that constantly accompany us—but which we often overlook because of their very closeness—is the phenomenon of breathing. Every night we sleep peacefully while our lungs continue to function tirelessly, our heart beats regularly, our digestive system operates flawlessly, and our body’s purification mechanisms perform their duties with astonishing precision.
If the control of these vital systems were left to our own will, could anyone sleep for a moment or even sit calmly in conversation with another?
In this simple yet profound reality lies a sign of God’s infinite knowledge and power: وَفِي أَنفُسِكُمْ أَفَلَا تُبْصِرُونَ Translation: “And in yourselves—will you not then, see?” (Al-Dhariyat: 21)
Voluntary and Involuntary Actions in the Human Body
The Wonder of Involuntary Actions
Most of the body’s vital functions occur involuntarily—that is, without our awareness or conscious decision. Among them are:
-
Heartbeat
-
Rhythmic lung movements
-
Digestion and absorption of nutrients
-
Secretions of endocrine glands
-
Regulation of body temperature
-
Control of fluid balance and heart rate
These involuntary processes are controlled by a cluster of nerve centers in the medulla oblongata, the lower part of the brainstem. This vital area, known as the “center of life”, houses the main control centers of the body, including:
-
The respiratory control center
-
The cardiac control center
-
Centers for contraction and dilation of blood vessels
-
Centers for swallowing and chewing
-
Centers for voice and speech
-
Centers regulating sweating, salivation, sleep, and wakefulness
-
Centers balancing blood sugar and body temperature
-
Centers controlling reproductive hormones and the menstrual cycle
Damage to this vital region usually results in instant death, since all essential life processes are regulated here.
The Respiratory Center and Its Remarkable Mechanism: “Inhalation and Exhalation”
In the lower part of the brainstem lie two main centers:
-
The inspiratory (inhalation) center
-
The expiratory (exhalation) center
These two centers operate alternately and in perfect harmony. Stimulation of one inhibits the other, maintaining the balance necessary for steady breathing. If both were stimulated simultaneously, the respiratory system would collapse.
The Role of Carbon Dioxide (CO₂)
Breathing is primarily regulated by the amount of carbon dioxide (CO₂) in the blood. When CO₂ levels rise, the inspiratory center is stimulated, making breathing faster and deeper to expel the excess gas. When CO₂ levels drop, breathing slows or stops altogether.
For example:
-
If the concentration of CO₂ rises by only 0.2% above normal, breathing rate doubles.
-
If it falls by 0.2%, breathing may stop completely.
This precise balance is a clear sign of divine design. In situations like the use of gas heaters in closed bathrooms, dangerous increases in CO₂ concentration can cause respiratory failure and death.
Voluntary and Involuntary Breathing
Humans can voluntarily take deep breaths or hold their breath, thanks to neural pathways connecting the cerebral cortex to the respiratory centers. However, even during unconsciousness or deep sleep, breathing continues automatically, since the brainstem centers respond directly to chemical stimuli such as CO₂ levels.
This perfect coordination between voluntary control and automatic regulation is a striking example of God’s infinite wisdom in the creation of humankind.
The Lungs: A Masterpiece of Divine Engineering
Internal Structure of the Lungs
The lungs are two spongy organs located within the chest cavity, connected to the outside through the trachea (windpipe). The trachea divides about 23 times into smaller branches, eventually reaching the alveoli—the smallest functional units of the lungs.
-
Diameter of the trachea: about 5 cm
-
Diameter of an alveolus: about ¼ micron
-
Number of alveoli: over 350 million
-
Total alveolar surface area: approximately 70 square meters (more than 2000 times the cross-sectional area of the trachea)
This immense surface area allows for highly efficient gas exchange between the blood and inhaled air.
The Role of Cilia
Throughout the respiratory tract—from the trachea to the alveoli—the walls are lined with ciliated cells. Each cilium is about 6 microns long and 0.2 microns wide, beating upwards 1,000–1,500 times per minute to remove dust, microbes, and other pollutants from the airways.
If a foreign object such as a drop of water enters the trachea, coughing occurs as a powerful defensive reaction, expelling air at speeds of up to 900 kilometers per hour to clear the airway.
The Inability of Science to Replicate the Lungs
To this day, medical science has failed to achieve a complete lung transplant, primarily because the intricate neural network controlling the cilia and the microscopic structures of the lungs are extraordinarily complex.
This, too, stands as another unmistakable sign of divine precision and wisdom in creation.
Continues…
Previous Part/ Next Part
Reference:
[1]. Dhariyat: 21.
