Fun Facts about Anatomy & Physiology Alan D. Morales, LAT, M.Ed. Athletic Trainer

Skeletal System A human has a bone just after the spine ends, which helps proves that humans once had tails (possibly). 25% of a human’s bones are in its feet. The only bone in the human body not connected to another is the hyoid. The longest bone is "FEMUR" or "THIGH BONE. The smallest bone is "STAPES" present in middle ear ENAMEL teeth) is the hardest part of our body.

Muscular System It takes 17 muscles to smile, 43 to frown and 47 muscles to STARE. The largest muscle in our body  is the Gluteus. Jaw muscles can provide about 200 pounds of force to bring the back teeth together for chewing. The human body has over 600 muscles, 40% of the body’s weight. The longest muscle in the human body is the Sartorius. Human bodies produce 70 kg of ATP (a molecule that stores energy, permitting us to do nearly everything the body does) per day.

Integumentary System 10% of human dry weight comes from bacteria. A fingernail or toenail takes about 6 months to grow from base to tip. A human being loses an average of 40 to 100 strands of hair a day. An average human scalp has 100,000 hairs.

Integumentary System Blondes have more hair than dark-haired people. Each square inch of human skin consists of twenty feet of blood vessels. Every square inch of the human body has an average of 32 million bacteria on it. Fingernails grow faster than toenails. Fingerprints serve a function - they provide traction for the fingers to grasp things.

Integumentary System Humans shed about 600,000 particles of skin every hour - about 1.5 pounds a year. Humans shed and re-grow outer skin cells about every 27 days. The largest human organ is the skin, with a surface area of about 25 square feet.

Nervous System A human head remains conscious for about 15 to 20 seconds after it is been decapitated. A human’s scent membrane in the nose is about the size of a postage stamp. If you go blind in one eye, you’ll only lose about one-fifth of your vision (but all your depth perception).

Nervous System The human brain is about 85% water. There are 45 miles of nerves in the skin of a human being. NERVES can send impulses at a speed of 360 km/hr. NOSE can smell 2000-4000 different smells. Ears can detect 1500 different sounds. HUMAN EYE can detect 10,000 colors. You can visualize a 200 degree wide angle. The maximum amount of times we blink a day is about 30 minutes.

Circulatory System An individual blood cell takes about 60 seconds to make a complete circuit of the body. By the time you turn 70, your heart will have beat some two-and-a-half billion times The most common blood type in the world is Type O. The rarest, Type A-H.

Circulatory System There are four main blood types: A, B, AB and O and each blood type is either Rh positive or negative. Blood types in the US: O positive ~ 38.4% O negative ~ 7.7% A positive ~ 32.3% A negative ~ 6.5% B positive ~ 9.4% B negative ~ 1.7% AB positive ~ 3.2% AB negative ~ 0.7%

Circulatory System There are 60,000 miles of blood vessels in the human body. The HEART pumps 27949.3 liters of blood every day.

Respiratory System A cough releases an explosive charge of air that moves at speeds up to 60 mph. A sneeze can exceed the speed of 100 mph. The left lung is smaller than the right lung to make room for the heart.

Urinary System An average human drinks about 16, 000 gallons of water in a lifetime. An average person uses the bathroom 6 times per day. Lab tests can detect traces of alcohol in urine six to 12 hours after a person has stopped drinking. The HEART and KIDNEY are the only parts in our body which never rest.

Digestive System 1.7 liters of saliva is produced each day. A healthy individual releases 3.5 oz. of gas in a single flatulent emission, or about 17 oz. in a day. A person will die from total lack of sleep sooner than from starvation. Death will occur about 10 days without sleep, while starvation takes a few weeks.

Digestive System Every person has a unique tongue print. The small intestine would stretch to a length of 22 feet. In a lifetime the average US resident eats more than 50 tons of food and drinks more than 13,000 gallons of liquid. STOMACH produces 2 liters of HYDROCHLORIC ACID every day.500,000 cells of stomach’s inner walls are replaced every minute so that acid does not damage the walls.

Reproductive System At age seventy, 73% of men are still potent. The average duration of sexual intercourse for humans is 2 minutes. According to the Kinsey Institute, the biggest erect penis on record measures 13 inches. The smallest tops off at 1 3/4 inches. Most men have erections every hour to hour and a half during sleep. The male fetus is capable of attaining an erection during the last trimester. Semen contains small amounts of more than thirty elements, including fructose, ascorbic acid, cholesterol, creatine, citric acid, lactic acid, nitrogen, vitamin B12, and various salts and enzymes.

Reproductive System The average bra size today is 36C. Ten years ago it was 34B. Women who went to college are more likely than high school dropouts to enjoy both the giving and receiving of oral sex. Humans are the only species on earth that have face-to-face sex.

Reproductive System Babies are born with 300 bones, but by adulthood we have only 206 in our bodies. One in every 2000 babies is born with a tooth. Pregnancy in humans lasts on average about 270 days (from conception to birth). A fetus acquires fingerprints at the age of three months. The largest cell in the human body is the female ovum, or egg cell. The smallest cell in the human body is the male sperm.

Endocrine System Laughing lowers levels of stress hormones and strengthens the immune system. The glands of the endocrine system and their secretion (or the hormones they produce) influence cell and function of our body. Glands in endocrine system secrete major hormones directly in the bloodstream. Important glands of endocrine system include: hypothalamus, pituitary, thyroid, adrenals etc.. The hormones (which are often called chemical messengers) that are released by glands in endocrine system are very crucial to regulating different systems of our body including our mood and growth. I think there are more than 20 major hormones which are secreted by glands in endocrine system. Endocrine system controls the body processes that happen slowly, like cell growth. Glands from this system form signaling pathways. (endocrine signaling?)

Lymphatic System The lymphatic system returns about 3.17 quarts (3 liters) of fluid each day from the tissues to the circulatory system. The lymphatic system is made up of lymph vessels that carry lymph, a protein-rich fluid that is transported through the lymph vessels, and lymph nodes which filter out germs and toxins. There are over 100 lymph nodes throughout the body, with the majority of them being located in the neck, groin and armpits. Within the lymphatic vessels, lymph is transported through the vessels and moves via the squeezing action of their neighboring skeletal muscles.

Other Interesting Facts 11% of the world is left-handed. 1 out of every 113 people in the world will die in 2007. About 10,000,000 people have the same birthday as you. Every time you lick a stamp, you’re consuming 1/10 of a calorie. Humans have 46 chromosomes, peas have 14 and crayfish have 200.

Other Interesting Facts On average women say 7,000 words per day. Men manage just over 2000. The human body has enough fat to produce 7 bars of soap. It is impossible for most people to lick their own elbow. (try it!). TWO BILLION BODY CELLS wear out and are replaced everyday.