Gehirn
14 cards from across every topic, each citing a source. Tap one to open it in the feed.
- Breathlessness isn't caused by lack of oxygen.
The urge to breathe comes mainly from carbon dioxide: chemoreceptors in your brainstem sense how CO2 lowers the pH of …
- Dopamine isn't a pleasure chemical, it's a surprise signal.
In 1997 Wolfram Schultz recorded dopamine neurons in monkeys. They fired at unexpected juice. Once a light reliably …
- During sleep, your brain rinses itself out.
The brain tissue itself has no lymphatic vessels. Instead the brain pumps cerebrospinal fluid through the tissue and …
- Four letters that save minutes in a stroke.
FAST: Face – ask them to smile, does one side droop? Arms – raise both arms, does one drift down? Speech – repeat a …
- How your brain notices you're short of water.
Osmoreceptors in the hypothalamus measure the salt concentration of your blood. If it rises by just 1 to 2 percent …
- Most of your brain cells aren't in your cerebrum.
Your brain contains about 86 billion neurons, not the 100 billion long claimed. The distribution is the surprise …
- Nicotine fits a lock that was built for something else.
Your brain uses the messenger acetylcholine for attention and muscle commands. Nicotine resembles it so closely that it …
- The organ that creates pain cannot feel any itself.
Your brain tissue has no pain receptors. That is why surgeons can keep patients awake during some operations: only …
- There are no left-brained and right-brained people.
In 2013 Nielsen and colleagues scanned the resting-state networks of over 1,000 brains. They found no individuals whose …
- Yawning doesn't add oxygen. Here's why you still do it.
The textbook story is refuted: breathing air richer in oxygen does not reduce how often you yawn. Today's leading …
- You don't sleep one night, you sleep five short ones.
Your sleep runs in cycles of about 90 minutes, typically 4 to 6 per night. Each cycle moves from light sleep through …
- You don't use 10 percent of your brain. You use all of it.
Imaging shows activity across all brain regions, including during sleep. The brain is about 2 percent of body weight …
- Your brain has its own border control with bouncers.
The blood–brain barrier arises because the cells lining brain capillaries are sealed by tight junctions, wrapped by …
- Your brain runs on the power of a dim light bulb.
The brain weighs about 1.4 kilograms, roughly 2 percent of your body, yet uses around 20 percent of your resting …