Author: Mufti Noor Mohammad Mohibi
The Quran: A Miracle Beyond Time- A Study of Its Miraculous Nature (Part 49)
The Greatness of the Circulatory System in the Divine Verses
One of the most remarkable signs of God’s greatness in the universe and within human beings is the complex and extraordinary circulatory system. Allah says in the Holy Qur’an: وَفِی أَنفُسِكُم أَفَلَا تُبصِرُونَ Translation: “And within yourselves; will you not then, see?” (Qur’an 51:21)
This verse invites humans to reflect on the precise and harmonious systems in their bodies, the greatest of which is the circulatory system. Also known as the cardiovascular system, it is responsible for transporting vital fluids and nourishing cells, and it represents one of the miracles of God’s creation in the human body.
Definition and Importance of the Circulatory System
The circulatory system (جهاز الدوران) in humans is responsible for delivering blood rich in nutrients and oxygen to all cells. Every living being requires nutrients to maintain life and perform activities. While the digestive system transfers food from the external environment into the body and breaks it down, it is the circulatory system that delivers these nutrients to individual cells.
In complex organisms like humans, this circulation occurs in a closed and regulated circuit. Blood continuously flows through the vessels, propelled by the heart. Without a powerful pump like the heart and a network of intricate vessels, blood flow and cell nourishment would not be possible.
Structure and Components of the Circulatory System
The circulatory system consists of:
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Heart: A muscular pump that drives blood circulation.
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Vessels: Including
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Arteries: Carry oxygen-rich blood.
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Capillaries: Extremely tiny vessels where exchange with cells occurs.
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Veins: Carry blood back to the heart.
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The network of vessels covers the human body extensively, with a total length exceeding 150 kilometers.
Remarkable Features of the Circulatory System
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Humans have approximately 100–160 billion capillaries, tiny vessels spread throughout the body.
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7–10 liters of blood circulate through these vessels continuously each day.
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Red blood cells travel from the heart to the entire body and return in just 23 seconds.
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Blood circulates roughly 3,700 times per day.
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The heart pumps an average of 8,000 liters of blood per day, equivalent to 8 cubic meters, weighing about 8 tons.
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Over an average human lifespan, the total blood circulated reaches 150,000–250,000 tons, equivalent to filling several large buildings.
The Power of the Circulatory System
The heart’s pumping power can be analogized to the energy needed to lift a train from sea level to a height of 4,800 meters!
Allah says: هَٰذَا خَلقُ ٱللَّهِ فَأَرُونِی مَاذَا خَلَقَ ٱلَّذِینَ مِن دُونِهِۦۚ بَلِ ٱلظَّٰلِمُونَ فِی ضَلَٰل مُّبِین Translation: “These are the creations of Allah. So show Me what those besides Him have created. Rather, the wrongdoers are in clear error.” (Qur’an 31:11)
This verse encourages reflection on the complexity of creation, including the circulatory system.
Arteries and Veins: The Pathways of Blood
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Arteries: Carry oxygen-rich blood from the heart to all body parts. They gradually branch into smaller vessels and capillaries, delivering nutrients and oxygen to cells.
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Veins: Return deoxygenated blood from tissues back to the heart.
The Amazing Function of Venous Valves
A remarkable feature of the circulatory system is the one-way valves in veins, allowing blood to flow toward the heart and preventing backflow.
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These valves are small sac-like structures on the vessel walls.
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They open as blood moves upward and close to stop backflow.
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This system is especially crucial in veins carrying blood from lower extremities, such as the legs, against gravity.
Circulatory Disorders and Valve Dysfunction
If venous valves weaken or malfunction, blood does not return efficiently to the heart, causing it to accumulate in the veins. This results in increased venous pressure, swelling, pain, and darkened skin—commonly known as varicose veins.
Thus, the proper function of these valves is vital and exemplifies the precise design and wisdom of God in creation.
Conclusion
The circulatory system is a complex and astonishing system that sustains life in every cell. Its precise structure and coordinated function reflect God’s immense power and wisdom.
Allah says: لَقَد خَلَقنَا ٱلإِنسَٰنَ فِی أَحسَنِ تَقوِیم Translation: “Indeed, we created man in the best of forms.” (Qur’an 95:4)
This verse emphasizes the perfect and exquisite design of humans, including the circulatory system.[3]
Continues…
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References:
[1] Luqman: 11
[2] Tin: 4
[3] Encyclopedia of Scientific Miracles in the Qur’an and Sunnah, Vol. 1, pp. 144–146
