How does bronchus obstruction lead to hyperinflation?

Bronchusobstruction in Asthma en COPD leads to hyperinflation of the lung. Bronchusobstruction mainly leads to problems in exhaling instead of inhaling. I never understood this.

Because if bronchusobstruction exists, surely inhaling and exhaling must be equally problematic right? I will try to explain in this blogpost why bronchusobstruction mainly results in exhaling-problems.

Analogy:

Normal physiology of breathing:

To ventilate the lungs the lungs must expand (inhalation) en contract (exhalation) in a cyclical manner.

Inhalation: to expand the lungs the diaphragm contracts and pulls the base of the lungs downward. Increasing the volume decreases the pressure. This is according to Boyle’s law: P * V = constant.

During inhalation the pressure in the lungs are decreased because of thorax expansion. By expanding the thorax, you are also expanding the airways inside the thorax. Low pressure inside the thorax prevents the airways from collapsing.

Exhalation: allthough inhalation is an active process, exhalation is a passive process during rest. The lung consists of elastic tissue. Because of elasticity of the lung tissue, the lung constantly wants to contract. The lungs are like an elastic band that are stretched during inhalation and automatically contracts causing exhalation.Thus exhalation causes no physical energy and is considered passive.

 

 

 

If you are inhaling or exhaling, the inward force of elasticity of lung matches the outward force of the thorax. The volume of the lung becomes stable and this is called the Functional Residual Capacity of the lung. This is shown in the next image:

 

Thus, loss of elasticity of the lungs leads to worse lung contraction and worse exhalation.

 

During exhalation the pressure in the lungs are increased and the alveoli correctly and the airway pathologically are closed.

 

Dynamic airway collapse because of high-pressure active exhalation:

Active exhalation is done by using the abdominal muscles to force the diafraghm upwards and internal intercostal muscles. However, this maneuver also reduces the diameter of the bronchi, limiting the rate at which they can exhale.

  1. Loss of elasticity
  2. Dynamic airway collapse caused by 1.
  3. Loss of diaphragm function/curvature because of hyperinflation by 1.  and 2.

 

airflow-resistance

 

gimo73-f5

 

Extra-thoracic obstruction: (croup, epiglottis, trachea tumor): The trachea tends to collapse during inspiration below the site of obstruction during inspiration because pressures in the extrathoracic trachea fall below atmospheric pressure in the surrounding air.

 

Intrathoracic obstruction is most severe during expiration and is relieved during inspiration. Extrathoracic obstruction is

Diameter and Poiseulle’s Law

Diameter effect on resistance is quadratic. R=c L/D^4 (Poiseulle’s Law). Thus if you increase the diameter twice in size, the resistance will decrease with

Poiseulle

Maybe a possible nice analogy to explain gravity as spacetime curvature.

So:

First watch this great video by MinuteEarth:

A short explanation of gravity in General Relativity is usually given as follows:

  • Mass tells spacetime how to curve, curved spacetime tells mass how to move.

This is actually wrong, since Mass is not the (only) thing that dictates spacetime curvature, but actually 4-momentum-flow! Mass is just one of the 4-momentum-flows! There are actually 16 flows, or actually 10 because of the symmetry of the Stress-Tensor.

For rivers it goes like this:

  • The waterflow in Rivers follow the spatial curvature of the landscape, and the the wateflow carves out the landscape changing its spatial curvature.

Does 4-momentum flow ‘carve out’ spacetime just like the River flow ‘carves out’ the landscape?

The underlying driving force of rivers is obviously gravity and going downhill. The underlying driving force of 4-momentum flow is actually …. entropy!

 

Some general bullshit I found on an old pc

General thoughts:

Difference of heat and work is minimized in entropy? Analogous to difference of kinetic energy and potential energy?

Quantum mechanics literally originated from a lightbulb moment, a dude name Max Planck was thinking how he could maximize the energy output of a lightbulb. He realized that the distribution of emitted colours and the intensity of those colours made bad predictions. He had to alter the distribution.

Is the lagrangian not actually about finding the smallest difference between the slope of an angle and the differance in distance between the jumps?

What if you make a small line segment and rotate it around a point, while calculating the lagrange of it around at all those points?

Why doesn’t light dissipate as heat, just like everything? Because it is heat

No aether needed because light is particles. Actually nothing needs an aether because of fields.

But quantum theory shows us that not only do electromagnetic waves display some properties of matter, but “matter” (e.g. elec-trons, protons, etc.) may be represented by waves of a field. In the end, only fields exist, distributed over space and at the same time shaping that space (or more accurately, space-time).

Thus, the phenomena of time dilation and length contraction are manifestations, in different reference frames, of the same phenomenon. They are the same, just like magnetism and electricity and space and time itself.

Is there also an action associated with space, such as S=L dx instead of S=L dt

What would happen if we go at lighstpeed?

One of the striking features of the phenomena of time dilation and length contraction is that both become catastrophic when the relative speed of the frames of reference is c. In this case all time intervals are dilated to infinity, which is to say that nothing happens! On the other hand, all lengths are contracted to zero, which implies that there is no finite world for things to happen in anyway. These comments are pertinent to the famous question which Einstein purportedly asked himself when he was a 15-year old schoolboy, a question which, he said, set him on the train of thought which was to culminate in the special theory of relativity: what would the world look like if one could travel on a beam of light? The answer appears to be that time and space would cease to exist.

Because of the equivalence of gravitational and inertial masses, it is a logical consequence of this statement that energy also is a source of gravitational fields. This fact creates the complications of Einstein’s theory of gravitation, with which we shall deal later. All fields, including the gravitational field, contain energy. The energy of the gravitational field can be the source of more gravitational fields. This situation sharply distinguishes the gravitational field from the electromagnetic one. The sources of the electromagnetic field are charges, but charges do not produce more charge. Electromagnetic fields are not themselves charged, and thus cannot produce further electromagnetic field

Is space isotropic inside an event horizon? No? Angular momentum?

Entropy:

This energy is disordered in that it is the energy of incoherent motion; because the motions are as likely to be in one direction as another, no work can be done using them. Heat motion carries net kinetic energy, but no net momentum because momentum is a vector. This is why heat energy cannot be utilized.

Since heat appears to be more or less inadvertently produced in all energy transformations in which it is used to do useful work for specific purposes, to what extent can heat energy itself be exploited to do such work? This question attracted the attention of Sadi Carnot (1796-1832), eldest son of Napoleon’s ministry of war. He wrote down in 1823 for the first time in history the Second Law.

The motive power of heat is independent of the agents employed to realize it; its quantity is fixed solely by the temperature of the bodies between which it is effected — by the transfer of caloric.

Important question in thermodynamics:How can we make a continually working machine?

A difference in temperature has made it possible for the system to do work

Entropy vector:

The ratio of kinetic energy of a bunch of molecules versus the net direction of the other three momentum vectors is the entropy.

The capability to do work is in the ith direction is  p,i/|E|

Carnot cycle:

How can we make a continually working heat engine?

Start with a flywheel attached to a gas chamber with a piston.

State 1: Equilibrium, no motion.

State 2: Gas chamber gets heated, piston will move to the right, work gets done on the wheel.

What happens at the end of the stroke, i.e. when the wheel is completely to the right? The flywheel will do work on the gas chamber. When there is no heat loss or friction, this work will equal the

Incoherent motion is absolute.

On entropy and order:

Something that is “ordered”, or “orderly”, is not disordered or random. Randomness is the converse of order. What do we mean, for example, by saying that the positions, or the motions, of the molecules of a gas are random? We mean that the positions and motions of the molecules are as likely to have any value as any other. The state of any molecule is independent of the states of any other; there are no correlations between them. (We must remember, however, that the equal probability of all configurations is subject to obvious macroscopic constraints; all gas molecules stay in the container, and their total energy is fixed.)

Because of the accuracy of the statistical physics of macroscopic phenomena, we find ourselves in a strange situation: we understand the macroscopic world if we discard all microscopic information. It is precisely the impossibility of explaining the macroscopic world in terms of microscopic determinism that makes it appear deterministic. We have come a long way from Laplace’s mechanistic model of the physical world. Quantum mechanics will take us even further in revealing the element of chance at the core of things, in the behaviour of matter at the atomic and subatomic levels.

The heat of an object divided by its entropy is its temperature.

Two systems: 1 & 2. They exchange energy.

System 2 to system 1. For each system: dS=dQ/T,

The heat flow in an object divided by the temperature of that object will be its change in entropy.

 

 

Entanglement

So:

A PET-scan is done by placing a positron-emitting material inside a light detector. The positron interacts with a nearby electron and they both produce two high-energy light particles. Because of conservation of momentum they both have to travel in opposite directions. Thus at the same time the circular light-detector around this material will find a particle at opposite sides. Both these photons are entangled, because if we only measure one on one site we immediately know which direction the other one went. So I first thought that only those two things were entangled. However a whole sphere with at its center the positron-electron annihilation is entangled and expanding with the speed of light.

The best way to visualise what is happening BEFORE photon detection is to see a quantum mechanical spherically symmetric wave expanding out of the annihilation and the detecter eventually collapsing that wave to two points. All the locations are entangled with each other at the surface of the sphere, because not only does the opposite part need to know to show a particle, all the other points on the surface of that sphere have to ‘know’ to NOT show a particle. I hope that makes sense.

The gif is a bit what I mean: http://www.rakeshkapoor.us/ClassNotes/HTMLFiles/Waves-II_1-Animate.gif

Not only are two particles entangled, but the whole surface of that sphere is inherently entangled.