Last week’s column began a review of “The Wonders Inside THE HUMAN BODY,” a Silver Dolphin Book by Jan Strandling published in 2009. Following are more nuggets of information culled from “THE HUMAN BODY.” One quarter of all of your bones are in your feet, each foot having 26 bones, 33 joints and 19 muscles. The most sensitive parts of your body are your hands, lips, tongue, feet and fingertips. Each fingertip has 100 touch receptors. The most numerous pain receptors are the free nerve endings. There are free nerve endings around each your hair follicles. So it’s not surprising that when you pull on someone’s hair, it can be quite painful.
Your ears help you maintain your balance. Deep inside your ears are semicircular canals with fluid that moves as your body moves. There are tiny hairs there that sense motion; they tell your brain where your head Is placed. These hairs deep inside your ears are your balance receptors.
You have about 10,000 taste buds on your tongue. Inside these buds are taste detecting nerve cells. When food enters your mouth, the saliva dissolves the food. Special chemicals are released, and the taste detecting nerve cells send a message to your brain.
This can provides an early warning system. If something bitter is sensed, you will probably spit the food out as an automatic reaction.
Different parts of your tongue are sensitive to the four main tastes. The tip of your tongue senses sweetness. On the left and right edges of your tongue, just in back of your ‘sweet detectors’ are receptors for saltiness. A bit further back on either side are receptors for sourness. In the back of the tongue (about as far as you can see in a mirror) are cells for detecting bitterness.
Olfactory cells, deep in your sinuses have about 2 million odor detecting hairs called cilia. There are about 20 different cilia to detect different smells. Recent research estimates that your nose could distinguish many millions of smells.
As far as muscles, the biggest muscle in your body is the gluteus maximus in your buttocks. I have noticed that some baseball and softball players have large behinds. These players have well developed gluteus maximus muscles, giving them a lot more power behind their pitches and throws than lighter players.
The process of digestion involves a tortuous path that starts with your mouth, your stomach, through the small intestines, the large intestines and lastly the colon where dried waste is expelled. In the stomach, there are muscular contractions to churn the food as it is soaked with acidic juices.
Without your awareness, the digested material is slowly pushed along the intestines by contractions; in a day or two, you feel the urge to evacuate. A good amount of fiber (matter that can’t be digested, such as oat bran or flaxseed) is helpful to keep the process running smoothly.
Your bones have a hard, outer surface. But deep inside, the tissues are spongy. Here there are pockets filled with blood marrow. The red bone marrow is where red blood cells are made. If your bones were solid all the way through, they would be too heavy and difficult to move. The bones have blood vessels that run into and out, to provide nutrients and oxygen as bones are continually renewing themselves.
One problem with long bouts of weightlessness on the International Space Station is that the crews’ bones become weaker owing to the lack of weight. This would be even more of a problem for a human mission to Mars.
The astronauts would spend two years away from the Earth’s gravity with an ongoing flight (no weight felt) lasting six months, followed by a year on Mars (40 percent of Earth’s gravity), followed by a six month return flight with weightlessness. (The only time weight would be felt would be when the rockets fire, three times travelling to Mars, and three times on the return back.) SKY SIGHTS AHEAD: In early May, the planet Mars appears due south in the late evening. Mars has a yellow or orange tint and shines steadily. The very bright planet Jupiter is in the west and is best viewed early in the evening.
The planet Saturn is nearly opposite the sun, rising in the dusk in the southeast and being visible all through the night. Saturn is the dimmest of the evening planets, matching in brightness the brighter night stars.
The planet Venus is glorious in the eastern dawn, rising about 90 minutes ahead of the sun. Tonight, the moon will appear near the bright planet Jupiter. On May 6, the evening moon will appear half full; the moon will be at its best for spotting the moon’s craters and mountain ranges with binoculars or a telescope.
The Cumberland Astronomy Club will have evening pubic telescope viewing on May 10 at the LaVale Public Library just off the National Road (Route 40). Weather permitting, Jupiter, Mars and the moon will be observed. All interested are invited to attend.
Bob Doyle invites any readers comments and questions. Email him at firstname.lastname@example.org . He is available as a speaker on his column topics.