The maximum force the muscles of the diaphragm can exert is 24,000 N. What maximum pressure difference can the diaphragm withstand? 

(a) 160 mm Hg;

(b) 760 mm Hg;

(c) 920 mm Hg;

(d) 5000 mm Hg.

An elephant can swim or walk with its chest several meters underwater while the animal breathes through its trunk, which remains above the water surface and acts like a snorkel. The elephant??s tissues are at an increased pressure due to the surrounding water, but the lungs are at atmospheric pressure because they are connected to the air through the trunk. The figure shows the gauge pressures in an elephant??s lungs and abdomen when the elephant??s chest is submerged to a particular depth in a lake. In this situation, the elephant??s diaphragm, which separates the lungs from the abdomen, must sustain the difference in pressure between the lungs and the abdomen. The diaphragm of an elephant is typically 3.0 cm thick and 120 cm in diameter.

Transcribed Image Text:

Water surface Lungs: O mm Hg - Diaphragm Abdomen: 150 mm Hg