Did you know?

1. Did you know? Some random Anatomy and Physiology trivia!

2. Ooh, that smell! • Body odor comes from a second kind of sweat—a fatty secretion produced by the apocrine sweat glands, found mostly around the armpits, genitals, and anus. • (Yum! The odor is caused by bacteria on the skin eating and digesting those fatty compounds.)

3. Got that Head and Shoulders? • Human dander can cause allergic rashes in dogs and cats—and in other humans.

4. Beauty is only skin deep… • An average adult's skin spans 21 square feet, weighs nine pounds, and contains more than 11 miles of blood vessels.

5. Never say “die”! • There are at least 200 euphemisms for death, including "to be in Abraham's bosom," "just add maggots," and "sleep with the Tribbles" (a Star Trek favorite).

6. Half of all human DNA originally came from viruses, which infected and embedded themselves in our ancestors’ egg and sperm cells.

7. The trigger of death, in all cases, is lack of oxygen. • Its decline may prompt muscle spasms, or the "agonal phase," from the Greek word agon, or contest

8. Chew on this… • Your stomach’s primary digestive juice, hydrochloric acid, can dissolve metal, but plastic toys that go down the hatch will come out the other end as good as new. (A choking hazard is still a choking hazard, though.) • Same with crayons, hair, and chewing gum—all of which will pass through within a few days, no matter what you’ve heard.

9. Within 3 days of death, the enzymes that once digested your dinner begin to eat you. • Ruptured cells become food for living bacteria in the gut, which release enough noxious gas to bloat the body and force the eyes to bulge outward

10. So much for recycling! • Burials in America deposit 827,060 gallons of embalming fluid—formaldehyde, methanol, and ethanol—into the soil each year. Cremation pumps dioxins, hydrochloric acid, sulfur dioxide, and carbon dioxide into the air.

11. For organs to form during embryonic development, some cells must commit suicide. Without such programmed cell death, we would all be born with webbed feet, like ducks

12. Without a trace • Some people never develop fingerprints at all. Two rare genetic defects, known as Naegeli syndrome and dermatopathiapigmentosareticularis, can leave carriers without any identifying ridges on their skin

13. Waiting to exhale • In 1907 a Massachusetts doctor conducted an experiment with a specially designed deathbed and reported that the human body lost 21 grams upon dying. This has been widely held as fact ever since. It's not

14. You are what you eat? • The gastrointestinal tract is a 30-foot tube running from your mouth to your anus. Topologically, your gut has the same shape as those doughnuts you regularly pass through it.

15. Know when to fold ‘em • The small intestine contains so many folds—down to the microscopic level—that its total surface area is about 2,700 square feet, enough to cover a tennis court.

16. Fetuses don't develop fingerprints until three months' gestation

17. A shot in the dark… • Much of our basic understanding of gastric physiology comes from the work of army surgeon William Beaumont, who in 1825 observed the digestive process by inserting food into an unhealed gunshot wound in a French-Canadian trapper’s stomach

18. Maybe it’s just the company. • Tryptophan, an amino acid found in turkey, is often blamed for post-meal drowsiness, but the proteins in the meat largely neutralize it.

19. Feel the burn! • The calories you burn simply digesting food account for 5 to 15 percent of your energy expenditure. Protein and alcohol require the most energy.

20. Eat dirt… • Pica, an eating disorder in which sufferers develop an appetite for nonnutritive substances such as paint and dirt, affects up to 30 percent of young children. Its cause is unknown but possibly linked to subtle mineral deficiencies.

21. Viruses are not alive • They do not have cells, they cannot turn food into energy, and without a host they are just inert packets of chemicals.

22. Do androids dream of electric sheep? • Dreaming is connected to bursts of electrical activity that blow through the brain stem every 90 minutes during REM sleep. Over a lifetime, an average person spends more than six years dreaming, clocking more than 136,000 in all.

23. Survey says… • Depending on gender and how active they are, adults should eat 2,000 to 3,000 calories per day. U.S. agriculture now produces 3,900 calories of food per inhabitant per day.

24. Hold the ice, please… • A seventh grader in Florida recently won her school science fair by proving there are more bacteria in ice machines at fast-food restaurants than in toilet bowl water.

25. The total number of fat cells in your body remains constant once you reach adulthood. Even after radical weight-loss procedures such as stomach stapling, fat cells return to their presurgery numbers within two years. • (Liposuction is the only way to actually reduce the number of fat cells in your spare tire. Diet and exercise just shrink them.)

26. A bitter pill to swallow… • Our sensitivity to bitterness may have evolved to protect us from poisons. Most toxic plant compounds, such as strychnine and cyanide, taste bitter.

27. Brain food? • The brain is about 70 percent fat.

28. Fingerprints don’t actually help you “Get a grip”… they actually reduce friction!

29. No American has died of old age since 1951 • That was the year the government eliminated that classification on death certificates.

30. Don’t sweat it! • The skin releases as much as three gallons of sweat a day in hot weather. The areas that don't sweat are the nail bed, the margins of the lips, the tip of the penis, and the eardrums.

31. A walk in the grass could turn you vegan. • Scientists have shown that tick bites can cause the immune system to produce antibodies to alpha-gal, a carbohydrate in beef, pork, and lamb. These antibodies can induce allergic reactions to meat.

32. B’aaa, humbug! • A 2002 study by Oxford University researchers concluded, brilliantly, that the traditional practice of counting sheep is an ineffective cure for insomnia. The mental activity is so boring that other problems and concerns inevitably surface.

33. I’ll sleep when I’m dead! • A six-year study of a million adults showed that people who get only six to seven hours of sleep a night have a lower death rate than those who get eight hours. 

34. Chew on this… • Your teeth cannot always stand up to your mouth’s native population of bacteria, which produce acids that leach calcium and phosphate from the enamel—the process that leads to cavities.

35. Blowin' in the wind • Globally, dead skin accounts for about a billion tons of dust in the atmosphere. Your skin sheds 50,000 cells every minute.

36. The human body is home to some 1,000 species of bacteria. • There are more germs on your body than people in the United States.

37. It’s a mythtake… • Remember the tongue map you learned about in junior high—the one showing taste receptors for sweet flavors on the tip of the tongue, bitter in the back, and sour on the sides? It’s totally wrong.