50 Question Challenge #16, The Human Body: answers and sources

Scores: 0-19: Curious patient · 20-29: Med student · 30-39: Doctor · 40+: Body genius. Don't forget your Couch Wager. Spotted a mistake? Email hello@ahaville.com with the question number.

Level 1: Easy

1. 1

   Let's start easy. Which organ pumps blood around your body?

   The heart An adult's heart is about the size of a fist.

   Source: my.clevelandclinic.org/health/body/21704-heart · nhlbi.nih.gov/health/heart/anatomy · wikipedia.org/wiki/Heart

2. 2

   Which organs fill with air when you breathe in?

   The lungs Tiny air sacs inside pass oxygen into your blood.

   Source: nhlbi.nih.gov/health/lungs/respiratory-system · wikipedia.org/wiki/Pulmonary_alveolus

3. 3

   Which bones form a cage around your heart and lungs?

   The ribs Most people have 12 pairs of them.

   Source: my.clevelandclinic.org/health/body/rib-cage · wikipedia.org/wiki/Rib_cage

4. 4

   What does your skull protect?

   Your brain A baby's skull has soft spots, so it can grow with the brain.

   Source: my.clevelandclinic.org/health/body/skull-sutures · wikipedia.org/wiki/Fontanelle

5. 5

   Where are most of your taste buds?

   On your tongue They sit in the tiny bumps on your tongue.

   Source: informedhealth.org/how-does-our-sense-of-taste-work.html · wikipedia.org/wiki/Taste_bud

6. 6

   What does your pupil do in bright light?

   It gets smaller It's really a hole into your eye.

   Source: my.clevelandclinic.org/health/body/24317-pupil-of-the-eye · wikipedia.org/wiki/Pupil

7. 7

   Which part of your body has a drum inside it?

   Your ear Sound makes your eardrum vibrate.

   Source: nidcd.nih.gov/health/how-do-we-hear · wikipedia.org/wiki/Eardrum

8. 8

   What connects your muscles to your bones?

   Tendons Ligaments join bone to bone instead.

   Source: my.clevelandclinic.org/health/body/21738-tendon · my.clevelandclinic.org/health/body/21604-ligament · wikipedia.org/wiki/Tendon

9. 9

   What bendy stuff gives the tip of your nose its shape?

   Cartilage Your outer ears are shaped by cartilage too.

   Source: my.clevelandclinic.org/health/body/23173-cartilage · ncbi.nlm.nih.gov/books/NBK558970/ · wikipedia.org/wiki/Cartilage

10. 10

    Last easy one: which teeth usually come in last?

    Wisdom teeth Some people never get any at all.

    Source: my.clevelandclinic.org/health/body/23223-wisdom-teeth · wikipedia.org/wiki/Wisdom_tooth

Level 2: Body sayings

1. 11

   Which body saying is this? 🍬🦷

   A sweet tooth It means you love sweet food.

   Source: dictionary.cambridge.org/dictionary/english/sweet-tooth

2. 12

   And this one? ❤️🥇

   A heart of gold It means someone is very kind.

   Source: dictionary.cambridge.org/dictionary/english/heart-of-gold

3. 13

   Which saying? 🥶🦶

   Cold feet It means getting nervous about something you'd planned.

   Source: dictionary.cambridge.org/dictionary/english/get-cold-feet

4. 14

   Name this saying. 🟢👍

   A green thumb It means you're good with plants. In the UK: green fingers.

   Source: dictionary.cambridge.org/dictionary/english/green-thumb

5. 15

   Which body saying? 💰💪🦵

   An arm and a leg If it costs an arm and a leg, it's very expensive.

   Source: dictionary.cambridge.org/dictionary/english/arm-and-a-leg

6. 16

   And this one? 🦅👁️

   An eagle eye It means you notice every little detail.

   Source: dictionary.cambridge.org/dictionary/english/eagle-eye

7. 17

   Which saying is this? 🦶🚪

   A foot in the door It means a first chance to get into something.

   Source: dictionary.cambridge.org/dictionary/english/get-a-foot-in...

8. 18

   Name this one. 🐱👅

   Cat got your tongue? People ask it when someone suddenly goes quiet.

   Source: dictionary.cambridge.org/dictionary/english/has-the-cat-g...

9. 19

   Which saying? 💪🧈

   Elbow grease It means hard work, like scrubbing.

   Source: dictionary.cambridge.org/dictionary/english/elbow-grease

10. 20

    Last saying! ✋🍪

    Hand in the cookie jar It means getting caught doing something you shouldn't.

    Source: dictionary.cambridge.org/us/dictionary/english/get-caught...

Level 3: Quick: doctor words

1. 21

   What is your clavicle?

   Collarbone

   Source: merriam-webster.com/dictionary/clavicle · wikipedia.org/wiki/Clavicle

2. 22

   What is your sternum?

   Breastbone

   Source: merriam-webster.com/dictionary/sternum · wikipedia.org/wiki/Sternum

3. 23

   What is your scapula?

   Shoulder blade

   Source: merriam-webster.com/dictionary/scapula · wikipedia.org/wiki/Scapula

4. 24

   What is your mandible?

   Lower jawbone

   Source: merriam-webster.com/dictionary/mandible · wikipedia.org/wiki/Mandible

5. 25

   What is your tibia?

   Shinbone

   Source: merriam-webster.com/dictionary/tibia · wikipedia.org/wiki/Tibia

6. 26

   What is your hallux?

   Big toe

   Source: merriam-webster.com/dictionary/hallux · wikipedia.org/wiki/Hallux

7. 27

   What is your pollex?

   Thumb

   Source: merriam-webster.com/dictionary/pollex · wikipedia.org/wiki/Pollex

8. 28

   What is your axilla?

   Armpit

   Source: merriam-webster.com/dictionary/axilla · wikipedia.org/wiki/Axilla

9. 29

   What is your trachea?

   Windpipe

   Source: merriam-webster.com/dictionary/trachea · wikipedia.org/wiki/Trachea

10. 30

    What is your thorax?

    Chest

    Source: merriam-webster.com/dictionary/thorax · wikipedia.org/wiki/Thorax

Level 4: Records and surprises

1. 31

   At what time of day are you tallest?

   In the morning The discs in your spine squash a little during the day.

   Source: pubmed.ncbi.nlm.nih.gov/4002039/ · pubmed.ncbi.nlm.nih.gov/8009352/ · wikipedia.org/wiki/Intervertebral_disc

2. 32

   What color is the blood in your veins?

   Dark red Veins only look blue through your skin.

   Source: health.clevelandclinic.org/what-color-is-blood · wikipedia.org/wiki/Vein

3. 33

   Which part of your tongue tastes sweet things?

   All of it The old “tongue map” was a mistake.

   Source: informedhealth.org/how-does-our-sense-of-taste-work.html · wikipedia.org/wiki/Tongue_map

4. 34

   By its weight, which is the body's strongest muscle?

   The jaw muscle On the back teeth, a bite can reach about 200 pounds (90 kg).

   Source: loc.gov/everyday-mysteries/biology-and-human-anatomy/item... · wikipedia.org/wiki/Masseter_muscle

5. 35

   Which of these has no blood vessels at all?

   The cornea It takes in oxygen from the air, through your tears.

   Source: my.clevelandclinic.org/health/body/eyelids · wikipedia.org/wiki/Cornea

6. 36

   Which organ can grow back after part of it is removed?

   The liver That's why a living person can give part of theirs.

   Source: my.clevelandclinic.org/health/body/21481-liver · my.clevelandclinic.org/departments/transplant/programs/li... · wikipedia.org/wiki/Liver_regeneration

7. 37

   About how much blood does your heart pump in a day?

   About 2,000 gallons That's about 7,500 liters.

   Source: texasheart.org/heart-health/heart-information-center/topi... · wikipedia.org/wiki/Cardiac_output

8. 38

   How tall was the tallest man on record?

   8 ft 11 in Robert Wadlow of Illinois measured 2.72 m in 1940.

   Source: guinnessworldrecords.com/world-records/tallest-man-ever · wikipedia.org/wiki/Robert_Wadlow

9. 39

   About how long does a red blood cell live?

   About 4 months Your bone marrow keeps making new ones.

   Source: medlineplus.gov/blood.html · wikipedia.org/wiki/Red_blood_cell

10. 40

    Last one of this level: why is it so hard to tickle yourself?

    Your brain expects the touch It predicts the touch and turns the feeling down.

    Source: pubmed.ncbi.nlm.nih.gov/10943682/ · wikipedia.org/wiki/Tickling

Level 5: Impossible

1. 41

   In 1628, who first fully described how blood circulates?

   William Harvey He was the doctor of England's King Charles I.

   Source: britannica.com/biography/William-Harvey · wikipedia.org/wiki/William_Harvey

2. 42

   What is the scientific word for a hiccup?

   Singultus Babies hiccup even before they're born.

   Source: my.clevelandclinic.org/health/diseases/17672-hiccups · wikipedia.org/wiki/Hiccup

3. 43

   What is your philtrum?

   The groove above your lip The spot between your eyebrows is the glabella.

   Source: dictionary.com/browse/philtrum · wikipedia.org/wiki/Philtrum · wikipedia.org/wiki/Glabella

4. 44

   What is the pale half-moon at the base of a fingernail called?

   The lunula Its name is Latin for “little moon.”

   Source: dictionary.com/browse/lunula · wikipedia.org/wiki/Nail_(anatomy)

5. 45

   What is the longest muscle in the human body?

   Sartorius It runs from your hip to the inside of your knee.

   Source: my.clevelandclinic.org/health/body/21936-thigh-muscles · wikipedia.org/wiki/Sartorius_muscle

6. 46

   In 1901, who discovered the main blood groups?

   Karl Landsteiner He won a Nobel Prize for it in 1930.

   Source: nobelprize.org/prizes/medicine/1930/landsteiner/facts/ · wikipedia.org/wiki/Karl_Landsteiner

7. 47

   Which of these is a bone in your wrist?

   The scaphoid Each wrist has 8 small bones.

   Source: my.clevelandclinic.org/health/body/25060-anatomy-of-the-h... · wikipedia.org/wiki/Scaphoid_bone

8. 48

   What is the white of your eye called?

   The sclera Its name comes from the Greek word for “hard.”

   Source: etymonline.com/word/sclera · wikipedia.org/wiki/Sclera

9. 49

   Which sense tells you where your arms are with your eyes closed?

   Proprioception It's why you can touch your nose with your eyes shut.

   Source: my.clevelandclinic.org/health/body/proprioception · wikipedia.org/wiki/Proprioception

10. 50

    The very last one: which is moved only by muscles outside it?

    Your fingers Muscles in your palm and forearm pull them with tendons.

    Source: my.clevelandclinic.org/health/body/25060-anatomy-of-the-h... · wikipedia.org/wiki/Finger

The Big Aha stories

• The doctor who rolled up paper: In 1816, a Paris doctor named René Laennec had to listen to a patient's heart. Pressing his ear to her chest didn't feel right. Then he remembered a simple fact about sound: put your ear to one end of a wooden beam, and you can hear a pin scratch the other end. So he rolled some paper into a tube. One end on her chest, the other at his ear. The heartbeat came through clearer than ever. He went on to make wooden tubes, and named his invention the stethoscope. In 1819, he wrote the whole story down in his book. Sources: ncbi.nlm.nih.gov/pmc/articles/PMC1570491/ · britannica.com/biography/Rene-Laennec · wikipedia.org/wiki/René_Laennec · wikipedia.org/wiki/Stethoscope
• The glow that showed bones: In November 1895, in Würzburg, Germany, Wilhelm Röntgen was testing a glass tube wrapped in black cardboard. Nearby in the dark lab, a screen coated with a special chemical began to glow. Something invisible was getting through the cardboard. Weeks later he made a famous picture of his wife Anna Bertha's hand. You can see her bones, and her ring. He called the rays X-rays, because they were unknown. In 1901, he won the very first Nobel Prize in Physics. Sources: nobelprize.org/prizes/physics/1901/rontgen/biographical/ · britannica.com/biography/Wilhelm-Rontgen · wikipedia.org/wiki/Wilhelm_Röntgen · wikipedia.org/wiki/X-ray

Bonus question

About how many hairs does a person normally shed in a day? We reveal the answer in the pinned comment under the video.