Published on February 1st, 2013 | by No Artificial
7 Extraordinary Facts About
The Human Body
Many of the most fascinating findings in all areas of science are being played out in our bodies.
The latest research suggests the appendix might be used to store beneficial bacteria.
But appendix is getting a bad press. It is usually treated as a body part that lost its purpose millions of years ago. All it appears to do is often get inflamed and cause appendicitis.
In fact, it serves a very useful function – by acting as a safe house for beneficial bacteria in our bodies, explains Bill Parker, an assistant professor of experimental surgery at Duke University Medical Center, in Durham, North Carolina.
“My idea is that the appendix is a storehouse, a cultivation center for the normal, beneficial bacteria that our gut needs,” he says. “That safe house would be necessary and useful in the event that the main compartment of bacteria, the large bowel, got contaminated with some kind of infectious organism and got flushed out.”
2. HAIR LOSS
Humans have about the same number of hair follicles as a chimpanzee has, it’s just that our hairs are useless, so fine they are almost invisible. It’s still a mystery why we lost our protective fur. It has been suggested that it may have been to enable early humans sweat more easily, or to make life harder for parasites, or even simply because our ancestors were partially aquatic.
Although the idea of early humans co-operating more when they were moving out of the trees into the savanna is making more sense. When animals are bred for co-operation, as we once did with wolves to produce dogs, they become similar to their infants. In a 40-year research starting in the 1950s, Russian foxes were bred for docility.
Over the period, adult foxes become more and more like large cubs, spending more time playing, and developing sagging ears or floppy tails. Humans also have some features of infantile apes – large heads, small mouths and, significantly here, finer body hair.
3. RED CELLS
Red blood cells, or erythrocytes, are the most typical type of blood cell. When you see blood oozing from a cut, you might believe that it is red because of the iron in it, rather as rust has a reddish colored hue. But the presence of the iron is a coincidence. The red color arises because the iron is bound in a ring of atoms in hemoglobin called porphyrin and it’s the shape of this structure that produces the color. Just how red your hemoglobin is depends on whether there is oxygen bound to it. When there is oxygen present, it changes the shape of the porphyrin, giving the red blood cells a more vivid tone.
There is more bacterial life inside you than human. There are around 10tn of your own cells, but 10 times more bacteria. Although the vast majority of bacteria are harmless. Some are beneficial.
In the 1920s, an American engineer examined whether animals could live without bacteria, hoping that a bacteria-free world would be a much healthier. James “Art” Reyniers made it his life’s work to produce environments where animals could be raised bacteria-free. The final result was obvious. It was possible. But many of Reyniers’s animals died and those that survived had to be fed on special food. This is because bacteria in the intestine play a crucial role in digestion. They provide enzymes necessary for the uptake of many nutrients, synthesize certain vitamins and boost absorption of energy from food.
5. EYELASH MITES
Depending on how old you are, it’s quite likely that you have eyelash mites. These small creatures live on old skin cells and the natural oil (sebum) produced by human hair follicles. They are generally harmless, though they can cause an allergic reaction in a minority of people. Eyelash mites grow to a third of a millimeter and are near-transparent, so you are less likely to see them with your eye. Put an eyelash hair under the microscope, though, and you may see them. Around half the human population have them, a proportion that rises as we get older.
There is some difference in the number of senses that scientist say that humans have, but there’s complete agreement that it’s more than 5.
Here is the simple example. Put your hand few inches away from a hot iron. None of your five senses can tell you the iron will burn you. However you can feel that the iron is very hot from a distance and won’t touch it. This is thanks to an additional sense – the heat sensors in your skin. In the same way we can recognize pain or tell if we are upside down.
7. OPTICAL DELUSION
The image of the world we “see” is artificial. Our brains don’t produce a picture the way a camcorder works. Our brain constructs a model of the world from the data provided by modules that measure light and shade, edges, curvature and so on. This makes it simple for the human brain to paint out the blind spot, the area of your retina where the optic nerve joins, which has no sensors. It also reimburses for the rapid jerky movements of our eyes known as saccades, giving a false picture of steady vision.
TV, films and optical illusions work by misleading the brain about what the eye is seeing. This is also why the moon seems to be much bigger than it is and seems to vary in size: the true optical size of the moon is similar to a hole created by a hole punch held at arm’s length.