How does the behavior of fluids in different states compare?

Poiseuille’s lawflow = (P1 - P2) r4

--------------------

8vl

Flow= P1-P2/R

Properties of liquids… Properties of gases…

Boyles: P1V1=P2V2

Charles: P1V1/T1 = P2V2/T2

Combined:P = nRT/V

Take a deep breath and try to determine:

Which muscles are involved?

and

Are they relaxing or contracting?

How do we ventilate?

To force air out, what has to happen to volume?

Accomplished by:• relaxation

during quiet breathing

• contraction during forced breathing...

1) internal intercostals

2) abdominal muscles

How do we ventilate (expiration)?

Air flows due to differences in pressure

Pressure: P1V1 = P2V2

So…increased volume = ?

Accomplished with:

1) external intercostal muscles

2) diaphragm 3) additional ones when needed

How do we ventilate (inspiration)?

Take 5!!!

Discuss with your neighbor and predict

an answer

With the heart, we can directly alter the pressure of the fluid by applying force to the fluid resulting in a change in pressure and volume. However, with the lungs, there is no way to directly influence the fluid pressure (air) at the point of origin. So, how do we pump air into our lungs?

BI 203 Human Anatomy & Physiology IIBI 203 Human Anatomy & Physiology II

How does SCUBA affect the respiratory system?

How does the gear work?

BIOL2030 Human Anatomy & Physiology IIBIOL2030 Human Anatomy & Physiology II

BI 203 Human Anatomy & Physiology IIBI 203 Human Anatomy & Physiology II

How does SCUBA affect the respiratory system?

What were the rules (1-3?) discussed by the dive instructor yesterday?

How does SCUBA affect the respiratory system?A key aspect to consider is the compressibility of gases vs. the incompressibility of liquids.

Where in your body do you have air spaces?

Those areas can be directly affected by changes in pressure/volume.

33 feet of water = the pressure from 1 atmosphere

Pressure?

Pressure?

Pressure?

33’

66’

99’

How does SCUBA affect the respiratory system?

33’

66’

99’

33’

66’

99’

33’

66’

99’

Effects on volume Effects on density Effects of equalized pressure

How does SCUBA affect the respiratory system?

Pressure?

Pressure?

Pressure?

33’

66’

99’

When snorkeling, what happens to pressure and volume in respiratory system?

How does SCUBA affect the respiratory system?

Pressure?

Pressure?

Pressure?

33’

66’

99’

When SCUBA diving and breathing at depth, then holding your breath while ascending, what happens to pressure and volume in respiratory system?

Abyss clip

Are there other air spaces to consider when diving?

Henry’s Law:Concentration of a gas in a liquid depends on the the Partial pressure of the gas and the solubility of that particular gas.

[O2] = PO2 * Solubility

Does anything else change with pressure?

33’

66’

99’What is PN2?

(760)(4)(.79) = 2402

What is PN2?

(760)(1)(.79) = 600

Coefficient for O2 in water is 0.024

CO2 in water is 0.57

Take 5!!!

Discuss with your neighbor and predict

an answer

What is the effect on a person’s blood N2 levels, when diving at depths that are too deep (high pressure) for too long of a time?

How does SCUBA affect the respiratory system?

Other anatomy & physiology concerns…

Breathing compressed O2

Breathing compressed air while snorkeling

Holding your breath longer while snorkeling

Nitrogen narcosis

Vertigo

Not following the rules