Certified Hyperbaric Technologist Test Hyperbaric Physics Fundamentals

Question 1

What does Boyle's Law state and how does it apply to hyperbaric medicine?

Accepted Answer

At constant temperature, gas volume is inversely proportional to pressure — explains barotrauma and why air spaces compress under pressure

Answer

Boyle's Law (PV=k) states that gas volume decreases proportionally as pressure increases at constant temperature, explaining why middle ear spaces, sinuses, and lungs compress during descent and expand during ascent.

Question 2

What does Henry's Law state and why is it important in HBO therapy?

Accepted Answer

Gas dissolved in a liquid is proportional to the partial pressure of that gas — explains how HBO increases dissolved oxygen in blood

Answer

Henry's Law states that the amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid, explaining how breathing oxygen at elevated pressures dramatically increases dissolved oxygen in plasma.

Question 3

What is Dalton's Law of Partial Pressures?

Accepted Answer

The total pressure of a gas mixture equals the sum of the partial pressures of each component gas

Answer

Dalton's Law states that each gas in a mixture exerts pressure independently, and the total pressure equals the sum of all partial pressures. At 3 ATA breathing 100% O2, the PO2 is 3.0 ATA × 1.0 = 3.0 ATA (2,280 mmHg).

Question 4

What is oxygen toxicity and what are its two forms?

Accepted Answer

Harmful effects from excessive oxygen: CNS toxicity (seizures) at high pressures and pulmonary toxicity from prolonged exposure

Answer

CNS oxygen toxicity (Paul Bert effect) occurs at high partial pressures (typically >2.0 ATA PO2) causing seizures, while pulmonary toxicity (Lorrain Smith effect) results from prolonged breathing of elevated oxygen, causing lung inflammation.

Question 5

How does gauge pressure differ from absolute pressure in hyperbaric medicine?

Accepted Answer

Gauge measures pressure above atmospheric; absolute includes atmospheric pressure (gauge + 1 ATA at sea level)

Answer

Gauge pressure (psig) measures pressure above atmospheric baseline, while absolute pressure (psia or ATA) includes atmospheric pressure. At sea level: 1 ATA absolute = 0 psig. At 2 ATA: gauge is 14.7 psig.

Certified Hyperbaric Technologist Test Practice Test

Certified Hyperbaric Technologist Test Practice Test

Certified Hyperbaric Technologist Test Hyperbaric Physics Fundamentals