### pressure:

Partial pressure
* Most partial pressure is exerted by gases.
* change as a diver descends and ascends in the water column.
  - simply the pressure exerted by a particular gas in a mixture of gases
* is the pressure exerted by a single gas in the same area in living tissue a
  - way the composition of gases is reported

Pelvic pressure
* keeps pushing diaphragm down.
* results from an increase in size of the uterus or from a particular fibroid.

Radiation pressure
* Most radiation pressure is produced by nuclear reaction
* Some radiation pressure is caused by fusion
  - helium fusion
  - intense fusion
* accelerates the matter to velocities exceeding the escape velocity.
* is pressure
* pushes the material outward while gravity tries to pull it back in.

Root pressure
* is also sometimes visible on leaves.
* is caused by active distribution of mineral nutrient ions into the root xylem
  - transport of mineral nutrient ions into the root xylem
  - often high in some deciduous trees before they leaf out
  - studied by removing the shoot of a plant near the soil level

Selection pressure
* Some selection pressure affects evolution.
* act on characters of organisms which have relevance to survival.
* increases the frequency of plasmids coding for resistance.
* is evident in both wild and captive populations of herbivores.
* leads to accumulation variability
  - character displacement

Selective pressure
* Some selective pressure acts on body size
  - affects primate evolution
* changes aspects.

Social pressure
* are a potent maintainer of family cohesiveness and apparent stability
  - the most counter-productive element facing a person trying to stay healthy
  - usually to blame when horses challenge fences
* is also behind genetic testing.
* is another reason that individuals join the union
  - tool children use on their parents
  - essential for interpersonal coordination

Sound pressure
* accounts for the intensity of the noise when the source is installed in a room.
* is pressure
  - the amount of air pressure fluctuation a noise source creates

Static pressure
* form of potential energy.
* is the normal atmospheric pressure in the absence of sound
* varies as the speed squared.

Suction pressure
* can run in the hundreds or even thousands of pounds.
* concept which applies to a pump.
* is from residual pressure of upstream booster pumps.

Surface pressure
* Some surface pressure acts on faces
  - causes air
* is another condition that affects friction
  - twice that of Earth
* represents pressure reduced to sea level.

Systemic pressure
* fall until more blood is ejected during systole.
* is sensed by receptors in the arteries and atria.

Tire pressure
* Tire Pressure Think about how driving effects the pressure inside the tires.
* affects the ride and gas mileage.
* big concern for cyclists.
* changes with the temperature.
* is an adjustable element of the complete suspension system of the car
  - critical to driving safety
  - important in carrying and gauge wheel drives
  - known to affect the wear-out rate
  - one area that is neglected all too often

Transmural pressure
* induces matrix-degrading activity in porcine arteries ex vivo.
* inhibits prorenin processing in juxtaglomerular cell.

Vapour pressure
* decreases when the temperature is reduced
  - with temperature decrease
* increases when temperatures rise, as surface molecules increase in kinetic energy.
* is an indicator of how easily a chemical evaporates into the air
  - independant of the relative amounts of the two states
* means the tendency of a liquid or solid to volatilise.
* measure of how easily a liquid vaporises, or changes into a gas.

Ventricular pressure
* builds during systole.
* drops below atrial pressure and the mitral valve opens.
* falls rapidly.