Breathing And Exchange Of Gases Ques 39
39. Which one of the following is a possibility for most of us in regard to breathing, by making a conscious effort?
[2011M]
(a) One can breathe out air that contains very little or no oxygen.
(b) One can breathe out air through eustachian tubes by closing both the nose and the mouth.
(c) One can consciously breathe in and breathe out by moving the diaphragm alone, without moving the ribs at all.
(d) The lungs cannot be made fully empty by forcefully breathing out all air from them
Show Answer
Answer : b
Hints & Solution
(b) Eustachian tube connects middle ear cavity (tympanic cavity) with nasopharynx. It is approximately $35 mm$ long in adults, which helps equalize pressure by opening during swallowing or yawning.
BETA
