TED have a fantastic animation that explains how pain works and how it is relieved by two common analgesics – aspirin and ibuprofen.
Of course, pain relievers work in many different ways – the opioids, for example, are vastly different – but the four-minute video is a wonderful guide to the neuroscience of two common household pills.
Excellent stuff.
Link to ‘How Do Pain Relievers Work?’ (via @brainpicker)
Mind Hacks 
Aside from the ironic porcupine analogy, great video. I found the compounds in stinging nettle to be interesting – who would have thought serotonin and acetylcholine could be a source of pain?