Pressure and Gases

Question 1

Pressure

Answer 1

Pressure is physical force exerted on or against an object by something in contact with it. Pressure= Force/Area. Measured in pascals

Question 2

Pressure within healthcare

Answer 2

mmHg: millimeters (mm) of mercury (HG)
- measuring BP/ inspiratory and expiratory pressure.

CMH20- centimeters of water: used in the measurement of central venous pressure

PSI: pounds per square inch: pressure compressed gases and direct pressure on a object

Question 3

State pressure and liquid application

Answer 3

IV fluids: the higher the fluid container (IV bag) the faster the outward flow of the fluid to the patient.
-Syringe use: pressure is higher from smaller syringes-important when administering intravenous drugs.

Question 4

Describe Blood flow and pressure

Answer 4

BP constriction of vessels decreases flow and increases BP.
-Dilated vessels can increase glow and decrease BP
Pumping efficiency of the heart can also effect blood pressure

Question 5

Define gas laws

Answer 5

Related to kinetic theory. Matter is composed of tiny particles in constant motion
- low density/ has no definite shape of volume/ gas fills any container it occupies/ easy to compress

Question 6

Boyles Law

Answer 6

As volume occupied increase pressure decrease
as volume occupied decreases pressure increases
- syringe usage/ exhaling and inhaling

Question 7

Daltons Law

Answer 7

Total pressure exerted is equal to the sum of the partial pressures of the individual gases

• Partial pressure of a gas in a mixture is the pressure that gas would exert if it occupied the total volume of the mixture.
• Sum of all partial pressures of gas in a mixture should equal the barometic pressure.

Question 8

Dalton law in clinical application

Answer 8

Diving bends- presure effecting the concentration of gases at depth. Decompression required to equalize the pressure within the body.

Question 9

Henrys law

Answer 9

Mass of gas that will dissolve in water at a given temperature is proportional to the partial pressure of the gas and its solubility coefficient.

Question 10

Henrys Law basic examples

Answer 10

Gas exchange
Alveolar air
Concentration gradients
- saturation level: the amount of Haeme that is attached to oxygen.

Question 11

Henrys law clinical application

Answer 11

Saturation levels- amount of Haemoglobin molecules with O2 attached -indication of respriatory function and potential anaemia
-Oxygen therapy-we can inhale concentrated oxygen and change the alveolar air composition thus increasing the oxygen partial pressure.
Nebulizers: pressurized gas create a Bernoulli effect inside a mask to administer fluids in droplet form

Question 12

what are some of the pressure measurements in healthcare

Answer 12

MMHg- milimeters of mercury
cmH20- centimeters of water
PSi- pounds per sqaure inch

Question 13

Describe MMHG

Answer 13

used in BP and to measure inspiratory and expiratory pressure

Question 14

CMh20

Answer 14

Centimeters of water:

Used to measure central venous fluid

Question 15

PSI

Answer 15

Pounds per square inch- compressed gases and direct pressure on a object

Question 16

What is bernoullis law

Answer 16

as fluid increases speed the pressure within the fluid descreases. F ^/ P within the F decreases