All parts of the human body get tired eventually - except the tongue.
The human body is not designed for swimming in minus 1.7 degree centigrade water.
The human body experiences a powerful gravitational pull in the direction of hope. That is why the patient's hopes are the physician's secret weapon. They are the hidden ingredients in any prescription.
You aren't your work, your accomplishments, your possessions, your home, your family... your anything. You're a creation of your Source, dressed in a physical human body intended to experience and enjoy life on Earth.
The body politic, as well as the human body, begins to die as soon as it is born, and carries itself the causes of its destruction.
For something to collapse, not all systems have to shut down. In most cases, just one system is enough. For example, the human body is a system of systems. If just one system, such as the cardiovascular system, shuts down, death follows.
Like bones to the human body, the axle to the wheel, the wing to the bird, and the air to the wing, so is liberty the essence of life. Whatever is done without it is imperfect.
There is something fundamentally fascinating about the mechanics, I guess, of the human body and where consciousness and mind exist, and what you can do with the mechanics of the body while keeping those intact, and where those two cross over.
If the human body recognized agony and frustration, people would never run marathons, have babies, or play baseball.
Basically, most good science in space flight has to do with the behavior of the human body in space. That is where we are lacking info, and where info can only be obtained by flying in space.
One thing we've learned about space is that the human body starts to fall apart after relatively short exposures to microgravity.
The human body has limitations. The human spirit is boundless.