Can You Beat the Average Person in an Anatomy Quiz?

Maria Trimarchi

Image: Shutterstock

About This Quiz

Does your toe bone really connect to your foot bone? And the knee bone to the shin bone? See how much you know about the basics of your body. (Hint: the "toe bone" does connect to the "foot bone," although they're not called that -- and it's not quite that simple.)

How many bones make up your skeletal system?

When you're born, you have 270 bones, but by the time you're an adult -- and some have fused together -- your body's skeletal system is made up of 206 bones, connected together by cartilage, ligaments and tendons.

How much blood circulates through the body?

About 5 to 6 quarts of blood are circulating throughout your body at all times, through a system of blood vessels that measure about 60,000 miles.

The femur and which bone join at your knee?

The femur, which is the longest bone in your body, joins up with the second-largest bone, the tibia -- also known as the shin bone. Together with the fibula, the tibia connects the ankle to the knee, and supports a big part of your body's weight.

Which is not one of the five vital organs your body needs for survival?

Of the 78 organs in your body, there are five that perform vital functions and are essential to your survival: the brain, heart, kidneys, liver and lungs.

How much of your brain do you really use?

Despite the long-standing rumor that humans only use 10 percent of our brains, it's actually a myth. In reality, we use our entire brain -- all 3.3 pounds of it.

Which is the body's largest organ?

Your skin, which provides the body's barrier against disease, ultraviolet light and other foreign invaders, is the body's largest organ. On average, the human body has 10 pounds of skin, with a surface area of 20 square feet.

Your central nervous system includes your body's spinal cord and what organ?

Your central nervous system includes your brain and your spinal cord. Together, the brain and spinal cord are how we interpret the world around us, and control all of our voluntary movements, like walking and involuntary movements, like blinking. The CNS is also the home of our thoughts and emotions.

Which is not part of your body's digestive system?

Your body's digestive system is made up of seven main organs, including the salivary glands in your mouth, your esophagus, to your stomach, and on to the small and large intestines, the rectum (technically part of the large intestine), and to the anus. Working together with your digestive organs are the liver, gallbladder and pancreas.

What is saliva made of?

While your saliva contains 99.5 percent water, the remaining .5 percent is packed full of electrolytes, like sodium and potassium, as well as enzymes, such as amylase and lipase, and antimicrobial agents, including secretory IgA and lysozyme.

Your scapula is commonly known as which bone?

The scapula, which we all commonly call our shoulder blade, connects the upper arm bone with the collar bone, with a complex system of muscles that are responsible for its movements.

Every minute of the day and night, your heart pumps more than a gallon of blood throughout your body. How big is it?

Your heart has a big job, pumping more than a gallon of blood throughout your body, but it may not be as large as you imagine it to be. In fact, it's just about the size of your closed fist.

Where are your kidneys located?

The bean-shaped organs come in a pair. You'll find your kidneys, one sitting on each side of your spinal column, at the back of the abdominal cavity, where your adrenal glands and other crucial organs are.

Which is the medical term for collarbone?

Your collarbone, medically known as the clavicle, is what connects your arms to your body while keeping your shoulder blades in place.

Which grows faster, fingernails or toenails?

If it seems your fingernails need more frequent attention than your toenails, you're not imagining it. Fingernails grow four times faster than toenails -- but neither, despite the rumor, keeps growing after death.

How fast can a human sneeze travel?

Next time someone sneezes near you, consider this: Each human sneeze travels up to 100 mph. That's fast compared to passing gas -- farts are known to travel at speeds up to almost 7 mph.

Everyone has a unique fingerprint. But humans also have unique prints where?

Your fingerprints -- and toes, too -- aren't the only unique prints you have on your body. The outer creases of your ear are yours alone, as are your lip prints. In addition, your teeth and your retinas, too.

What part of your body produces new blood cells?

Your body is constantly making new blood, and it produces new blood cells -- red blood cells, the white blood cells and platelets -- inside your bones. All of your red blood cells, about 60 percent of your white blood cells, and 100 percent of your platelets are made in your bone marrow.

What organ removes carbon dioxide from your body?

On average, an adult takes more than 20,000 breaths every day. Every time you exhale, you're exhaling carbon dioxide from your body -- and you can thank your lungs for that.

Which is part of your skeletal system, but aren't considered bones?

Your teeth are made of dentin and enamel, the strongest material in your body. They have a role in your digestion, and they're also part of your skeletal system -- although they aren't considered bones.

Which is the smallest bone in the human body?

The stapes is a stirrup-shaped bone, one of three very small bones found in your middle ear. And at just 2.8 millimeters long, it's the smallest bone in your body.

Your ears continue to grow through your entire life. So does which other organ?

Your ears and earlobes as well as your nose appear to get bigger as we get older. The problem? You can thank gravity for that.

How often does your skin's outer layer shed?

You can expect your outer layer of skin to shed, from head to toe, every 2 to 4 weeks. In total, that's about a pound and a half of dead skin sloughed off per year.

What's your blood made of?

Your blood contains more plasma than blood cells. About 55 percent of your blood's volume is plasma, which is a yellowish sticky liquid.

What substance is responsible for the color of your skin?

Melanin is made with melanocytes, and it's what gives your skin its color. Everyone has the same amount of melanocytes, give or take a little, which are found in the deepest layer of the skin.

Where does your body store urine?

Your kidneys remove waste from your blood, which forms urine. And the urine, through the ureters (tubes), flows into the bladder -- which can stretch to hold up to 2 cups of fluid.

On average, people with what color hair have the most strands?

On average, you have about 100,000 hairs on your head. But some hair colors have more strands than others. For instance, natural brunettes have about 140,000 strands of hair -- more than the 110,000 that natural blondes have. Redheads actually have the least amount of hair, with just about 90,000 strands (although red hair is the thickest). Everyone loses, naturally, up to 100 strands every day.

How many pairs of ribs does the human body have?

Your bony rib cage is made up of 12 pairs of ribs -- true ribs, false ribs and floating ribs -- and your sternum. It's what keeps your soft internal organs protected.

Which corrosive acid does your stomach use to break down the food you eat?

Your stomach makes about a gallon of "juice" that's made up of substances that break down food and absorb nutrients. Gastric juice contains enzymes, such as pepsin which breaks down protein, and acids, such as hydrochloric acid that breaks down food.

How many times a day does the average person pass gas?

Amazingly, 99 percent of a fart is made up of odorless gases -- it's the remaining sulfurous gases, including sulfide and methanethiol, that are to blame. And you pass them, on average, 14 times a day.

How many different bones make up an adult human skull?

An adult human's skull is made up of 22 bones, which are split into the bones of your cranium (the frontal bone, the parietal bones, the temporal bones, the occipital bone, the sphenoid bone and the ethmoid bone) and bones of your face.

Why is the hyoid bone unique?

The hyoid, a horseshoe-shaped bone, is the only bone in the body that isn't connected to another bone. Also known as the lingual bone, it's found in the neck, where it helps support the tongue, and helps you speak and swallow.

What percent of an adult's body weight is water?

Your skeleton makes up about 30 to 40 percent of your body weight, but more than half of your body is actually made up of water. You need almost a gallon of water (through food and drink) every day, and you start to feel thirsty once you've lost about 2 percent of your water.

What part of your body has no blood supply?

The cornea is part of your eye. Light is focused through it, and delivers information -- an image -- to your eye's retina. The cornea is unique because it has no blood supply. Instead, it gets its oxygen directly through the air.

What is the ecosystem living in the human gut called?

The human microbiome is made up of billions of beneficial bacteria, fungi and viruses. That's right -- beneficial. Altogether, your microbiome, in your intestines, weighs between 2 and 5 pounds.

Humans are born with 33 vertebrae, but once you reach adulthood how many do you have?

We're all born with 33 vertebrae, but by the time we reach adulthood some have fused together to create our tailbone as well as the back of the pelvis -- leaving 26: 7 cervical, 12 thoracic, and 5 lumbar, followed by 5 fused sacral vertebrae, and then the coccyx of 4 fused coccygeal vertebrae. After you turn 40, gravity's effect on cartilage can cause you to shrink anywhere between one-quarter to a full five inches every decade thereafter.

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