Ralph is taking scuba diving classes and is warned not to hold ...

[hbsimmons88]

Ralph is taking scuba diving classes and is warned not to hold his breath when ascending from depth but to continuously release air from his mouth. What is the basis of this instruction and what is the risk if it is ignored?

Question 2

A period of adjustment is required when moving from a dark room into bright light because
 A) the breakdown of rhodopsin to opsin occurs slowly.
  B) the lens requires time to accommodate dim light.
  C) rods exposed to strong light need time to regenerate rhodopsin.
  D) rhodopsin does not function in dim light.
  E) only cones function in dim light.

[14vl19]

Answer to Question 1

When breathing underwater with scuba equipment, gas is supplied by the tank at higher than atmospheric pressure to overcome the extra pressure imposed by the overlying water. According to Boyle's Law, during ascent when the pressure falls, the volume of gas contained in the lungs will expand. If not permitted to escape through the mouth, nitrogen will come out of solution and form gas bubbles in the joint as well as in the blood stream. A massive air embolism in the pulmonary arteries could be suddenly fatal.

Answer to Question 2

C

[hbsimmons88]

TYSM

[Joy Chen]

Excellent