What’s the physiological difference between being unconscious, and just being asleep?
In: Biology
Asleep = the restaurant is closed to customers but the staff can still be working inside to prep for opening.
Unconscious = the restaurant is closed to customers and the normal staff went home so the cleaning team can do their work.
Being unconscious would generally mean your brain isn’t working as it should, and is an absence of wakefulness generally caused by pathology (lack of oxygen, stroke, psychiatric) Fainting/coma would fall under this category.
Sleep is regulated by our circadian rhythm driven by a specific portion in the hypothalamus. This portion (called the suprachiasmatic nucleus) affects our arousal state. The absence of wakefulness here is a controlled and metabolically distinct process and can be affected by environment (like light)
They are the same thing. Being knocked unconscious is kind of a misnomer. You are unconscious, but that is your brain powering down to protect itself, usually from being sloshed against the inside of your skull. Passing/blacking out is similar, depending on the cause. If your blood sugar plummets or you get choked out, your brain shuts your body down to conserve oxygen for itself.
The main difference between those and sleep is sleep is a prolonged state, whereas for the others you regain consciousness as soon as homeostasis (ie: blood flow to the brain, usually) is restored.
In this case sleep would probably be most accurately described as a category within the larger category of unconsciousness.
When you have passed out from oxygen deprivation (eg. Drowning, ill-advised adolescent sleepover games, circulatory dysfunction), in a coma, under anesthesia, or asleep, you are unconscious.
I like the business metaphor above but I will tweak it a bit. Awake is the business during normal operating hours, sleep is when everybody goes home and the cleaning crew comes in, a coma (in some cases) is the building being shut down for an extended period while construction crews do major repairs. Oxygen deprivation would then be “the building is on fire!” And everybody was evacuated.
Extended oxygen deprivation is well…the building didn’t survive the fire. At that point you get to take your pick on where all the employees went.
source: undergrad neuro degree
If you fall asleep and someone wakes you hours later your brain is aware if the passage of time and you are groggy but aware that you just woke up.
Personal experience here. I went in for surgery and the doctor put me under. I awoke in the recovery room hearing my wife talk to someone. I clearly remember wondering what my wife was doing in the operating room. During this the brain itself is unaware of events and the passage if time.
Latest Answers