WCU PHYS 261 FINAL EXAM 2025/2026
QUESTIONS AND ANSWERS 100% PASS
Internal respiration and external respiration - ANS What are the 2 types of respiration?
from a high area to a low area - ANS In which direction does air flow due to pressure
differences?
Gas exchange that occurs between the aleveoli and RBCs, and between the RBCs and tissue -
ANS What is internal respiration?
air movement between the lungs and the atmosphere - ANS What is external respiration?
when air moves from the atmosphere into the lungs - ANS What is inhalation?
when air moves from the lungs into the atmosphere - ANS What is exhalation?
that pressure and volume are inversely proportional - ANS What is Boyle's Law?
760 mmHg - ANS What is the atmospheric pressure at sea level?
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,pressure inside the lungs - ANS What is intrapulmonary pressure?
volume inside the lungs - ANS What is intrapulmonary volume?
760mmHg - ANS What is the atmospheric pressure and intrapulmonary pressure when you
are at rest?(neither inhaling or exhaling)
400ml air - ANS What is the lung volume during rest?
lower - ANS For inspiration, is the intrapulmonary pressure higher or lower than the
atmospheric pressure?
-blood O2 levels are low, while CO2 is high
-chemoreceptors get stimulated
-chemoreceptors stimulate medulla(respiratory center)
-medulla stimulates the phrenic nerve
-phrenic nerve stimulates the diaphragm and respiratory muscles
-diaphragm and muscles move down and outward
-negative pressure created inside the lungs
-thoracic veins drain blood into the lungs
-increase in intrapulmonary volume
-decrease in intrapulmonary pressure by 4mmHg= 756mmHg
-air enters lungs - ANS What are the steps of inspiration?
Central receptors
-located near the medulla
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, -detect hydrogen concentration in CSF and by detecting hydrogen, it can tell if CO2 has
increased
Peripheral receptors
-found in carotid artery and aortic bodies
-detects a decrease in O2 levels, and if decreased, it stimulates the medulla - ANS What are
the 2 types of chemoreceptors and their functions?
-inhalation caused the lungs to be filled with air
-stimulates stretch receptors within the medulla
-medulla inhibits the phrenic nerve
-diaphragm and respiratory muscles no longer stimulated by phrenic nerve
-diaphragm and muscles relax
-diaphragm moves up and muscles move inward
-lungs recoil properly
-blood is pushed out of the lungs
-decrease in intrapulmonary volume
-increase in intrapulmonary pressure by 8mmHg= 764mmHg
-air leaves lungs - ANS What are the steps of expiration?
a- tidal volume(TV): a normal breath
b- inspiratory reserve volume(IRV): the amount of air your can forcefully inhale after a normal
inhale
c- expiratory reserve volume(ERV): the amount of air you can forcefully exhale after a normal
exhale
d- vital capacity(VC): the amount of air that can be manipulated
e- residual volume(RV): the amount of air always left in the lungs
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
QUESTIONS AND ANSWERS 100% PASS
Internal respiration and external respiration - ANS What are the 2 types of respiration?
from a high area to a low area - ANS In which direction does air flow due to pressure
differences?
Gas exchange that occurs between the aleveoli and RBCs, and between the RBCs and tissue -
ANS What is internal respiration?
air movement between the lungs and the atmosphere - ANS What is external respiration?
when air moves from the atmosphere into the lungs - ANS What is inhalation?
when air moves from the lungs into the atmosphere - ANS What is exhalation?
that pressure and volume are inversely proportional - ANS What is Boyle's Law?
760 mmHg - ANS What is the atmospheric pressure at sea level?
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,pressure inside the lungs - ANS What is intrapulmonary pressure?
volume inside the lungs - ANS What is intrapulmonary volume?
760mmHg - ANS What is the atmospheric pressure and intrapulmonary pressure when you
are at rest?(neither inhaling or exhaling)
400ml air - ANS What is the lung volume during rest?
lower - ANS For inspiration, is the intrapulmonary pressure higher or lower than the
atmospheric pressure?
-blood O2 levels are low, while CO2 is high
-chemoreceptors get stimulated
-chemoreceptors stimulate medulla(respiratory center)
-medulla stimulates the phrenic nerve
-phrenic nerve stimulates the diaphragm and respiratory muscles
-diaphragm and muscles move down and outward
-negative pressure created inside the lungs
-thoracic veins drain blood into the lungs
-increase in intrapulmonary volume
-decrease in intrapulmonary pressure by 4mmHg= 756mmHg
-air enters lungs - ANS What are the steps of inspiration?
Central receptors
-located near the medulla
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, -detect hydrogen concentration in CSF and by detecting hydrogen, it can tell if CO2 has
increased
Peripheral receptors
-found in carotid artery and aortic bodies
-detects a decrease in O2 levels, and if decreased, it stimulates the medulla - ANS What are
the 2 types of chemoreceptors and their functions?
-inhalation caused the lungs to be filled with air
-stimulates stretch receptors within the medulla
-medulla inhibits the phrenic nerve
-diaphragm and respiratory muscles no longer stimulated by phrenic nerve
-diaphragm and muscles relax
-diaphragm moves up and muscles move inward
-lungs recoil properly
-blood is pushed out of the lungs
-decrease in intrapulmonary volume
-increase in intrapulmonary pressure by 8mmHg= 764mmHg
-air leaves lungs - ANS What are the steps of expiration?
a- tidal volume(TV): a normal breath
b- inspiratory reserve volume(IRV): the amount of air your can forcefully inhale after a normal
inhale
c- expiratory reserve volume(ERV): the amount of air you can forcefully exhale after a normal
exhale
d- vital capacity(VC): the amount of air that can be manipulated
e- residual volume(RV): the amount of air always left in the lungs
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
