Is A Brain Dead Person Actually Dead?

On TV you hear the term vegetive state and coma and brain death all the time in medical shows. But what do these terms actually mean? Hey brainiacs, Trace here for DNews. For non-medical people, the terms “vegetative
state,” “coma,” and “brain dead” are used interchangeably, but they’re not
synonymous and there are very important distinctions. People in a vegetative state still have a
functioning brain stem, meaning their body is on autopilot. They can breathe on their own, have a sleep-wake
cycle, and react to some stimuli. But they can’t hold a conversation or take
in their environment. Neurologists define consciousness by wakefulness
and awareness, and people in a vegetative state are awake but unaware. People in a coma, on the other hand, are not
awake or aware. Comas can happen either if the their cerebral
hemispheres aren’t working or if the Reticular Activating System, the part of their brain
stem responsible for wakefulness, is damaged. They enter a state of deep unconsciousness,
like the most hardcore nap ever taken. Still under the surface their brain is, at
a minimum, sending out some signals. It’s possible to recover from a coma into
a vegetative state and then regain awareness. Unfortunately it’s also possible to progress
from a coma to a state where all neural activity ceases and the brain no longer has any input
on the body’s functions. This is brain death. Brain death has another name in the medical
community: death. Someone in a vegetative state or coma is still
considered alive. But brain death is irreversible, so doctors
go through a series of tests known as the brain death examination before officially
determining that a person is in fact brain dead. These tests look for any brain function, even
the most basic brainstem reflexes. If the patient fails them, they are legally
dead. Sure they can have the semblance of life thanks
to life support, which in this context takes on an ironic name. But a brain dead person cannot live long without
assistance. Pacemaker cells in a person’s heart can
continue to function independent of the brain for up to a week, meaning blood keeps pumping. But the brainstem is responsible for keeping
breathing going. Even when you’re not thinking about it,
your brain is regulating your breathing, though I bet you’re all thinking about it now. Complete cessation of neural activity means
even that basic function of operating the lungs stops. Within minutes CO2 levels in the blood will
be fatal. A person in a coma would reflexively gasp
for air, but a brain dead person would not.The brain regulates a host of other functions
unconsciously too, like body temperature and blood pressure. And it is in charge of hormones that control
your metabolism, immune system, and specific organs like your kidneys. Keeping a person’s body going after brain
death requires a ventilator, blankets, and hormones. That’s a lot of outside effort to handle
the most basic work of meatball between your ears. It makes you appreciate everything that little
guy is up to. Thanks brain! Your brain is pretty vital for that whole
staying alive thing. So how much of it can you lose and still not
die? Julian covers just how much of your brain
is expendable here. What else would you like to know about the
brain? Let us know in the comments down below and
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