65 Fascinating Facts About The Human Body

Seeing the Bodies…The Exhibition in New York last November reminded me of how fascinating the body I inhabit is.

Featuring over 200 actual human bodies and specimens, meticulously dissected and respectfully displayed, the exhibition provides an intimate and informative look deep inside the systems of the body: Skeletal, Muscular, Nervous, Respiratory, Digestive, Urinary, Reproductive, Circulatory and the Treated Body.

Organizers used a revolutionary process called polymer preservation to permanently preserve the specimens. Through this process, all human tissue has been replaced with liquid silicone rubber. This prevents the natural decay process, making specimens available for study for an indefinite time period.

The exhibition is a great place to explore the wonders of the human form. As I walked from room to room, contemplating the specimens, I couldn’t help but take notes. Here are 65 facts about the human body.

Skeletal System

1. Our skeleton contains approximately 206 bones.
2. Children’s bodies grow faster in the springtime.
3. Babies have 300 bones, adults have 206.
4. Bone is a matrix of hard minerals built and maintained by bone cells. If you removed the minerals and kept the cells, you could tie your bones in a knot.
5. Bone is five times stronger than mild steel.
6. Bones make up only 14% of our total lean body mass.
7. The marrow inside certain bones of the adult skeleton creates about 2.5 million new red blood cells each second.
8. While standing, the bones of the foot lock together to form an unmovable pedestal. When walking begins, the bones unlock and change the foot into a mobile system of levers.

Muscular System

9. There are three types of muscle tissue: skeletal, cardiac and smooth.
10. Skeletal muscles move and support the skeleton. They make up about 50% of a person’s body weight.
11. There are 20 muscles in the foot that give it its shape and contract to relax and impart movement.
12. A stunning array of muscles, sometimes four layers deep, work together for bodily support and movement.
13. The muscles that run along the spine are some of the most powerful muscles of the body; they keep us upright and provide the strength for lifting and pushing.
14. Muscles produce heat to help maintain body temperature.
15. The largest muscles in your body are those in your buttocks.
16. The body’s smallest muscles are found in the ears; they are attached to the body’s smallest bones.
17. If all the muscles in your body worked together, you could lift more than 10 tons.
18. Every bodily movement and function – from breathing and digestion to running at top speed – depends upon the muscular system.
19. Muscles attach to bones via the tendons, which are often 500 times stronger than muscle and act to prevent strained muscles from tearing.
20. The most active muscles in the body are located in the eye.

If all the muscles in your body worked together, you could lift more than 10 tons.

Sensory System

21. The human body is made up of approximately 100 billion nerve cells or neurons.
22. The brain and spinal cord make up your central nervous system. All other nerves comprise the peripheral nervous system.
23. The brain’s right cerebral hemisphere governs artistic ability.
24. The brain’s left cerebral hemisphere is the center of logic and language.
25. Weighing only 1.4 kg in an average adult, the brain contains upwards of a trillion nerve cells, which are in constant communication with each other and the body. Some brain cells make connections with over 10,000 others in a split-second.
26. The cerebral cortex – gray matter – is responsible for the brain’s higher functions, such as thinking, speaking and storing memories. In fact, most of the information processing in the brain occurs in the cerebral cortex.
27. The total area of the brain is too large to fit in our uranium, so the cerebral cortex consists of folded bulges (gyri) that create deep furrows (sulci). The folds in the brain add significantly to its surface area, increasing the amount of gray matter and the amount of information we can process. It also gives the brain its “wrinkled” appearance.
28. Each of us has a unique wrinkled pattern.
29. Every person has a unique tongue print.

Nervous System

30. Faster than the world’s most powerful computer, the human nervous system uses billions of interconnected nerve cells to regulate all of the body’s vital fictions while also serving as the seat of all thought and feeling.
31. The adult spinal cord is roughly 45 centimeters long.
32. The limb system is a group of interconnected brain structures involved with different behaviors: the hippocampus, the amygdala, the seal area and the hypothalamus.
33. The hippocampus is an area buried deep in the forebrain that helps regulate emotion and memory. The hippocampus doesn’t just file away memories; it also connects related memories and gives them meaning.
34. The amygdala, which is located directly in front of the hippocampus, has a strong link to the olfactory system and is essential to the expression of emotions.
35. The seal area is a tiny region above the amygdala that is thought to be a pleasure and reward center and may be important in addictive behavior.
36. The hypothalamus, which is connected to all parts of the limit system, regulates the activity of he body’s organs and is responsible for the visceral changes due to the emotions, such as increased blood pressure.

Respiratory System

37. The alveoli are tiny air sacs within the lungs where the exchange of O₂ and CO₂ takes place. Each lung contains 300 million alveoli – if stretched out they’d cover a football field. The total surface area of the lungs is equal to a tennis court.
38. The lungs are actually divided into 20 functionally separate regions which receive their own blood supply and continue to operate if another segment is removed, this ensuring that breathing will continue if one region of the lung becomes diseased.
39. We speak by pushing air from the lungs into the larynx and vibrating the vocal cords. The more the vocal cords are stretched, the higher the pitch of your voice.
40. On average, a pack of cigarettes takes 3 hours and 40 minutes off your life.

On average, a pack of cigarettes takes 3 hours and 40 minutes off your life.

Digestive System

41. On average, adults have 22 feet (6.7 m) of small intestine, 5 feet (1.5 m) of large intestine.
42. To gain 1 pound (0.5 kg) you must consume 3,500 more calories than your body can burn.
43. To lose 1 pound (0.5 kg), you must burn 3,500 calories more than your body needs.
44. The heaviest single organ in the body, weighing close to 1.6 kg in an average adult, the liver is the largest organ inside the body as well as the one of the most important.
45. The liver is also the only organ that can regenerate itself in as much as 75% of the liver can be removed and it will still grow back to the same shape and form.
46. Gut theory stipulates that the gut organs of our ancestors used to be larger and required more space and energy. With evolution, the body began to divert more energy to the brain as it rapidly expanded, forcing the gut organs to become smaller and more efficient.
47. Humans eat far more meat than any other primate, which in turn has reduced the size of the human body’s digestive system.
48. The brain consumes between 20-30% of the calories you need.

Reproductive System / Urinary System

49. Every day, a person’s kidneys process about 200 quarts of blood to sift out 2 quarts of waste products and extra water.
50. The actual removal of wastes in the kidneys occurs in tiny units inside the kidneys called nephrons. Each kidney has about 1 million nephrons.
51. Though females are born with all the eggs they will ever have, men continue to produce sperm throughout their lives. The average healthy male produces between 1,500 and 3,000 sperm every second.

Fetal Development

52. Beginning life as a zygote in a single fertilized cell – the human body develops into a remarkably intricate system made up of an estimated 75-100 trillion cells.
53. After conception, everyone spends one half hour as a single cell. By the 11th week, all major organs have formed. The heart of an embryo begins to beat during the 5th week.
54. Human growth is divided into two stages: embryonic and fetal. Embryonic stage begins at conception and continues until week 8. It is characterized by rapid growth in which the external features of the embryo form.
55. Week one of the fetal stage begins around the 9th week after fertilization and ends at birth (which marks the 28th or 30th week of fetal growth). It is characterized by the development of the major organs and the systems of the body.
56. Fetal cells may remain within the mother decades after birth, helping her fight disease and stay healthy.

A heart beats roughly 100,000 times a day.

Circulatory System

57. No cell in the body lies more than a few kilometers from a blood vessel.
58. There are 100,000 miles (160,934 km) of blood vessels in the human body.
59. Pulse is an artery wall stretching with each heartbeat.
60. Every drop of blood in the body passes through the heart once per minute.
61. The brain requires 20% of the body’s total blood supply.
62. Blood’s red color comes from the hemoglobin in red blood cells, which turns red when it binds with oxygen.
63. A heart beats roughly 100,000 times a day.

Treated Body

64. Nerve cells create electrical impulses that reach speeds exceeding 270 miles per hour.
65. Many prosthetic implants are no longer solid but contain a honeycomb arrangement of open spaces coated with bone cells. This helps implants fit more securely into the existing bone.