BPK 105 FINAL EXAM QUESTIONS WITH VERIFIED
ACCURATE ANSWERS
Describe the functions of the respiratory system - Answers - Main function: Respiration
which includes the movement of air into and out of the lungs, exchange of CO2 and O2,
transport of CO2 and O2 in the blood and exchange O2 and CO2 in tissues
Regulation of blood pH by changing CO2 levels
Voice production through air passing the vocal cords
Olfaction from drawing airborne molecules into the nasal cavity
Innate immunity by removing pathogens from respiratory surfaces
Describe the pressure changes involved during inspiration and expiration include the
changes in thoracic volume and specific muscle contractions during one breathing cycle
at rest and during exercise - Answers - During inspiration, alveolar pressure drops
below atmospheric pressure due to the contraction of diaphragm inferiorly and
intercostals pushing the ribcage upwards causing thoracic volume to increase.
During expiration alveolar pressure is higher than atmospheric pressure and intercostals
and diaphragm relax to reduce the thoracic volume and let air be expired.
During labored breathing the thoracic cavity volume increases greatly and all the
inspiratory muscles are active and they contract more forcefully. These muscles include
abdominals and intercostals.
Describe surfactant and pleural pressure including their roles of in preventing the
collapse of alveoli. Briefly describe infant respiratory disease syndrome (IRDS) in
premature infants and why it is critical to treat it effectively. - Answers - Surfactant is a
lipoprotein mixture that prevents alveoli from recoiling with enough force to cause
collapse by reducing surface tension.
Pleural pressure is less than alveolar pressure causing the alveoli to expand, this is
caused by a suction effect from the lymphatic system removing fluid and lung recoil.
IRDS is caused by too little surfactant in a premature infant. This is important to treat to
prevent lung collapse so an expecting mother may be given cortisol which increases
surfactant synthesis in the fetus.
Describe gas exchange in the pulmonary and systemic circulatory systems for oxygen
and carbon dioxide. Include the changes in partial pressures for both of these dissolved
, gases and the driving force for exchange at each location. What impact would
pulmonary edema, an increase in interstitial fluid in the lungs, have on gas exchange?
List the other factors could influence the rate of gas exchange at the respiratory
membrane? - Answers - O2 diffuses through the respiratory membranes 20 times less
easily than does CO2
Oxygen diffuses from the alveoli into the pulmonary capillaries because the Po2 in the
alveoli is greater than the capillaries.
CO2 diffuses from the pulmonary capillaries into the alveoli because Pco2 is greater in
the capillaries than in the alveoli
Edema causes there to be a thicker than normal layer of fluid for the gases to diffuse
across. This causes the rate of gas exchange to markedly decrease, this affects oxygen
before CO2 due to their differences in diffusion.
Describe the transport of oxygen in circulation. What environmental changes occur as
blood enters active muscle influence the release of oxygen from hemoglobin? How does
the release of oxygen differ during exercise? - Answers - 98.5% of oxygen is carried in
the blood through the heme group of oxyhemoglobin. At high Po2 hemoglobin binds to
O2 and at low Po2 it releases O2. This causes O2 to be released into the tissues.
The amount of O2 released from oxyhemoglobin depends on low Po2, high Pco2, low
pH and high temperature.
When exercising the Po2 is lower and Pco2 is higher as well as low pH and high
temperature this causes as much as 73% of the O2 picked up in the lungs by
hemoglobin to be released into tissues
Describe the various ways carbon dioxide is transported in circulation, including the
approximate percentage that is transported in each way include the full reaction
catalyzed by carbonic anhydrase. How does this equilibrium reaction change between
the tissues and the lungs - Answers - Carbon dioxide is transported through the blood
through dissolved CO2 in the plasma, bound to blood proteins and in the form of
bicarbonate ions.
Approximately 7% is transported through the plasma, 23% in blood proteins and 70% in
bicarbonate ions.
The enzyme carbonic anhydrase within RBC's helps to catalyze the reaction in which
bicarbonate ions are formed. Carbonic anhydrase speeds up the reaction producing
bicarbonate ions by increasing the reactivity between CO2 and water.
When the reaction is in the region of the lungs, the reaction becomes reversed and
HCO3 combines with H+ leading to the expiration of CO2.
ACCURATE ANSWERS
Describe the functions of the respiratory system - Answers - Main function: Respiration
which includes the movement of air into and out of the lungs, exchange of CO2 and O2,
transport of CO2 and O2 in the blood and exchange O2 and CO2 in tissues
Regulation of blood pH by changing CO2 levels
Voice production through air passing the vocal cords
Olfaction from drawing airborne molecules into the nasal cavity
Innate immunity by removing pathogens from respiratory surfaces
Describe the pressure changes involved during inspiration and expiration include the
changes in thoracic volume and specific muscle contractions during one breathing cycle
at rest and during exercise - Answers - During inspiration, alveolar pressure drops
below atmospheric pressure due to the contraction of diaphragm inferiorly and
intercostals pushing the ribcage upwards causing thoracic volume to increase.
During expiration alveolar pressure is higher than atmospheric pressure and intercostals
and diaphragm relax to reduce the thoracic volume and let air be expired.
During labored breathing the thoracic cavity volume increases greatly and all the
inspiratory muscles are active and they contract more forcefully. These muscles include
abdominals and intercostals.
Describe surfactant and pleural pressure including their roles of in preventing the
collapse of alveoli. Briefly describe infant respiratory disease syndrome (IRDS) in
premature infants and why it is critical to treat it effectively. - Answers - Surfactant is a
lipoprotein mixture that prevents alveoli from recoiling with enough force to cause
collapse by reducing surface tension.
Pleural pressure is less than alveolar pressure causing the alveoli to expand, this is
caused by a suction effect from the lymphatic system removing fluid and lung recoil.
IRDS is caused by too little surfactant in a premature infant. This is important to treat to
prevent lung collapse so an expecting mother may be given cortisol which increases
surfactant synthesis in the fetus.
Describe gas exchange in the pulmonary and systemic circulatory systems for oxygen
and carbon dioxide. Include the changes in partial pressures for both of these dissolved
, gases and the driving force for exchange at each location. What impact would
pulmonary edema, an increase in interstitial fluid in the lungs, have on gas exchange?
List the other factors could influence the rate of gas exchange at the respiratory
membrane? - Answers - O2 diffuses through the respiratory membranes 20 times less
easily than does CO2
Oxygen diffuses from the alveoli into the pulmonary capillaries because the Po2 in the
alveoli is greater than the capillaries.
CO2 diffuses from the pulmonary capillaries into the alveoli because Pco2 is greater in
the capillaries than in the alveoli
Edema causes there to be a thicker than normal layer of fluid for the gases to diffuse
across. This causes the rate of gas exchange to markedly decrease, this affects oxygen
before CO2 due to their differences in diffusion.
Describe the transport of oxygen in circulation. What environmental changes occur as
blood enters active muscle influence the release of oxygen from hemoglobin? How does
the release of oxygen differ during exercise? - Answers - 98.5% of oxygen is carried in
the blood through the heme group of oxyhemoglobin. At high Po2 hemoglobin binds to
O2 and at low Po2 it releases O2. This causes O2 to be released into the tissues.
The amount of O2 released from oxyhemoglobin depends on low Po2, high Pco2, low
pH and high temperature.
When exercising the Po2 is lower and Pco2 is higher as well as low pH and high
temperature this causes as much as 73% of the O2 picked up in the lungs by
hemoglobin to be released into tissues
Describe the various ways carbon dioxide is transported in circulation, including the
approximate percentage that is transported in each way include the full reaction
catalyzed by carbonic anhydrase. How does this equilibrium reaction change between
the tissues and the lungs - Answers - Carbon dioxide is transported through the blood
through dissolved CO2 in the plasma, bound to blood proteins and in the form of
bicarbonate ions.
Approximately 7% is transported through the plasma, 23% in blood proteins and 70% in
bicarbonate ions.
The enzyme carbonic anhydrase within RBC's helps to catalyze the reaction in which
bicarbonate ions are formed. Carbonic anhydrase speeds up the reaction producing
bicarbonate ions by increasing the reactivity between CO2 and water.
When the reaction is in the region of the lungs, the reaction becomes reversed and
HCO3 combines with H+ leading to the expiration of CO2.
