Answer to Question 1
ANS: C
An increase in dead space ventilation, or VD/VT, is caused by either (1) a decreased tidal volume as with rapid, shallow breathing (an increase in anatomic dead space per minute) or (2) increased physiologic dead space as in pulmonary embolus. (= 0). In either case, the proportion of wasted ventilation increases.
Answer to Question 2
ANS: B
Methemoglobin (metHb) is an abnormal form of the molecule, in which the heme-complex nor-mal ferrous iron ion (Fe2+) loses an electron and is oxidized to its ferric state (Fe2+). In the ferric state, the iron ion cannot combine with O2. The result is a special form of anemia called methe-moglobinemia. As with HbCO, clinical abnormalities come from the associated increased affinity for O2 and loss of oxygen-binding capacity. The most common cause of methemoglobinemia is the therapeutic use of oxidant medications such as nitric oxide, nitroglycerin, and lidocaine. When using these therapeutic agents, frequent monitoring for metHg is important to weigh the risk against the benefit.
Ventilation of the mammalian lung by negative pressure filling.
Much of the dark space between stars, as seen in the sky of the image above, is due to the human eye
Diaphragm, the major muscle of breathing.
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A 31.1-g sample of Ne gas exerts a certain pressure in a container of fixed volume. What mass ...