Inverse and Direct Proportions - RT Part B

IC

Inspiratory capacity

ERV

Expiratory reserve volume

RV

Residual volume

VC

vital capacity

RV

residual volume

IRV

Inspiratory reserve volume

TV

tidal volume

FRC

functional residual capacity

TLC

total lung capacity

Formula for Charles Law

V1/T1 = V2/T2

• V1 and T1 represent the initial volume and temperature.

• V2 and T2 represent the final volume and temperature.

Normal body temp is

37 celsius

Must convert celsius to kelvin in order to get to charles law

Kevin (Double it) (convert celsius to kevin you will get everything wrong!!!!!

Above 45 = hypoventilation, not clearing (retaining) CO2 effectively, increase ventilation

Below 35 = hyperventilation, blowing off too much CO2, decrease ventilation

Test question: At body temp whats capacity to hold water to

Answer: 44 mg ever liter of ever gas flow (44 is the limit cant go any more)

Boyle’s law is like …. ?

• inverse

•  inverse which means the opposite (ex: one get 2 and the other get 2 so its equal proportion

If you see Formula for Boyle’s Law is P1V1=P2V2 then you know…/

• it is INVERSE

If you see Formula for Gay-Lussac’s Law is P1/T1 = P2/T2 then you know

MUST RMR “Zero degrees celsius is 273 kelvin

Must convert celsius to kelvin in order to get to…?

• charles law

def of Direct Proportions:

Two variables increase or decrease together (e.g., volume and temperature in Charles' Law).

def of Inverse Proportions:

One variable increases while the other decreases (e.g., pressure and volume in Boyle's Law).

Why Charles' Law works

Charles' Law says that volume of gas (like the air you exhale) increases when temperature increases, and decreases when temperature decreases.

The formula V/T = K shows this relationship:

• V = volume

• T = temperature (in Kelvin)

• K = constant (which stays the same if pressure and amount of gas don't change)

Why do we use Kelvin for temperature?

• Temperature in Kelvin is used because it starts at absolute zero (0 K), which is the lowest possible temperature where all movement of particles stops.

• Celsius doesn’t have a "starting point" at absolute zero, which is why we convert Celsius to Kelvin for these calculations.

When you breathe out, the volume of the air depends on the temperature.

• If you're in a cold room (air conditioning), the volume of the air decreases because the temperature is lower.

• If you're in a hot desert, the volume of the air increases because the temperature is higher.

Formula Explanation:

• V1/T1 = V2/T2 helps compare the initial and final volume and temperature:

• V1 = initial volume

• T1 = initial temperature

• V2 = final volume

• T2 = final temperature

Why 273 K?

We add 273 to Celsius to convert it to Kelvin because 0°C is 273 K. This shifts the Celsius scale up to the absolute zero scale.

• For example:

  • 0°C = 273 K

  • 37°C = 310 K (because 273 + 37 = 310)

  • -20°C = 253 K (because 273 - 20 = 253)

Boyle’s Law:

Explains how pressure and volume of a gas are related.

P x V = K:

Pressure (P) and Volume (V) are inversely proportional when temperature is constant.

Inverse relationship

• means when one increases, the other decreases, and vice versa.

Boyle’s Law Formula:

P1V1 = P2V2: This compares the initial and final pressure and volume.

• P1 = initial pressure

• V1 = initial volume

• P2 = final pressure

• V2 = final volume

2T and T₂ are not the same.

• 2T means twice the temperature (just multiply the temperature by 2).

• T₂ refers to the final or second temperature in a comparison or equation (like in gas law equations).

Direct Proportions (Charles' Law) is it not including inverse proportions

Direct Proportion means

means if one value increases, the other increases at the same rate.

• For example, if the temperature doubles, the volume also doubles.

In a Person's Body:

The normal body temperature is about 37°C, which converts to 310 K (because 37°C + 273 = 310 K).

In gas law equations, temperature must be in Kelvin (K), not Celsius (°C). To convert Celsius to Kelvin:

• K = °C + 273

Examples:

• Zero°C = 273 K

• 37°C = 310 K

• -20°C = 253 K

whats Boyle’s Law Formula:

P x V = K
(Pressure and Volume are inversely related, where K is a constant.)

The formula for Boyle’s Law is:

P1V1 = P2V2
(Initial pressure and volume are equal to final pressure and volume.)

• Gas always moves from high pressure to low pressure.

Expiration (breathing out):

• The diaphragm relaxes and moves upward, decreasing the space in the thoracic cage (lungs).

• Less space = less volume = more pressure inside the lungs.

• When pressure inside the lungs is higher than outside, air flows out.

Inspiration (breathing in):

• The diaphragm contracts and moves downward, increasing the space in the thoracic cage (lungs).

• More space = more volume = less pressure inside the lungs.

• When pressure inside the lungs is lower than outside (atmospheric pressure), air flows in.

If the volume is doubled, the temperature must also double to keep the equation balanced.

(2V/2T = K)

FEVt

Forced Expiratory Volume at a specific time (usually 1 second, FEV1)

FVC

Forced Vital Capacity (the total amount of air you can forcefully exhale after a deep breath)

FEVt%

is a percentage that measures how much of the forced vital capacity (FVC) of your lungs is exhaled in a specific amount of time, typically the first second.

ideal normal vt range is?

420-560ml

combined oxygen

hb x 1.34 x So2

To change a decimal to a percent

→ multiply by 100

0.20×100=20%

To change a percent to a decimal

→ divide by 100

25%=0.2525\% = 0.2525%=0.25

O₂ Content

how much oxygen is actually in the blood

O₂ Capacity

the maximum oxygen the blood can carry