How much do you know about your body?

What is the most common blood type?

• AB-

• B-

• O+

Answer explanation

Few people have blood type B negative (about 5%), and even fewer have AB negative, which is the rarest blood type. The most common blood type is O positive. Approximately 36% of people have this type of blood.

How much do fingernails grow per month?

• 0.75 mm

• 1.5 mm

• 3 mm

Answer explanation

Finger nails grow at an average of about 36 millimetres a year, which is 3 millimetres in a month. That’s much faster than toe nails, which grow about four times more slowly – about 0.75 millimetres a month.

Where exactly is your heart?

• On the left of your chest

• In the middle of your chest

• In the middle of your chest, a bit to the left

Answer explanation

When people sing their national anthem, they often hold the left side of their chest, thinking that they are placing their hand over their heart. But in fact our heart is near the centre of our chest, just a little to the left.

How long are human intestines?

• 3.5 m

• 8.5 m

• 13.5 m

Answer explanation

The average length of the small intestine in adults is seven metres. The average length of the large intestine is one and a half metres, so that’s eight and a half metres in total.

How many bones do you have when you are born?

• 206

• 300

• 426

Answer explanation

As adults, we have 206 bones in our bodies, but we start life

with many more. We are born with nearly 300 bones, but as we grow, some of them join together, leaving us with 206.

How many hairs are there on the human scalp?

• 90.000 -150.000

• 150.000 -190.000

• 190.000 -250.000

Answer explanation

The blonder our hair, the more hairs we have on our scalp. Fair-haired people have on average 150,000 hairs, brownhaired people have 110,000, and black-haired people about 100,000. People with ginger hair have got the fewest: about 90,000 hairs.

What is the human body's biggest organ?

• liver

• brain

• skin

Answer explanation

Most people don’t think of their skin as an organ, like their

heart, kidney, stomach and liver. But that’s what it is. And it’s

the largest organ, by surface area and weight. The average brain weighs 1.3 kg and is the third largest organ in our body. The liver is also very large and weighs even more: on average 1.6 kg. But the surface area of skin on an average adult is between 1.5 and 2 m2, and it weighs on average 10.8 kg.

What is the average thickness of human skin?

• 1-2 mm

• 2-3 mm

• 3-4 mm

Answer explanation

The thickness of our skin varies from about 0.5 mm on our eyelids to 4 mm or more on the soles of our feet and on the palms of your hands. But on average it is 2–3 mm thick.

Where is the largest muscle in your body?

• in your bottom

• in yout thigh

• in you jaw

Answer explanation

Different experts have different opinions. Some say it is the masseter muscle in our jaw, which helps us chew our food. Others say it is the muscles in our thighs, which allow us to run. Other experts believe it is the gluteus maximus in our bottom and lower back, which holds our bodies upright. What is certain is that the largest muscle is the gluteus maximus, but it is impossible to say which is the strongest because they do such different things.