The human body has 206 bones. Many of them are in the hands, feet and spine, where they provide essential flexibility.
Each hand/wrist has 26 bones. Each ankle/foot has 26 bones. These numbers are crying out to be memorized.
The human body is put together with only 8 main systems:
1) The skeletal system, or bones, for structure.
2) The muscles for movement. There are about 700 muscles.
3) circulatory system, (heart, etc., shown at right) moves blood around.
4) respiratory system, (lungs, etc.) puts oxygen in blood stream.
5) digestive system (mouth, stomach, intestines) puts fuel or food energy into blood stream.
6) Endocrine system–glands to help regulate everything (e.g., pituitary, thyroid).
7) Nervous system, The brain allows control of muscles, thinking, senses, consciousness, etc.
8) Reproductive system, The key thing is the number 8. Students can assemble and disassemble their own bodies. Students can analyze why we need this or that system. It’s all fairly logical once they know the number 8.
The brain weighs about 3 pounds or 1/50 of the body’s weight. But it uses 25% or 1/4 of the energy required by the body.
Most people would assume the brain is resting at night. In fact, it’s busier than ever during sleep. There’s a lot going on in there that we don’t understand. Dreams, for example.
Signals or nerve impulses travel from the brain to the finger tips, for example, at the speed of 450 feet per second.
The brain contains at least 100 billion nerve cells. Or perhaps 200 billion…
But what do these numbers mean??
Before considering the cell, let’s talk about million/billion/trillion:
One of the most bizarre aspects of modern educational theory is that children shouldn’t be asked to memorize anything. Quackery. First thing to memorize: what is meant by a million, billion and trillion. Without these basic words in mind, science is hard to talk about, not to mention economics, the history of the Earth, or populations of, for example, people in India, fish in the sea, and stars in the sky.
A million is one with 6 zeros: 1,000,000 (that is, a thousand thousands).
A billion is one with 9 zeros: 1,000,000,000 (that is, a thousand millions).
A trillion is 12 zeros: 1,000,000,000,000 (that is, a thousand billions).
Every human starts from a single egg cell. This cell divides and divides and divides…Becoming trillions of cells!…Some cells specialize in one direction, some in another direction. By birth there are 200 DIFFERENT KINDS OF CELLS–e.g. lung, heart, skin, muscle, brain, liver, teeth, etc.
At birth the body might consist of about two or three trillion cells. An adult might consist of about fifty trillion cells. Each of these things is VERY small…microscopic….About 250 cells will fit on this red period.<< Red blood cells are among the smallest and simplest--about 2000 of them fit on that red period! All of which is amazing, but the story is just beginning... A typical cell is so very tiny...What could possibly be in there? Most drawings show an outer wall, with a nucleus at the center. That's it. Fact is, each cell is vastly complex, as complex as a huge industrial facility. There are hundreds, even thousands of separate parts. Each little part might contain 10 billion molecules. All of this stuff has to be brought in, used, stored, moved around. Which brings us to the main thing: the cell is ALIVE. It is autonomous. Cells can split and reproduce all their complexity in a few hours. Millions of cells are being born and dying each minute.Publisher: sulaiman isse