Kids’ brain glossary
The words we use, one line each. Characters are cartoons for real things, never a measurement of your kid.
- Adenosine (sleep pressure)Deno
- A chemical that builds up in the brain while we’re awake and creates sleep pressure, the need to sleep. Caffeine can block its message, which is why it makes tired kids feel awake.
- Say it to your kidDeno is sleep sand that piles up all day until it’s time to sleep.
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- AdrenalineAdri
- A hormone released by the adrenal glands for fast action. It makes the heart pound and the body ready to move. It is part of the fight-or-flight response.
- Say it to your kidAdri makes your heart pound so your body is ready to move fast.
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- AdrenarcheDea
- An early hormone step, usually around ages 6 to 8, when the adrenal glands start making hormones like DHEA. It can bring body odor or first hairs and is a normal part of growing.
- Say it to your kidDea is the first little signal that your body is starting to grow up.
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- AmygdalaMigo
- An almond-sized part of the brain that spots danger and strong feelings fast. Migo is the smoke detector that yells before the thinking part has time to speak.
- Say it to your kidMigo is the smoke detector in your head. Sometimes it rings when there’s just toast.
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- AutoplayLupi
- A feature that starts the next video by itself, so there is never a natural ending. Turning autoplay off gives your kid a stopping point.
- Say it to your kidLupi starts the next video before you can say stop. We turn Lupi off.
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- Bright light late at nightGlo
- Bright evening light turns melatonin down and can push sleep later. Little kids may be extra sensitive. Lamps low and warm after dinner help.
- Say it to your kidGlo is the flashlight in Mela’s face. Turn the lights down.
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- CaffeineKafi
- A stimulant in cola, iced tea, coffee and energy drinks that can keep a body awake for hours. Pediatricians advise against energy drinks for kids.
- Say it to your kidKafi keeps your body awake when it wants to sleep. No Kafi after lunch.
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- CerebellumBelu
- A part at the back of the brain that coordinates balance, movement and timing. It helps turn practice into smooth, automatic skill.
- Say it to your kidBelu keeps you balanced and helps your moves get smooth with practice.
- Circadian rhythmCirki
- The body’s roughly 24-hour rhythm that runs sleep, hunger and hormones. Light, meals and regular routines help keep it on time.
- Say it to your kidCirki is your inner 24-hour rhythm, like a clock that keeps your day in order.
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- Co-regulationDuo
- When a calm adult helps a child’s body settle down. Kids learn to calm themselves by first being calmed by someone else, many times over.
- Say it to your kidDuo is when you and I calm down together, until you can do it on your own.
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- CortisolCorti
- The body’s main stress hormone. It rises in the morning to wake the body and helps in real emergencies. It becomes a problem when the alarm keeps ringing and nobody helps turn it down.
- Say it to your kidCorti rings the alarm when there’s danger. It’s helpful, but it’s tiring if it never stops.
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- Deep sleep and REM sleepRemi
- Two kinds of sleep through the night. Deep sleep is linked to growth and recovery. REM sleep, when most vivid dreams happen, is linked to feelings and learning.
- Say it to your kidRemi takes you on a night tour: deep sleep to rest, dream sleep to sort the day.
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- Delay of gratificationPaci
- Being able to wait for something better later. It grows through the preschool years and depends on sleep, mood and how reliable the adults around are.
- Say it to your kidPaci is waiting now for something better later. It gets easier with practice.
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- DopamineDopa
- A brain messenger linked to wanting, effort and learning what pays off. It is not simply a “pleasure” chemical. Dopa is the character who hands out the gold stars.
- Say it to your kidDopa gives out gold stars when you finish something, so you want to try again.
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- Early school age (6 to 8)Skuli
- A time of school, rules and friends. Some kids notice body smell or first hairs, an early hormone step called adrenarche.
- Say it to your kidSkuli goes to school, learns the rules and makes friends.
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- Early teens (12 to 14)Sprouti
- A time of fast growth. The body clock shifts later and rewards feel bigger than ever.
- Say it to your kidSprouti is growing fast, sleeping late and feeling everything big.
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- EndorphinsEndo
- The body’s own relief messengers, released with effort, laughing and play. They are linked to feeling good after hard exercise or a big belly laugh.
- Say it to your kidEndo turns jumping and giggling into good feelings.
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- Executive functionExi
- The set of skills that includes working memory, impulse control and flexible thinking. They grow fast from about age 3 and keep developing into the twenties.
- Say it to your kidExi is your brain’s manager: remembering the plan, waiting and switching gears.
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- Fight-or-flightSimpa
- The body’s fast alarm response to a perceived threat. Heart rate and breathing speed up so the body can act. Slow breathing and a calm adult help it settle.
- Say it to your kidSimpa is the body’s gas pedal. It speeds up when something feels scary.
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- GABAGabi
- The brain’s main calming signal, which quiets other signals down. Think of it as the brake pedal. Gabi is the character who dims the lights after a big feeling.
- Say it to your kidGabi presses the brain’s brake and turns the volume down.
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- GhrelinGreli
- A hormone released by the stomach that signals hunger. When hunger goes unanswered, small problems can feel huge. That is the 5 p.m. “hangry” feeling.
- Say it to your kidGreli rings the hunger bell from your tummy.
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- Growth spurtSpurti
- A short stretch of fast growth, most noticeable in puberty. Appetite and tiredness often go up along with it.
- Say it to your kidSpurti makes your body grow fast, so you get hungry and sleepy.
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- HippocampusKampi
- A seahorse-shaped brain part that helps make new memories and files them, including during sleep. It is Kampi, the memory librarian.
- Say it to your kidKampi is the librarian who files today’s memories while you sleep.
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- Hormone
- A chemical messenger sent through the blood by a gland. Cortisol, melatonin and testosterone are hormones. They work more slowly than neurotransmitters and can affect the whole body.
- Say it to your kidHormones are body messages that travel in the blood to tell different parts what to do.
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- HypothalamusTala
- A small brain control room that helps manage hunger, thirst, body temperature and sleep, and directs many hormones through the pituitary gland.
- Say it to your kidTala is the control room that watches hunger, thirst and temperature.
- InsulinSuli
- A hormone made by the pancreas that moves sugar from the blood into the body’s cells so they can use it for energy.
- Say it to your kidSuli carries sugar from your blood into your cells, like a delivery truck.
- InteroceptionIno
- The sense of what’s happening inside your body: hunger, thirst, a full bladder, a racing heart. Kids are still learning to read these signals.
- Say it to your kidIno tells you what your body feels inside, like hungry, thirsty or nervous.
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- Irregular bedtimesLati
- Late bedtimes that change every night. In one large study, irregular bedtimes were linked to more behavior difficulties in young children.
- Say it to your kidLati makes bedtime jump around. A steady bedtime keeps your body clock happy.
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- LeptinLepi
- A hormone made by fat tissue that signals fullness to the brain. Along with ghrelin, it helps the body balance hunger and fullness.
- Say it to your kidLepi tells your brain when you’ve had enough to eat.
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- Master clock (suprachiasmatic nucleus)Tiki
- A tiny group of brain cells that works as the body’s master clock. It is set by light coming in through the eyes and keeps sleep and wake on schedule.
- Say it to your kidTiki is the body’s master clock. Morning light helps Tiki keep time.
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- MelatoninMela
- A hormone the brain releases in the evening as the light dims, telling the body that night is coming. Bright evening light turns it down. Ask a pediatrician before using melatonin products.
- Say it to your kidMela whispers “night is coming” so your body gets sleepy.
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- Mid teens (14 to 17)Seki
- Friends’ opinions matter most. The brain trims connections it doesn’t use and strengthens the ones it does, while the prefrontal cortex is still being built.
- Say it to your kidSeki cares what friends think and is figuring out who they are.
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- Middle childhood (8 to 10)Ruli
- Years of fairness, skills and hobbies. Logic works best on real, concrete things. In some girls the first signs of puberty start.
- Say it to your kidRuli loves rules that are fair and getting really good at something.
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- MyelinMili
- A fatty coating around nerve fibers that speeds messages up, like insulation on a wire. Myelination continues from childhood into the twenties.
- Say it to your kidMyelin is a speed coat for brain wires, so messages zoom instead of crawl.
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- NeuronRoni
- A nerve cell. Neurons carry messages through the brain and body as tiny electrical signals, passing them on with chemical messengers.
- Say it to your kidNeurons are the brain’s messengers, passing notes down the line.
- NeuroplasticityPlasti
- The brain’s ability to change with repeated experience. It happens all of life and is strongest in childhood, which is why small daily habits matter.
- Say it to your kidPlasti says your brain is like clay. What you practice, it shapes itself around.
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- Neurotransmitter
- A chemical messenger that carries signals between brain cells. Dopamine, serotonin and GABA are neurotransmitters. In our cartoons they are the Messenger characters.
- Say it to your kidNeurotransmitters are tiny messengers that run between brain cells with news.
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- NorepinephrineNora
- A messenger (also called noradrenaline) linked to alertness and attention. It helps the brain notice what matters right now. Nora is the character who switches on the spotlight.
- Say it to your kidNora switches on the spotlight so your brain notices what matters right now.
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- NotificationsPingi
- The pings and buzzes that pull attention off the task at hand. Every ping can drag the spotlight away from homework and back to the screen.
- Say it to your kidPingi pings and the spotlight jumps. Phone in another room.
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- OxytocinToci
- A hormone and messenger linked to closeness and trust. It is not a magic love potion. Its effects depend on the situation and the person.
- Say it to your kidToci builds the feeling of “I’m safe, I belong.”
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- Phone in the bedroomBedi
- A phone in the bedroom goes with worse sleep, even when nobody is using it. The pings, the light and the pull of one more look are all within reach.
- Say it to your kidBedi hides in the bedroom with the phone. Phones sleep in the kitchen.
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- Prefrontal cortexFronti
- The front part of the brain that plans, waits and stops impulses. It is one of the last parts to finish maturing, into the twenties, so kids borrow a parent’s calm.
- Say it to your kidFronti plans, waits and works the brakes. Fronti is still being built.
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- Preschool years (3 to 6)Whyzi
- The “why?” years. Imagination is huge, naps fade between ages 3 and 5, and waiting and following rules are just starting to grow.
- Say it to your kidWhyzi asks why about everything. That’s how a brain learns.
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- ProprioceptionPropi
- The sense of where your body parts are without looking. Muscles and joints report back, which is why heavy play like jumping and crashing can feel satisfying.
- Say it to your kidPropi knows where your arms and legs are, even with your eyes closed.
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- PubertyBloomi
- A chain of body and brain changes, started by a signal from the brain, that usually begins between 8 and 13 in girls and 9 and 14 in boys. Timing varies a lot.
- Say it to your kidBloomi is when your body starts changing into a bigger version of you.
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- Restraint collapse
- An informal parenting term, not a medical one, for a kid who holds it together all day at school and then falls apart with the safest person at home.
- Say it to your kidAfter a long day of being good, your battery runs out at home. That’s normal.
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- Self-regulationRegi
- The ability to manage your own feelings, impulses and attention. It grows slowly from toddlerhood through the teens and is built on years of co-regulation.
- Say it to your kidRegi is when you can calm your own body. It takes lots of practice.
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- Sensitive periodVindi
- A window when some skills, like vision, hearing and language, develop most easily. A window is not a deadline, and the brain keeps learning afterward.
- Say it to your kidVindi opens windows in your growing brain when some things are easiest to learn.
- SerotoninSero
- A messenger linked to mood, appetite, sleep and digestion. Most of the body’s serotonin is in the gut, not the brain. Sero is the character who opens the curtains and keeps the day steady.
- Say it to your kidSero opens the curtains in your head and keeps your mood steady.
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- SynapseSina
- The tiny gap where one neuron passes a message to the next. Connections that are used often tend to get stronger.
- Say it to your kidA synapse is a handshake between two brain cells. The more you practice, the stronger the handshake.
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- Synaptic pruningPruni
- The brain clearing out connections it doesn’t use and keeping the ones it does. It is strong in the teen years and is a normal part of growing.
- Say it to your kidPruni trims the brain’s garden so the paths you walk every day grow stronger.
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- TemperamentTemi
- A child’s inborn style: how active, cautious or intense they are. It is visible from babyhood and shapes how a child reacts, but it can be guided.
- Say it to your kidTemi is your own way of being: loud, quiet, bold or careful. All styles are fine.
- TestosteroneTeo
- A hormone that rises in puberty in both boys and girls, though much higher in boys. It helps build muscle, bone and energy. Hormones do not explain a teen’s whole mood.
- Say it to your kidTeo helps the body grow stronger and more energetic during the teen years.
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- ThalamusRelo
- A central brain relay that passes signals from the senses, like sight, sound and touch, on to the rest of the brain.
- Say it to your kidRelo is the switchboard that passes your senses’ messages to the right place.
- Theory of mindMindi
- Understanding that other people have their own thoughts, wants and knowledge. It usually takes shape around age 4, when kids start to notice that you don’t know what they know.
- Say it to your kidMindi knows that you’re thinking different things than I am.
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- Tween years (10 to 12)Tweeni
- Puberty starts for most girls and many boys, and friends start to matter more than they used to.
- Say it to your kidTweeni is in between: too big for little-kid stuff, not yet a teen.
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- Vagus nerveVagi
- The long main nerve linking the brain to the heart, lungs and gut. It is linked to calming down, and slow, steady breathing may help it along.
- Say it to your kidVagi is a long cable from your brain to your tummy. Slow breaths help it relax you.
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- Vestibular senseVesti
- The balance sense, run by the inner ear. It reports whether you’re moving, spinning or falling, which is why kids love swings and somersaults.
- Say it to your kidVesti is your balance sense. It tells you when you’re spinning.
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Educational content only, built on everyday habits. It’s not medical advice, a diagnosis or a treatment.