Nerven
7 cards from across every topic, each citing a source. Tap one to open it in the feed.
- How rubbing a bump makes it hurt less.
Pain travels to the spinal cord along thin, slow nerve fibres. Touch uses thick, fast ones. Both meet at the same relay …
- How your heart beats without orders from the brain.
In the right atrium sits the sinoatrial node, a cluster of cells that discharge electrically on their own about 60 to …
- Pruney bath fingers aren't water damage.
The old story was that skin soaks up water and puckers. But fingers with severed nerves don't wrinkle at all. Wrinkling …
- The knee-jerk reflex simply bypasses your brain.
The tap on the patellar tendon stretches the muscle, a sensory neuron reports it to the spinal cord and synapses …
- Why a heart problem can show up in the left arm.
Pain fibres from organs and from skin converge on the same nerve cells in the spinal cord. For the heart, the cell …
- Your fastest nerves outrun a high-speed train.
Thickly myelinated fibres conduct at up to 120 metres per second, about 430 kilometres per hour. Unmyelinated C fibres …
- Your gut wall holds more nerve cells than your spinal cord.
The human enteric nervous system contains some 500 million neurons – roughly five times the spinal cord's estimated 100 …