As the young red blood cell grows and takes on an adult form in the marrow of the bone, it loses its nucleus, and it increases its production of hemoglobin. Hemoglobin is the red pigment, or color of blood, and contains iron, combined with protein. (Oxygen combined with iron is red; the more oxygen iron has bound to it, the redder it is.)
When blood passes through the lungs, oxygen attaches itself to the hemoglobin of the red cells. From there, the red cells carry the oxygen through the arteries and the capillaries to all other cells of the body. The arteries appear reddish because the iron in the blood gives up its oxygen to the cells that need it as the red blood cells travel throughout the body. By the time the blood is back on its way to the heart and then to the lungs it has less than half as much oxygen as it did before. The veins, therefore, do not get as much oxygen as the other tissues and they appear bluish.
1. On average, a man spends about five months of his life shaving.
2. On average, a hair strand’s life span is five and a half years.
3. On average redheads have 90,000 hairs. People with black hair have about 110,000 hairs.
4. Next to bone marrow, hair is the fastest growing tissue in the human body.
5. In a lifetime, an average man will shave 20,000 times.
6. Humans have about the same number of hair follicles as a chimpanzee has.
7. Hair will fall out faster on a person that is on a crash diet.
8. The longest human beard on record is 17.5 feet, held by Hans N. Langseth who was born in Norway in 1846.
9. The average human head weighs about eight pounds.
10. The reason why some people get a cowlick is because the growth of their hair is in a spiral pattern, which causes the hair to either stand straight up, or goes to a certain angle.
11. The reason why hair turns gray as we age is because the pigment cells in the hair follicle start to die, which is responsible for producing “melanin” which gives the hair colour.
12. The fastest growing tissue in the human body is hair.
13. A lifespan of an eyelash is approximately 150 days.
14. A survey done by Clairol 10 years ago came up with 46% of men stating that it was okay to color their hair. Now 66% of men admit to coloring their hair.
15. The big toe is the foot reflexology pressure point for the head.
16. The average human scalp has 100,000 hairs.
17. The first hair dryer was a vacuum cleaner that was used for drying hair.
18. Ancient Egyptians used to think having facial hair was an indication of personal neglect.
19. The loss of eyelashes is referred to as madarosis.
20. Hair and fingernails are made from the same substance, keratin.
21. Eyebrow hair lasts between 3-5 months before it sheds.
22. A Russian man who wore a beard during the time of Peter the Great had to pay a special tax.
23. Everyday approximately 35 meters of hair fiber is produced on the scalp of an adult.
24. Hair is made from the same substance as fingernails.
25. Brylcreem, which was created in 1929, was the first man’s hair product.
The hectare (abbreviated ha) is a unit of area equal to 10,000 square meters and used exclusively for measuring land. To get a sense of how big this is, imagine a football field. A football field is almost exactly 100 meters from one end line to the opposite goal line.
Imagine a square of that length on each side, and you’ve got an area of one hectare. There are 100 hectares in one square kilometer, so one square kilometer is the same area as a square that is ten football fields on one side.
Scientists do not know exactly why people need sleep, but studies show that sleep is necessary for survival. Sleep appears to be necessary for the nervous system to work properly. While too little sleep one night may leave us feeling drowsy and unable to concentrate the next day, a long period of too little sleep leads to poor memory and physical performance.
Hallucinations (seeing things that aren’t really there), vision problems, and mood swings may develop if sleep deprivation continues.
Like many inventions, the development of the modern zipper can be traced to a series of events. In 1893, Whitcomb Judson patented and marketed a “clasp locker,” a complicated hook-and-eye shoe fastener. Together with businessman Colonel Lewis Walker, Whitcomb launched the Universal Fastener Company to manufacture the new device. He did not use the word “zipper,” although many people often credit him as the zipper’s creator. Instead, it was Swedish-born Gideon Sundback, an electrical engineer who was hired to work for the Universal Fastener Company, Who gets the credit.
He was responsible for improving Judson’s fastener, and by December 1913, he had designed the modern zipper. Sundback increased the number of fastening elements from four per inch to ten or eleven, had two facing-rows of teeth that pulled into a single piece by a slider, and increased the opening for the teeth guided by the slider. Sundback also created a machine that was able to manufacture the zipper.
Skin color—which ranges from light pink to dark brown—is determined by the amount and type of the pigment melanin there is in the skin. Melanin comes in two types: phaeomelanin (red to yellow) and eumelanin (dark brown to black).
Both amount and type are determined by four to six genes. One copy of each of those genes is inherited from your father and one from your mother. Each gene comes in several coding sequences, which results in a variety of skin colors around the world.
Dust is made up of particles of all sorts of things. In places where people live, a great deal of dust comes from flakes of dead skin, which are being shed all the time. Dust mites, tiny microscopic creatures that feed on this dead skin, make up dust, too (including their waste and tiny skeletons). Particles of the environment contribute to dust as well: grit from the sidewalk, salt from the sea, dry earth, pollen from plants, pet dander, molds, and smoke from burning materials. And Earth gets 10 tons of dust from outer space every day, from the meteors that burn up as they enter our atmosphere. Sometimes these ingredients cause allergic reactions, such as sneezing and coughing.
The brain is the body’s command center; everything we do—eating, talking, walking, thinking, remembering, sleeping—is controlled and processed by the brain. As the most complex organ in the human body, the brain tells us what’s going on outside our bodies (whether we are cold or hot, for instance, or whether the person we see coming toward us is a friend or a stranger) as well as what’s going on inside our bodies (whether we have an infection or a broken bone, or whether we feel happy or sad).
The key to the body’s nervous system, the brain contains between 10 billion and 100 billion nerve cells, or neurons. Neurons combine to form the body’s nerves, thin cords that spread from head to toe and all parts in between. Neurons take in and send out electrical signals, called impulses, that control or respond to everything your body does and feels. The brain is like a very busy, high-speed post office, constantly receiving messages and sending them out all the time; it handles millions of nerve impulses every second.
Today’s computers contain millions of transistors placed in a tiny piece of sili- 162 con, some so tiny that they can fit in an ant’s mouth. The transistors (devices that control the flow of electric current) are packed and interconnected in layers beneath the surface of the chip, which is used to make electrical connections to other devices. There is a grid of thin metallic wires on the surface of the chip.
This silicon chip was independently co-invented by two American electrical engineers, Jack Kilby and Robert Noyce, in 1958–1959. The chip, along with the invention of the microprocessor, allowed computers to get smaller and more efficient. Silicon chips are also used in calculators, microwave ovens, automobile radios, and video cassette recorders (VCRs).
Camels are the only animals with humps. A camel’s hump is a giant mound of fat, Which can weigh as much as 80 pounds (35 kilograms). The hump allows a camel to survive up to two weeks without food. Because camels typically live in the deserts of Africa and the Middle East, where food can be scarce for long stretches, their hump is key to their survival. When camels are born their humps are empty pockets of flexible skin. As a camel grows and begins to form its fatty tissue reserves, the humps begin to fill out and take shape.
The humps also come in handy for humans who have domesticated the camel. For thousands of years, people have used these strong, resilient creatures for transportation and for hauling goods. The two-hump, or Bactrian, camel was domesticated sometime before 2500 B.C.E., probably in northern Iran, northeastern Afghan – istan, and northern Pakistan. The one-hump, or Dromedary, camel was domesticated sometime between 4000 and 2000 B.C.E. in Arabia.