Number and lifespan of human cells

In the Name of Allah, The Most Gracious, Most Merciful
A brief about human cells: The number of cells in the human body is more than 1000,000,000,000 (100,000 billion, or 100 trillion) cells. A cell is invisible to the unaided human eye, unless it is magnified 140 times. It weighs 1\1000,000,000 gr., i.e. if 1000,000,000 cells were put on a scale, they would weigh only one gram. Moreover, our human body consumes 125,000,000 cells per second.

The remarkable thing about cells, however, is that a cell has a nucleus that contains chromosomes, which in turn contain hereditary genes. Eight hundred kinds of genes have been recently discovered .

Inside the cell there is a nucleus, a core, and primordial matter - which constitutes the cell’s body - and a membrane - which will be talked about later on. The primordial matter has been very much of mystery and amazement to biologists, who exclaimed:
“A cell is not a structural but rather a functional unit; and it is not the smallest part of the body.”

What is there in a cell?
Most miraculously, inside the cell proteins are made; and inside the cell there are stores for some substances. There are also cleaning apparatus, linking pipes, and energy generators. All such things exist in the cell’s primordial matter. Once again, scientists reiterate that a cell is not a structural but rather a functional unit.

The miraculous thing is that cells vary in respect to life-p. Skin-cells, for example, do not live longer than only 3 hours. Every time you have a bath, you notice that some of your skin is removed. Such are dead cells of your skin. As for absorption cells in the small intestine, they do not live more than 48 hours. In other words, you have to know for sure that every 48 hours, your small intestine is completely renewed. Some other cells, like those of taste, live for 7 days; and the red corpuscles live for 125 days.

You also have to know that every five years, all the cells of your body are completely renewed, except those of two parts: the brain and the heart. This is because if the brain-cells were constantly renewed, man would forget all the information he has acquired. He would study medicine, or engineering, for example, and then soon forget it. He would forget all his knowledge, experience, and memories. That is why Allah’s Infinite Divine Wisdom necessitates that cells of the brain, and also those of the heart, remain the same from the embryonic stage until death.

A Quranic aya and its interpretation:
What is an old person? It is someone in whom factors of death have overcome those of life. This is because cells have certain life-ps; and they are there, both alive and dead, getting little by little into a person’s body. This is clearly manifested by Allah’s Words,
“You (Allah) make the night enter into the day, and You make the day enter into the night, and You bring the living out of the dead, and You bring the dead out of the living, and You give wealth and sustenance, to whom You will, without limit.”
[III; 27]
The above Quranic words “You bring the dead out of the living, and You bring the living out of the dead” show clearly that dying cells give birth to living ones.
Praise be to Allah, the Lord of Creations