Explain how a carotid choke works.

[W. Rabbit]

I think it's important to point out it's not really accurate to say it's a circulatory OR nervous effect when in fact the passout effect (syncope) is the result of a feedback loop involving both (a systemic effect).

We're talking about an effect that is occurring in two separate systems that feed into each other (circulatory and nervous) simultaneously, not one after the other, from a SINGLE external force (neck strangulation).

Applying the proper neck pressure in the right spot is essentially causing a big disagreement with those two systems, and the time you spend asleep is the time it takes for them both to normalize.

Otherwise you get into the "chicken and egg" argument of what comes first, constricted arteries and HIGHER blood pressure OR baroreceptors/vagus response and the resulting LOW PRESSURE, when in fact these are atomic events (i.e. they happen at the same time). So it makes sense for creativo to say "pressurizing the neck restricts bloodflow" because that is correct, but not the sole reason for syncope because that effect can only come when both the nervous and circulatory responses to strangulation "kick in".

So putting this in science-ey terms:

• More physical pressure on the neck arteries = high BP = faster vagus response = (low BP) + (baroreceptorized, poor oxygen content blood) = sleep

• Closer physical pressure to vagus/sinus = faster vagus response = (low BP) + (baroreceptorized, poor oxygen content blood) = sleep

Reasoning:

High blood pressure causes the vagus response, which is to lower pumping rate of the heart rapidly (and thus pressure). You can get a blood pressure drop and syncope from having generally high blood pressure, or just COUGHING HARD. The vagus is what tells your heart not to explode while it tries to pump all that blood around your (now pressurized) circulatory system.

"hey buddy there's some congestion up ahead...you might want to slow down for a minutes...that's right...lay back...try to enjoy this..."

Local blood pressure around the vagus definitely plays a role, everyone can (hopefully) see from the diagrams that the vagus connects right into the arteries. So the closer constriction is to the vagus, the more effective the choke.

[money]

Is it *required* to apply pressure to both sides of the neck to elicit a vasovagal response?

The other night in class we were drilling an arm triangle from guard. A couple times I ended up trapping their arm up against my neck and half-strangling myself to get the choke. While uncomfortable to me, it wasn't enough that I couldn't continue and get them to tap.

So my totally uneducated answer would be that it requires both.

[Uncle Skippy]

both sides of the carotid bifurcate to left and right side, internal and external carotid arteries which feed both the facial and cerebral arteries, thus a choke to either the left side or right side are essentially cutting off approximately 1/2 of the blood flow to the brain

Right, but my reason for asking that was to see if compressing the vagus nerve on one side can cause someone to lose consciousness. If the primary cause of loss of consciousness is due to stimulation of the vagus nerve, can it be done on only one side?

[Snake Plissken]

Right, but my reason for asking that was to see if compressing the vagus nerve on one side can cause someone to lose consciousness. If the primary cause of loss of consciousness is due to stimulation of the vagus nerve, can it be done on only one side?

I think, anatomically, it would be nigh-impossible to apply pressure to the nerve without having affecting the artery.

[wetware]

Right, but my reason for asking that was to see if compressing the vagus nerve on one side can cause someone to lose consciousness. If the primary cause of loss of consciousness is due to stimulation of the vagus nerve, can it be done on only one side?

I'm thinking that's what happens when someone goes out from a kick or hard ridgehand to the neck. (I only use those two examples because those are the only ones I've seen happen. I'm sure it could happen with being punched or elbowed, too) I doubt the amount of displaced blood is enough to cause the whole process.

[Snake Plissken]

I'm thinking that's what happens when someone goes out from a kick or hard ridgehand to the neck. (I only use those two examples because those are the only ones I've seen happen. I'm sure it could happen with being punched or elbowed, too) I doubt the amount of displaced blood is enough to cause the whole process.

then you have three factors in play:
temporary restriction or disruption of airflow through the trachea
temporary restriction or disruption of bloodflow through the common carotid
temporary disruption of synapse to the primary organ (heart or brain) of the neural fibres through the vagus nerve

[jnp]

That last part is something I can attest to occurs during vasovagal syncope...immediately after nearly/partially passing out from it, I felt an intense euphoria, orgasmic, in fact. That is not an embellishment at all, in fact it's in line with the research referenced earlier on women reaching orgasm through the vagus nerve ONLY. Those nerves near the carotid (vagus and sinus) sure seem to be keys to maintaining the body's conscious state.

For the record, I've been choked unconscious well over a dozen times and I've never woke up with a feeling of euphoria. Instead, it's, "Why am I sleeping in the mat?".

Then again, based on the description, I'm pretty sure I've never experienced vasovagal episode during a choke being applied.

[Colin]

I've never been unconscious from submission before, but I'm pretty certain I've been close a few times. The room starts to get smaller and smaller.

[W. Rabbit]

Then again, based on the description, I'm pretty sure I've never experienced vasovagal episode during a choke being applied.

That could be because of conditioning over time, or just your personal physiology. Euphoria is a commonly reported symptom hence the feinting game fad, but it probably differs greatly with body chemistry.

Why wouldn't you have experienced vasovagal response, since it's part of everyday (non-judo) strangulation?

[henno]

I have come across the theory of restricted blood flow out of the head causing high blood pressure and then unconsciousness before and thought it made sense.

Arteries (which take blood away from the heart) are generally deeper within the body, while the veins which return it to the heart are shallower. Being shallower, the veins can be more easily restricted by external pressure, unlike the deeper arteries.

When you put a tourniquet on a limb, you can see and feel the higher pressure as more blood is pumped in than can easily get away. Try it on your finger. It quickly gets pumped up and red. A bit like the look of a guys face undergoing a tight RNC (the tourniquet in this case).

I've been looking at some anatomical images of the neck on the net. It's a bit hard to tell what the difference in depth is between the jugular vein and the carotid artery. Either way, veins are thinner and more flimsy tubes than arteries which is another factor that makes them easier to restrict with external pressure.