The Human Body: 45 Surprising Insights – Part 5



The average human body contains about 0.017 grams of radioactive potassium-40 which decays at the rate of 4,400 or so nuclear disintegrations per second. The products of this decay are mostly calcium with about 10% argon.

27. Soleus, the human calf muscle, acts as a second heart, pumping blood upwards from the periphery of the body.

28. The average human body has 60,000 miles of blood vessels.

29. Nerve impulses travel through the human body at speeds of up to 250mph, faster than a Formula 1 racing car. The fastest transmissions use a lot of energy, so are reserved for neurons that need to send urgent information, like to tell your brain you are burning your fingers.

30. The Human body contains trace amounts of Gold, approximately 0.2 milligrams on average.

31Vestigial Traits

Vestigial Traits

There are a number of other vestigial traits in the human body other than the appendix, like muscles in our ears, wisdom teeth, tonsils, a stump of a third eyelid, and our coccyx (former tail).

32. The human body doesn't have a specific physiologic method for reducing iron levels. The only way to reduce body iron is to remove cells (such as bleeding).

33. At birth, a baby's eyes aren't developed enough to perceive color or depth. It usually takes about 6 months for their vision to reach adult levels.

34. Humans hear anywhere from 20 to 100 times faster than they can see. Therefore everything we perceive with our ears is coloring every other perception we have, and every conscious thought we have. The sound gets in so fast that it modifies all the other input and sets the stage for it.

35. Humans have eyebrows to keep our eyes clean, and clear from rain, sweat, and light.



One possible reason behind hiccups all day is when hair or something else in your ear touches your eardrum.

37. Wisdom teeth are virtually nonexistent in indigenous Mexicans.

38. The center of the eye only contains cones, the receptor responsible for color vision. This creates a second blind spot in low light. This explains why it's hard to see clearly when looking directly at objects in the dark.

39. We have taste buds not only on our tongues, but on our lips, our cheeks, the roof of our mouth, and the back of our mouth. That's why it can affect the taste of food when the roof of your mouth gets burned.

40. We have crystals in our ears that sense gravity and give you balance.

41Sore Throat

Sore Throat

A sore throat caused by acid reflux is often worse in the morning since acid from the stomach can enter the esophagus, back of the throat, and mouth (contributing to tooth erosion) during the night while you are sleeping

42. People with a lightly pigmented eye color are more sensitive to light than people with dark eyes.

43. One reason why our faces are asymmetrical is due to our sleeping patterns. Those who sleep on their side or stomach are more likely to have an asymmetrical face.

44. Stomach acid is strong enough to dissolve stainless steel in 4-5 days.

45. We blink approximately 14,000 times/day. That’s 23 mins of each day during which we spend our eyes closed other than when sleeping.