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Ask Dr. Universe Body and Brain
University Communications Network > Ask Dr. Universe > Body and Brain

What is the difference between B cells and T cells in the immune system? – Tanveer, 11, California

Dear Tanveer,

Everyone who heard your question agreed that it’s a sophisticated one. To get my paws around the answer, I talked with my friend Phil Mixter. He’s an immunology professor at Washington State University.

He told me all living things need to protect themselves from microbes that could make them sick. These are called pathogens. They can be bacteria, viruses, fungi or parasites.

“Almost every organism I can think of—from plants to animals and beyond—has a defense system to handle the possibility that another organism might sneak in,” Mixter said.

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How does sleeping charge us up?  -Joaquin, 10, Illinois

Dear Joaquin,

I love curling up under a pile of blankets at bedtime and waking up refreshed in the morning. You might be surprised to hear that scientists aren’t sure why sleep makes us feel that way.

I talked about how sleep works with my friend Marcos Frank. He’s a brain scientist who works in the Sleep and Performance Research Center at Washington State University.

“Without sleep, we do poorly on a lot of tasks, and our brains and bodies don't work as well,” Frank said. “But why is not entirely clear.”

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Why do you get acne? – Joey, 12, Illinois

Dear Joey,

Whether we call them pimples, spots or zits, acne is something most people experience. As many as 95% of people have some acne sometime. That’s nearly everybody.

I talked about acne with my friend Sarah Fincham. She has a clinical doctorate in nursing. She’s a nurse and a professor in the College of Nursing at Washington State University.

If you look at your skin, you’ll see tiny openings called pores. These pores connect to oil-producing glands under our skin. They’re called sebaceous glands, and the oil they make is called sebum.

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How does the brain transfer signals to each body part to move? Yulissa, 11, Virginia

Dear Yulissa,

Your brain weighs less than 3 pounds but has the power to move your whole body. That’s because it’s part of your nervous system.

Your brain and the spinal cord that runs down your back make up your central nervous system. You also have a peripheral nervous system made up of nerve cells. These connect your brain and spinal cord to all the other parts of your body.

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Dr. Universe: Why does time fly when we are having fun? – Isaac, 7, Australia

If you’re having a great time playing at the beach or camping with your family this summer, the day might zip right by. But the long drive to get to your fun destination might seem to take forever. To understand why time seems to change based on our activities, I asked my friend Alana Anderson, who just earned her Ph.D. at Washington State University. Anderson studies how people, especially babies and little kids, manage their behaviors and emotions. Read More ...

Dr. Universe: Why do we get sleepy when we study? - Sadaf, 12, Pakistan

Dear Sadaf,

Like many good students, you’ve probably noticed that when you study, especially late in the day, you feel sleepy. Scientists don’t know exactly why, but they have a few clues.

The human brain is packed with tens of billions of cells called neurons, which process and store information that helps us observe, understand and make decisions about the world.

My friend Hans Van Dongen, director of the Sleep and Performance Research Center and a professor of medicine at Washington State University, said you might think about neurons as workers in a huge company. Each neuron is an expert in a piece of information, and neurons work together to share what they know and build new connections in the brain.

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Dr. Universe: Why do we have toenails and fingernails? – Chloe, 12, Texas

Dear Chloe, Maybe you like to paint your toenails beautiful colors or admire the dirt under your fingernails when you come in from playing outside. But you’re right to notice that nails must be more than just decoration. To learn more, I talked to my friend Edward Johnson, an assistant professor of anatomy and physiology at Washington State University. Johnson reminded me that humans are primates, just like gorillas or orangutans. If you look closely at a primate’s hand or foot, you’ll see their nails look a lot like yours. They’re wide and flat at the ends of their fingers and toes. Read More ...

Dr. Universe: Why does sleep feel so short? - Brooklyn, 12

That’s a great observation. When my friend Ashley Ingiosi was a kid, she remembers how napping in the car during a four-hour drive to her grandparents’ house seemed to make the time fly by. Maybe you’ve had a similar experience. As a researcher at Washington State University, Ingiosi is really curious about what goes on within the human brain during sleep. She was happy to help with your question. Read More ...

Dr. Universe: What are cells made of? – Lela, 10, Bogart, GA

Dear Lela, You have all kinds of cells in your body that do lots of different things. In fact, there are about 200 different types of cells in the human body—from blood cells to skin cells to bone cells. To find out exactly what all those cells are made of, I visited my friend Deirdre Fahy. Fahy is a scientist at Washington State University who is curious about how and why things work, including our cells. She reminded me the human body is made up of billions of cells. You might think about each cell as if it were a tiny room. But this room, or cell, is so small, you’d likely need a microscope to see it. Read More ...

Dr. Universe: Why do we have to blink? - Michael and Virgil, 3 and 5, in Sioux Falls, SD

Dear Michael and Virgil, If you’ve ever had a staring contest with a friend, you may have felt your eyes start to get tired and dry. Eventually, you just had to blink. Blinking helps our eyes stay healthy, and my friend Dr. Karen Janout, a clinical assistant professor at Washington State University, told me all about it. She said that with each blink, your eyelids help spread tears over the surface of your eyes—and you actually do this a lot. Humans blink an average of 15 to 20 times a minute, which adds up to somewhere around 5.2 to 7.1 million blinks a year. Read More ...

Why are people most commonly right-handed? Who/what deicides if we are left-handed or right-handed? Are you left-handed or right-handed? Mya, 8, Alexandria, VA

We don’t know exactly why so many people are right-handed, but one place we might look for answers is in the material that makes a person who they are: genes. The genes in your body help control all sorts of things from the color of your hair to your skin to your eyes. These traits can be passed down through generations—from grandparents to parents to you. My friend John Hinz, who is a right-handed professor at Washington State University, knows a lot about genes and the study of how organisms pass their genes through generations. Read More ...

Dr. Universe: How does toothpaste clean your teeth? -Lucy, 10, Pullman, WA

Dear Lucy, If you are anything like me, every day you squeeze a little toothpaste onto your toothbrush and brush your teeth. Toothpaste gets its cleaning power from a few different ingredients. My friend Mark Leid was happy to tell us about how they work. Leid spent part of his career teaching future dentists. He is also dean of the Washington State University College of Pharmacy and Pharmaceutical Sciences. First, he told me the outer covering of a tooth is called enamel. It’s the hardest tissue in the whole human body—even harder than bone—and it helps with things like chewing your food. Read More ...

Dear Dr. Universe: I heard a little bit about how COVID-19 started, but I don’t know much about it. What happened?  - Colleen, 10, Louisa, VA 

It turns out scientists around the world are investigating this very question. It’s likely the coronavirus that causes COVID-19, SARS-CoV-2, started in an animal before jumping to humans. But exactly how it all happened is still a kind of mystery.      That’s what I found out from my friend Michael Letko, a researcher at Washington State University who studies viruses and how they cross different species. Read More ...

How does exercise help us? What is the best exercise?

When we exercise, it helps the body and mind in so many different ways. One important muscle that benefits from exercise is the heart. Maybe you’ve felt your heart beat harder and faster when you run or climb at the playground. As the heart gets stronger, it also gets better at pumping blood around the body. That’s really important because your blood is full of oxygen you need to help fuel all your body’s systems. That’s what I found out from my friend Chris Connolly, an associate professor at Washington State University who knows a lot about the science of exercise. Read More ...

Dr. Universe: Why do we have spines? - Jessie, 10, Covina, Calif.

Dear Jessie,

Your spine is more than just a long line of bones. It’s the secret to jumping for joy, the base for all your best dance moves. Every time you run, climb, walk, and play, your spine is right there with you.

“Without a spine, our ability to move would be completely different,” Edward Johnson said.  Johnson teaches Human Anatomy in the School of Biological Sciences at Washington State University. He is very curious about how all the parts of your body work together.

All creatures with spines are called “vertebrates,” including humans. They get this name from their vertebrae: the special bones that make up the spine. Your vertebrae are different shapes and sizes, but they all connect together.

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How do viruses form? Since the coronavirus has been all over the news, I've been wondering this question for a long time. - Samantha, 12, N.C.

Dear Samantha,

Viruses are strange things. They’re not alive like you or me. But they behave somewhat that way—spreading, growing, appearing in new forms. How can this be?

There’s a lot scientists don’t know yet about the new coronavirus. But they do know a lot about how viruses work and make people sick.

To learn more, I talked to Sylvia Omulo, a scientist specializing in infectious diseases at Washington State University.

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Dr. Universe: how do sleeping darts work? (e.g. for elephants) - Jonathan, 7, Pullman, Wash.

Dear Jonathan,

Some people get nervous when they go to the doctor. Maybe you’re one of them. You may not enjoy all of the visit, but you understand the doctor wants to help you. (And that a treat might await you at the end.)

But if an elephant gets sick, they can’t understand a doctor’s words. They may get confused and scared, until it’s too dangerous to help them.

That’s why sleeping darts—also known as tranquilizer darts—help so much.

“It’s safer for both the humans and the elephant because the humans aren’t right next to a wild animal, and the animal isn’t being chased to try to catch it,” Dr. Tamara Grubb said. She is a veterinarian at Washington State University who specializes in anesthesiology, drugs that make animals calm, sleepy, or unable to feel pain.

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Dr. Universe: Why do people have different fingerprints? - Mary, 12, South Carolina

Dear Mary,

Did you know even identical twins have different fingerprints? It can be hard to tell twins apart, but a close look at their fingertips can reveal who’s who. The reason lies partly in their genes, but mostly from the unique way everyone’s skin grows before birth.

That’s what I learned from my friend David M. Conley, a professor at Washington State University’s Elson S. Floyd College of Medicine.

“The reason fingerprints are unique is the same reason individual humans are unique,” Conley said. “Variation is the norm, not the exception.”

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Dr. Universe: Why are brains mushy? – First Graders, Waller Road Elementary, Puyallup, Wash.

Dear First Graders,

You’re right, brains are quite mushy. It turns out the three-pound organ between your ears is mostly made up of water and fat.

I found out all about brains from my friend Jim Peters, a neuroscientist at Washington State University.

“It’s gooey. It really is squishy,” he said. “When it is warm, it is kind of like butter.”

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Dr. Universe: Why do we have a tailbone? -Tyler, 15, East Liverpool, England

Dear Tyler,

At the very bottom of the human spine is a bone that sticks out a bit called the coccyx (cox-ix). We sometimes call it the “tailbone,” but it is actually made up of several different spinal bones.

In some animals that actually have tails, those different bones at the bottom of the spine help them move their tail around. But in humans, those bones partially fused together.

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Dr. Universe: Why do we have nightmares? -Kourtney, California,  10

You are running through the woods and a bear is chasing you, when all of a sudden you wake up in your bed and realize it was just a scary dream. Our nightmares can sometimes feel super scary, even if what’s happening isn’t real. Fear is a natural part of being a human. In fact, you may have even felt shaky or sweaty after waking up from a bad dream. It’s all part of something we call the fight or flight response. When humans are faced with something scary, this response helps them decide if they should face their fears and fight or run away by taking flight. This fight or flight response works even when you are asleep. Read More ...

Dear Dr. Universe: How do we talk? – Emmy, 7, Wash. State

Dear Emmy, When you were a little kid, maybe you played Peek-a-Boo or sang “Itsy Bitsy Spider.” These kinds of games and songs have a lot of the different sounds we make when we are first developing speech. A lot of humans start out playing with speech through cooing and crying. At about six months old, this cooing and crying turns to babbling. A baby might make sounds such as ma-ma, pa-pa, or ba-ba. Read More ...

Dr. Universe: Why are dogs important to humans? Stephani R., 9, Washington State

Dear Stephani, Dogs are important to humans in all kinds of ways. The connection between the two goes back thousands of years. A long time ago, wolves would trail along after humans on hunting trips and eat any scraps they could find. Eventually these wolves evolved into dogs that helped protect the hunters and gatherers. Read More ...

Dr. Universe: How do bags form under your eyes? –Sophia Ivy, 7, New Providence, NJ

Dear Sophia Ivy, If you’ve ever stayed up late and woke up really early, you may have noticed a little puffiness or swelling under your eyes. When I asked my friend Devon Hansen about the answer to your question, she said that we first have to know a bit about how sleep works. Read More ...

Dr. Universe: Why do we get morning breath? -Stephanie, 10

Dear Stephanie, If you’ve ever caught a whiff of someone’s stinky morning breath, or even your own, you know it can be pretty rotten. We can trace the smell back to tiny culprits that live in our mouths. They are called microbes and they live around your gums, between your teeth, and on your tongue. Read More ...

Dr. Universe: Why do we have a belly button? – Jane, 9, Kennewick, WA

Whether you have an innie or an outie, pretty much all us mammals have a belly button. But before you had a belly button, there was actually a different bit of anatomy in its place. While you were still growing inside of your mother, a small, bendy tube on your tummy connected the two of you. This tube is how you got pretty much everything you needed to grow before you were born into the world. Read More ...

Dr. Universe: Why do we have five fingers and five toes? -Eli, 11, Edinburgh, Indiana

Dear Eli, While humans may be one of the few animals that can give a high five, they are one of many with five fingers and toes. Humans are part of the primate family, which also includes monkeys, apes, and even lemurs. As a member of the family, you also have fingernails instead of claws and pads on your fingertips that help with your sense of touch. Read More ...

Dr. Universe: Why are there different blood types? - Sarah, Tacoma, Wash.

Dear Sarah,

At this very moment, several quarts of blood are circulating through your body at nearly 4 mph. But as you’ve pointed out, not everyone’s blood is the same.

Your question made me wonder exactly what we mean when we talk about blood types. I decided to ask my friend Amber Fyfe-Johnson, a researcher at Washington State University who studies cardiovascular diseases--diseases of the blood vessels-- in kids.

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Why do we have different feelings? - Charan and Aishwarya V., 10 & 8, Rutherford, New Jersey

Dear Charan and Aishwarya,

Imagine you are playing a game of soccer and your best friend is on the opposing team. The sun is out, you are having a great time, and you score the winning goal. You’d probably feel pretty happy and so would your team.

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Dear Dr. Universe: Do you know how human and animal interactions help our mind grow? Does it help us? Does it do nothing? This has fascinated me for a very long time. - Gabby G., 11, Berlin, VT

Dear Gabby,

Our brains are pretty busy. They are constantly thinking, feeling, and sensing our world. One thing that can help some people relax is spending time with an animal friend. You might play fetch with a dog, sit with a cat, brush a horse, or even watch a goldfish zip around its bowl.

People who spend a lot of time with animals might tell you that something special seems to be going on here. But scientists are looking for evidence and want to find out for certain just what is going on. They want to know … » More …

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Dear Dr. Universe: Why do we find some things scary? -Jack H., 8, UK 

Dear Jack,

While our fears might be different, we all get scared sometimes. Vacuums, dogs, and even cucumbers make my hair stand on end. Perhaps for you it’s spiders, the dark, or the thought of monsters under your bed.

My friend Michael Delahoyde is really curious about what freaks us out. As an English professor at Washington State University, he’s even taught a course about monsters.

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Are we getting lazier? -Aaryan, 9, Timber Ridge

Dear Aaryan,

We cats have a reputation for being lazy. We sleep a lot. But the truth is when I got your question, I didn’t know much about laziness. So, I decided to talk about it with a couple of psychologists here at Washington State University.

My first stop was the Psychology of Physical Activity Lab. That’s where I met up with my friend, Professor Anne E. Cox.

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Why is yawning contagious? -Grant, 10, Pullman, WA

Dear Grant,

When I got your question, I met up with my friend Hans Van Dongen, a scientist at Washington State University in Spokane. He works in a research lab where they study sleep. As a cat who appreciates naps, it’s one of my favorite places to visit.

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Dear Dr. Universe, Please answer this question: Do animals dream? What dreams do they get? I humbly request you to answer these questions. BYE! Or should I say MEOWY! -Prahlad R.

Dear Prahlad,

After a quick catnap and a stretch, I went to visit my friend Marcos Frank, a scientist at Washington State University who studies animal sleep.

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Why do we get jealousy? I can feel it sometimes, too, but I don't know why.  -Hailey, 10, London, Ontario

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Dear Hailey,

Cats love attention, but we don’t get jealous like humans do. It’s one of those emotions that set human beings apart from other creatures in the animal kingdom. But I can’t imagine it’s the most pleasant. The poet William Shakespeare once called jealousy a green-eyed monster. Still, it’s an emotion that can help you navigate the world.  

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