Understanding your amazing human body

Human body.

From a completely objective viewpoint, the human body is the most marvelous structure we know of.

It is a masterpiece of engineering.

The daily pounding to which bones and muscles are subjected is so great that it would cause some machines to wear out after only a few years.

These are descriptions given by persons who have made a careful study of the human body.

Engineers see to it that bridges, tunnels, buildings and the like will be able to withstand far more than the usual stresses to which they will be subjected.

The strength that is beyond what would ordinarily be sufficient provides a margin of safety.

To be described as an “engineering marvel,” the human body should, therefore, have extraordinary safety factors.

Does it?

The body safety features

Most of the blood chemicals are in a delicate balance.

But there is still a rather wide built-in margin of safety.

For example, the blood-sugar level is considered “normal” if present in amounts of 80 to 120 milligrams per 100 cubic centimeters of blood. 

However, the blood-sugar level can drop considerably without giving rise to serious problems.

Not until it plunges to about half normal,or below about 50 milligrams per 100 cubic centimeters, will the person experience ill effects.

The heart is capable of doubling its rate of contraction, pumping out about double the volume of blood.

At the same time, the arterial blood pressure may increase by 30 or 40 percent.

Yet, unless previously damaged, the heart is able to take on this extra load without any difficulty.

The volume of oxygen transported in the bloodstream from the lungs is three and a half times as great as is generally used by the tissues. 

Because of this, one lung may cease functioning, or be completely removed surgically, and yet life can continue with reasonably normal respiratory efficiency.

Astounding, too, is the body’s ability to endure surgical removal of vital organs. For example, one kidney may be removed without severely endangering a person’s life.

With only about half a kidney remaining, a person may continue to live without being plagued by serious kidney troubles.

Within less than two days, the person losing both of his adrenal glands would die.

Yet, with only a tenth of the adrenal tissue remaining, he can continue living.

Doctors have cut away large sections of the brain without endangering the patient’s life or seriously affecting mental and physical functions. 

The brain is also well protected from injury by the hard skull.

Other organs can likewise continue their essential functions when large sections are removed surgically.

A person may get along with one fifth of his pancreas or one fourth of his liver.

Most of his stomach may be removed without dangerously affecting digestion and nutrition.

Total removal of the stomach is crippling, but not fatal.

About half of the small intestines and most of the large intestines may be cut away and still the person continues to live.

The body has a marvelous defense system against disease.

Although alive with bacteria, the skin provides a protective shield for the whole body against their encroachment. 

If harmful bacteria enter the body through a cut or scratch, the body’s defense system goes to work.

White blood cells rush to the area and start destroying the invading organisms.

The lymph nodes serve as yet another part of the defense system.

Whenever disease organisms enter the body, the lymph nodes manufacture antibodies to combat the invaders.

Antibodies vary according to the kind of organism infecting the body.

Some antibodies fight disease organisms directly.

Others render harmless the poisons released by the bacteria.

Still others cause the bacteria to stick together so that white blood cells can destroy them more readily.

Being elastic, the skin also permits the effects of a fall or a blow to be spread over a large area and thus reduces the extent of the injury.

Truly your body is well designed, with an ample margin of safety.

The body waterproof insulation and heat control

Besides protecting the body from the invasion of disease organisms and minimizing the effect of blows or falls, the skin serves to provide a waterproof covering for the body.

Were it not for this feature, a walk in the rain or a bath would be hazardous.

Our bodies would swell and our blood would be diluted.

Swimming in seawater would result in shrinkage, since, from a chemical standpoint, salt water is more concentrated than blood.

The release of water through the skin in the form of perspiration and by diffusion, on the other hand, is essential in maintaining the body’s heat balance.

Even hair growing in the skin has its place in heat control.

The hair of the head shields the brain from getting overheated when subjected to the hot sun.

On the palms of the hands, the fingers and the soles of the feet, the thick skin functions as a good heat insulator.

Dry skin also serves as a fine electrical insulator.

This is indeed a blessing at a time when electrical appliances have come into common use.

Surely, something as attractive and versatile as human skin can rightly be labeled an “engineering marvel.”

The body framework

The bones provide the structural framework, keeping the organs in place and preserving the shape of the body. In themselves, the bones are an engineering marvel.

Having a total weight of some twenty pounds, a human’s bones. provide an ideal combination of lightness and strength.

No human engineer can design a framework that can accommodate continual growth for some twenty years without having to shut down the structure that this framework supports.

Bones, however, grow along with the rest of the body without as much as one stoppage in a person’s activities.

Another feature of body engineering that man cannot duplicate is self-repair.

A broken bone, when properly treated, will heal and can thereafter function just as well as it did before the break occurred.

Furthermore, bones fit together freely, connected by self-lubricating joints.

Interestingly, so-called self-lubricating systems in automobiles are but a recent engineering development.

The body versatility

The capacity of the human body simply staggers the imagination.

Think of human’s accomplishments in the fields of architecture, building, music, sports, carving, sculpture, painting and technology.

The hands that firmly grasp an ax to chop down a tree can guide a knife in carving an object of beauty or move the scalpel to make minute surgical incisions.

The legs and feet that are used for walking serve just as well for running, jumping and climbing.

What single machine could come close to duplicating even a few of the many movements and activities of the human body?

Amazing, too, is the fact that the fuel for all the many functions of the body can be derived from, not just one, but many sources.

And the greatly varied fruits, vegetables and meat that may be eaten to supply the body’s needs add to the enjoyment of life.

Yes, when we consider just a few things about the marvelous human body, we cannot help but be impressed.