Fun fact 5 of 10
5. The brain cannot feel pain
Brain tissue has no pain receptors. That is why, in some surgeries, the patient can stay awake and talking while doctors operate on the brain.
What feels it is what surrounds it
Pain starts in nerve endings called nociceptors, which alert the brain when something hurts the body. The curious part is that the brain itself, which receives all these alerts, has no nociceptors in its tissue.
The membranes that wrap the brain, the blood vessels, the muscles and the skin of the head do have these endings. Headaches come from these surrounding structures, not from the brain itself.
This makes surgery with an awake patient possible. With anesthesia in the skin and bone, the person stays conscious while the team operates and asks them to speak, count or move a hand. This way the doctors confirm, in real time, that they are not hitting areas important for speech or movement.
Even without feeling pain, the brain is a demanding organ. It makes up about 2% of body weight, but consumes around 20% of the energy we use at rest.
Staying awake also helps map each patient's brain. The exact position of language areas varies somewhat from person to person, and stimulating a point with a weak current while the patient speaks shows the team where they must not go.
Você sabia? O cérebro de um adulto pesa em torno de 1,3 a 1,4 quilo e tem cerca de 86 bilhões de neurônios, número estimado em 2009 por uma equipe da Universidade Federal do Rio de Janeiro.
