Catastrophic Cascades of Events
In Blood Circulation System
There is a phenomenon of Cascades of Events leading to catastrophic failures in systems with flow, flow of electric current, flow of blood, flow of water in plumbing system, etc.
Recent blackouts caused by deficiencies in various electric transmission systems are examples in case.
Problems can happen, when a part of the system is made suddenly unavailable for the flow - part of the grid is turned off, blockage in blood vessel, water valve is closed, etc. Artificially designed systems or bio-systems, which survived test of time, have built-in protection from rapid interruptions of flow. For example, in plumbing valves close slowly, that system can adjust and there is no hydraulic shock, which can break pipes and valves.
In addition, in well-designed systems, there is a buffer, which can absorb a sudden excess of energy in the system, when a part of it is cut off. In plumbing, it is an open tank on the roof, or a closed tank, which has air in it serving as a spring accumulating energy of water suddenly expending into it.
Absences of such fast reacting energy accumulating and releasing buffers in an electric grid inevitably leads to catastrophic chains of disconnections from the grid of its recipients by automatic systems, protecting energy recipients from energy overflow.
Problems in such systems arise from their hybrid nature - they are analog (continuous flow of liquid, electromagnetic energy, etc.) and they are discrete (blockages in plumbing cause change of state and shockwaves in the system, etc.). An unlucky change of the system state (temporary blockage of liquid flow, for example) can cause cascading effects (increased flow in other parts of the system and consequent temporary blockage).
This is a generic weakness of any hybrid system. A well-designed system compensates for this with a "buffer", which absorbs shocks. As long this buffer is efficient, cascading events dissipate fast, when it looses its efficiency, cascading events affect large portions of the system and could reach vital parts of it.
The Blood Circulation System has characteristics similar to plumbing or power distribution grid and it has similar problems.
The Blood Circulation System consists of:
The entire system is hydraulic-chemical-electromagnetic.
Hydraulic Pumps in a heart push and pull blood through blood vessels, some of which serve as a Distribution system for a Recipient (muscles, organs, etc.) or for a Gasses Exchange facility (lungs), other serve as a Collection system for the Recipient or the Gasses Exchange facility. The system moves oxygen and other chemical compounds. Electromagnetic field, pulsating in concert with Pumps, organizes the blood allowing its passing through the system with lower hydraulic pressures.
Pumps work by isolating a portion of liquid and making breaks in the flow of liquid and electromagnetic energy. This itself introduces discrete characteristics to the system in additional to occasional blockage.
In the Blood Circulation System, the buffer compensating for occasional increase in flow is in vessels.
From hydraulic point of view, blood vessels are elastic and expend and contract to absorb hydraulic shocks.
Scarring of vessels and insufficiently elastic artificial additions to vessels look beneficial, as long the view is limited to local effects, but they make this buffer inefficient and jeopardize the system as a whole.
Vessels work also as chemical buffers. Molecules in a bloodstream permeate walls of vessels when there is high concentration of them in the stream and move back into stream, when there is low concentration of them in the stream. This compensates for refusal of a part of the system to "consume" this type of molecule. Otherwise, it is possible to a cascade effect to emerge - refusal to consume in one part of the system causes increase of concentration of this type of molecule in the stream, and refusal to consume in adjacent part of the system due to excess of these molecules, and so on.
When vessels are saturated with cholesterol immobilized by macrophages, they are less efficient as chemical buffer and random chemical cascades emerge.
Regular mild stressing of the Blood Circulation System with physical exercise, sports, games, etc. should improve elasticity of vessels. Exercises leading to growth of muscle mass should lead to grows of new elastic vessels and creation new buffers in the system, where old once became ineffective.