Respiratory System - MCB 246 Questions With Complete
Solutions
Abdominal muscles (external oblique, transversus abdominis)
Correct Answers Compress the abdomen & force diaphragm
upward
alveolar ventilation Correct Answers • Amount of air reaching
alveoli each minute
• On average, VA = 12 x (500 ml - 150 ml) = 4.2 liters of
air/min
• However, realize that the gas reaching the alveoli has mixed
with exhaled air in the anatomical dead space, so contains less
O2 and more CO2 than surrounding atmospheric air.
alveolar ventilation formula Correct Answers VA = ƒ x (VT -
VD)
articulation Correct Answers Modification of sound by other
structures - tongue, lips, teeth, cheeks plus resonance and
amplification by the pharynx, oral and nasal cavities, and
sinuses
average (eupnea) VE Correct Answers 12 x 500 ml = 6 liters of
air/min
Blood flow in the alveolar capillaries is coordinated with
alveolus PO2 : alveoli with the highest PO2 receive ... Correct
Answers the highest amount of blood flow (maximal
vasodilation) ensuring maximal O2 exchange
, Boyle's Law (P=1/V) Correct Answers Pressure of a gas in a
closed container at constant temperature is inversely
proportional to the volume
Cells produce energy for ... Correct Answers maintenance,
growth, defense, and division through mechanisms that use O2
and produce CO2
CO2 Exchange in the Lungs Correct Answers 1. Dissolved CO2
diffuses from plasma into alveoli air space due to large PCO2
difference
2. On-loading of O2 to Hb (Not shown) causes H+s to be
released in the RBCs, thereby facilitating the formation of CO2
first from RBC HCO3 - and then from HCO3 - taken up by
RBCs from the plasma
3. Lung carbonic anhydrase also helps convert some plasma
HCO3 - into CO2
CO2 Transport in Bloodstream from peripheral tissues to lungs:
Correct Answers 1. 70% is converted into carbonic acid
(H2CO3)
• dissociates into a H+ & bicarbonate (HCO3⁻)
RBC HCO3⁻ exchanged for plasma Cl⁻ in a process known as
the chloride shift, and the H⁺ is buffered in the RBC (primarily
by Hb)
2. 23% is bound to amino groups of Hb forming
carbaminohemoglobin
Solutions
Abdominal muscles (external oblique, transversus abdominis)
Correct Answers Compress the abdomen & force diaphragm
upward
alveolar ventilation Correct Answers • Amount of air reaching
alveoli each minute
• On average, VA = 12 x (500 ml - 150 ml) = 4.2 liters of
air/min
• However, realize that the gas reaching the alveoli has mixed
with exhaled air in the anatomical dead space, so contains less
O2 and more CO2 than surrounding atmospheric air.
alveolar ventilation formula Correct Answers VA = ƒ x (VT -
VD)
articulation Correct Answers Modification of sound by other
structures - tongue, lips, teeth, cheeks plus resonance and
amplification by the pharynx, oral and nasal cavities, and
sinuses
average (eupnea) VE Correct Answers 12 x 500 ml = 6 liters of
air/min
Blood flow in the alveolar capillaries is coordinated with
alveolus PO2 : alveoli with the highest PO2 receive ... Correct
Answers the highest amount of blood flow (maximal
vasodilation) ensuring maximal O2 exchange
, Boyle's Law (P=1/V) Correct Answers Pressure of a gas in a
closed container at constant temperature is inversely
proportional to the volume
Cells produce energy for ... Correct Answers maintenance,
growth, defense, and division through mechanisms that use O2
and produce CO2
CO2 Exchange in the Lungs Correct Answers 1. Dissolved CO2
diffuses from plasma into alveoli air space due to large PCO2
difference
2. On-loading of O2 to Hb (Not shown) causes H+s to be
released in the RBCs, thereby facilitating the formation of CO2
first from RBC HCO3 - and then from HCO3 - taken up by
RBCs from the plasma
3. Lung carbonic anhydrase also helps convert some plasma
HCO3 - into CO2
CO2 Transport in Bloodstream from peripheral tissues to lungs:
Correct Answers 1. 70% is converted into carbonic acid
(H2CO3)
• dissociates into a H+ & bicarbonate (HCO3⁻)
RBC HCO3⁻ exchanged for plasma Cl⁻ in a process known as
the chloride shift, and the H⁺ is buffered in the RBC (primarily
by Hb)
2. 23% is bound to amino groups of Hb forming
carbaminohemoglobin
