I will attempt to to reduce this question to the simple, because I am a simpleton...
In A&P School and advanced flight training I would get stuck on just actually what happens inside a jet engine. A&P books had a simple formula called 2+2. There were two formulas of jet thrust. They are F=MA + P x A That's how a jet engine works. Force = Mass times acceleration and at the exit nozzle it's pressure x area.
Now as to pressure inside the engine it is not immediately apparent but the highest pressure in a jet engine is at the outlet of the last stage of compression. This is the entrance to the combustion section.
Now we all know that if we build a fire in a closed are the pressure will go up. So how come the pressure ahead of the combustion chamber is higher than the pressure in the combustion are itself? It's because the area of the combustion chamber is larger than the minimal area of the outlet of the last stage of compression and therefore the pressure actually falls slightly.
At the other end of the burner section are the wide open spaces of the turbine section. There may be a flow guide or stator but the design is such that there is a rapid area increase in the engine which aids in accelerating the gas flow. This also facilitates pressure drop in this section of the engine. There is extra energy in the flow stream from the fuel being burned. The heat energy is translated directly into velocity. The trick of jet engine fuel control is to have a big fire int he engine without making to too big so that the pressure in the burner can gets higher than the outlet of the compressor. If that happens the engine will surge or stall or essentially "fart" out the front, instead of moving air from front to back.
Some of that velocity is given up against the turbines and the extra is thrust at the exhaust nozzle.
At the nozzle outlet there is some design criteria to get a slight pressure rise to aid in the 2+2 formula by varying the area of the outlet.
Now that we are all confused at a higher level, what was the original question?