The brain is responsible for coordinating all involuntary bodily mechanisms, which, in themselves, occupy a far greater amount of the body’s functions than conscious activities. This involuntary activity includes facilitating digestion of food, the movement of muscles, and the reception of sensory signals, and responses such as pain, hunger, or the adrenaline rush.
At present, my brain is facilitating my capacity to see, though the specific items I concentrate are determined by my personal choice. I may choose to touch the keyboard, but the sensation this creates on the tips of my fingers is engineered by the brain without my consent. My heart beats involuntarily; I would not be able to engage in many other activities if I were forced to consciously guide it through its every motion.
The majority of human cells regenerate both to repair damage to a given tissue and to ensure a lifespan beyond that of the given cells. Since human beings will inevitably suffer from a wide variety of minor harms and accidents throughout their lives, it is useful for the body to possess the ability to partially repair itself.
The walls of the stomach, after being eroded by stomach acid, can grow back to their former thickness. A cut can heal by the generation of new skin cells. In the event that white blood cells suffer heavy casualties when resisting microbes, new ones can take their place. These cells are generally short-lived and last for a few years at the most. They must be replaced in order for the human organism to continue existing for decades.
If heart and nerve cells possessed the ability to regenerate, two of the leading causes of “natural” death, brain atrophy and heart failure, would be eliminated, as new vitality would be imparted upon these organs by successive creation of new cells to take the place of old and declining ones.
There are no apparent negative drawbacks to the regeneration of heart cells, but the regeneration of nerve cells may hold the potential of memory loss. If a particular neuron in the brain were responsible for storing a particular datum of information, that datum might be lost once that cell atrophied, though the organism could continue functioning and acquiring new information by the use of the fresh neuron that would arise in the old one’s place.
Of course, in a technological society, where forgotten information can quickly be recalled by the reading of books or the viewing of audiovisual records of multiple varieties, this drawback would not be substantial to bring about complete amnesia or loss of personality within the individual.