Muscles

[Alban]

I have been reading a little on muscles and how they work ,they do seem very efficient at what they do. I was considering a diver in a squat position then standing up with his cylinders on his back , the forces required to lift him must be immense relating to the fulcrum points ? Would this even be possible to replicate with hydraulics or cables ?

Previously Dr Deco has mentioned the effect of viscous adhesion would this be the same as placing the palms of your hands together in the pool and pulling them apart causing bubbles ?
In a previous post on knuckle cracking there is a simple picture of this , would the bubbles formed in the capillaries be taken in to the venous supply ? Or would they also be formed in the tissues surrounding the capillaries ?

Thank you for your time Alban

 

[The Iceni]

Alban once bubbled...
Previously Dr Deco has mentioned the effect of viscous adhesion would this be the same as placing the palms of your hands together in the pool and pulling them apart causing bubbles ?

I don't believe it is. I think what you describe with the hands is cavitation. A rapid temporary reduction in pressure. I am not really sure I understand if this differs from viscous adhesion.

In a previous post on knuckle cracking there is a simple picture of this, would the bubbles formed in the capillaries be taken in to the venous supply ? Or would they also be formed in the tissues surrounding the capillaries ?

Yes. All capilliaries flow into veins.

However what you describe with the hands is an active event. When the muscle contracts down on itself is the active event within muscle tissue, when it relaxes the event is passive and therefore likely to be relatively slower and less violent but I strongly suspect micrunuclei will form in both muscle tissue itself and in the capilliaries, if only because of the energy released and the shock waves caused (remember the muscle pump and the difference in scale between climbing a ladder in heavy equipment and finning with neutral bouyancy).

However I have no evidence to quote you.

No doubt others will.

 

[Alban]

Thank you Dr T.

I can understand ( joke ) how the bubbles form in the venous but as I understand it ,this is not the real problem . Also will the capillaries be squeezed and as the blood flows through , this will create a low pressure " area ". Will this low pressure area be in the capillaries or extra vascular as you say.

The shock waves , is this like hitting the side of glass of cola ? The kinetic energy is enough to agitate the micronuclei ??
Sorry for my simple analogies

Thanks again Alban

 

[The Iceni]

Alban once bubbled...
Thank you Dr T.

I can understand ( joke ) how the bubbles form in the venous but as I understand it ,this is not the real problem.

Hi again Alban, It is a major problem when there is a right to left shunt as there is in at least 30% of the population.

Also will the capillaries be squeezed and as the blood flows through , this will create a low pressure " area ". Will this low pressure area be in the capillaries or extra vascular as you say.

As I understand it, the whole of muscle mass will have the same internal pressure, only when it relaxes will normal circulation resume as the pressure reduces below that in the arteries and arterioles. This is why you cannot actively contract a muscle forcefully for any length of time. The high pressures within it reduces its blood supply and it runs out of energy.

The shock waves , is this like hitting the side of glass of cola ? The kinetic energy is enough to agitate the micronuclei ??

That is how I understand it but I have no evidence whatsover to support this hypothesis. Time for a moderator to join in to fully explain viscous adhesion, perhaps?

 

[Dr Deco]

Dear Alban:

Viscous adhesion

There are several mechanisms by which hydrodynamic cavitation can occur. There are all lumped under the term hydrodynamic cavitation and include Reynolds cavitation (such as occurs on ship’s propellers and in the Guinness Widget ), and viscous adhesion (also called “tacky” adhesion and Stefan adhesion). The latter is also the method of tribonucleiation. [See also the ATTACHMENT and supplement in the ASK DR DECO appendix to this FORUM for more information. You access it at http://www.doctordeco.com/]

Hands in the pool

In actuality, this is a form of viscous (Stefan) adhesion, except that you could not actually move you hands fast enough in a water medium to form cavitation bubbles. This does occur on a small scale however. We see this when clicking our tongue and it helps tree frogs climb.

Shock waves

Shock waves might generate nuclei in the body. When we walk, each footfall creates a pressure wave in the body. Whether this can form the necessary pressure and rarefaction waves is not clear.

These bubbles form in the capillaries, and I believe that similar mechanisms also form them in tissues. This is not generally believed by other barophysiologists. Many of my colleagues would probably argue with me on this point.

Dr Deco :doctor: