--- title: The human body deeper: the brain and nerves — a lesson of Mova's school · trees and pragmatics description: «The human body deeper: the brain and nerves», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Your brain is a soft, wrinkly organ about 1.4 kilograms in an adult, made of about 86 billion nerve cells, each linked to thou --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / The human body deeper: the brain and n… # The human body deeper: the brain and nerves Lesson 260 of the biology course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/260-human-body-deeper-the-brain-and-nerves/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/0/) — Your brain is a soft, wrinkly organ about 1.4 kilograms in an adult, made of about 86 billion nerve cells, each linked to thousands of others; together they make more connections than there are stars in our galaxy. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/1/) — Nerves are the body's wires: messages race along them, the fastest at about 120 metres a second, from your skin to your brain and from your brain to your muscles. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/3/) — You use all of your brain, not just 10 percent as some films say; different areas do different jobs, like seeing, moving, speaking and remembering, and the brain is busy even while you sleep. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/4/) — In cartoons like Tom and Jerry, Tom gets bonked on the head, sees stars and birds spinning round, and is fine a second later; a real hard knock can shake the brain, which is called concussion, and needs rest and a doctor. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/5/) — A reflex is a quick action where the message goes to the spinal cord, which sends the order straight back without waiting for the brain, saving a fraction of a second. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/6/) — The adult brain weighs about 1.4 kilograms and has about 86 billion nerve cells, each connected to thousands of others. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/8/) — Brain scans show that we use all parts of the brain, though not all at once, so the «10 percent» idea is a myth. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/9/) — Memories get stronger when you repeat them, sleep helps fix them as the brain replays the day, and spacing practice over several days works better than cramming. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/10/) — The left half of the brain controls the right side of the body and the right half controls the left, because nerves cross over in the brainstem, the stalk that joins the brain to the spinal cord. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/11/) — The idea that some people are «left-brained» and others «right-brained» is a myth; both halves work together. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/12/) — Sitting on a nerve squashes it and stops its messages for a while, and the tingle of pins and needles is the nerve waking up; moving the leg about helps it wake. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/13/) — The eye sees, but the brain guesses what it is seeing and can be fooled, as in optical illusions; it even fills in the blind spot where the nerve leaves each eye. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/14/) — You cannot tickle yourself because your brain predicts the feeling of your own fingers and makes it weaker; tickling needs surprise. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/15/) — The brain floats in fluid inside the hard skull, and a helmet spreads and softens a blow; after a hard knock to the head you should rest and see a doctor. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/16/) — Brains change as you learn, which is called plasticity, especially fast in childhood; London taxi drivers who learned all the streets were found to have a bigger memory area. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/17/) — You blink about 15 to 20 times a minute to wet and clean your eyes, the brain hides each dark moment, and staring at screens makes people blink less. - [18](https://md.mova.elamur.ai/free/en/corpora/school/biology/260-human-body-deeper-the-brain-and-nerves/18/) — Fat wraps fast nerves like insulation on a wire, and a stubbed toe hurts in two waves: a sharp first pain and a slower dull ache, because the two messages travel along different nerves at different speeds. - ← previous: [The microscopic world: tardigrades, mites, plankton and other tiny creatures](https://md.mova.elamur.ai/free/en/corpora/school/biology/259-the-microscopic-world-tardigrades-mites-plankton-and-other-tiny-creatures/) - next →: [The human body deeper: the heart and blood in amazing numbers](https://md.mova.elamur.ai/free/en/corpora/school/biology/261-human-body-deeper-heart-and-blood/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)