Transport of Oxygen and Carbon Dioxide in Blood and Tissue Fluids
50 questions available
Questions
Where are the aortic bodies, which are peripheral chemoreceptors, primarily located?
View answer and explanationWhat is the rate of blood flow through the chemoreceptor bodies, such as the carotid and aortic bodies?
View answer and explanationDue to the extreme blood flow they receive, what type of blood are the peripheral chemoreceptors constantly exposed to?
View answer and explanationIn which range of arterial Po2 is the impulse rate from a carotid body particularly sensitive to changes?
View answer and explanationWhat are the glandular-like cells within the carotid and aortic bodies that function as chemoreceptors and stimulate afferent nerve endings?
View answer and explanationWhat is the initial event in glomus cells that leads to their stimulation when blood Po2 decreases markedly?
View answer and explanationFollowing depolarization of a glomus cell due to low Po2, what specific ion influx increases the intracellular concentration and stimulates neurotransmitter release?
View answer and explanationWhile early studies suggested dopamine or acetylcholine, what do more recent studies suggest is the key excitatory neurotransmitter released by carotid body glomus cells during hypoxia?
View answer and explanationHow does the power of the direct effects of increased CO2 and H+ concentration in the respiratory center compare to their indirect effects mediated through peripheral chemoreceptors?
View answer and explanationWhat is the key difference in the speed of response between peripheral chemoreceptor stimulation and central stimulation by CO2?
View answer and explanationAs long as the arterial Po2 remains greater than 100 mm Hg, and Pco2 and H+ concentrations are kept normal, what is the effect on alveolar ventilation?
View answer and explanationWhen arterial Po2 falls to 60 mm Hg while Pco2 and H+ levels are held constant, by how much does alveolar ventilation approximately increase?
View answer and explanationWhat is the term for the phenomenon where mountain climbers, after ascending slowly over days, breathe much more deeply and can withstand lower atmospheric O2 concentrations?
View answer and explanationWhat is the primary reason for acclimatization, which allows for a greater respiratory response to low O2 after 2 to 3 days?
View answer and explanationDue to acclimatization over 2 to 3 days, by how much can alveolar ventilation increase in response to low O2, compared to the initial acute increase?
View answer and explanationWhat do the four red curves in the composite diagram of Figure 42-8 represent?
View answer and explanationIn the composite diagram shown in Figure 42-8, the green curves were measured at a blood pH of 7.3. How do they compare to the red curves measured at a pH of 7.4?
View answer and explanationDuring strenuous exercise, by how much can oxygen consumption and carbon dioxide formation increase in a healthy athlete?
View answer and explanationIn a healthy athlete undergoing strenuous exercise, what typically happens to the arterial Po2, Pco2, and pH?
View answer and explanationGiven that arterial blood gas and pH values do not change significantly during exercise, what is believed to be the predominant cause of the intense increase in ventilation?
View answer and explanationAccording to the description of Figure 42-10, what happens to alveolar ventilation at the immediate onset of exercise?
View answer and explanationWhat is the initial effect on arterial Pco2 when ventilation increases at the start of exercise?
View answer and explanationAfter the initial changes at the onset of exercise, approximately how long does it take for the amount of CO2 released from the muscles to match the increased ventilation rate, causing arterial Pco2 to return to normal?
View answer and explanationAs summarized in Figure 42-11, what is the approximate upward shift in the Pco2-ventilation response curve caused by the neurogenic factor during heavy exercise?
View answer and explanationWhat evidence suggests that the neurogenic control of ventilation during exercise may be partly a learned response involving the cerebral cortex?
View answer and explanationWhat is the primary function of the pulmonary irritant receptors located in the epithelium of the trachea, bronchi, and bronchioles?
View answer and explanationWhere are Lung J receptors located, and what sensation might their excitation cause?
View answer and explanationWhat is the primary effect of acute brain edema, such as that resulting from a brain concussion, on the respiratory center?
View answer and explanationWhat does the text identify as perhaps the most prevalent cause of respiratory depression and respiratory arrest?
View answer and explanationCheyne-Stokes breathing is a type of periodic breathing characterized by a slowly waxing and waning respiration that repeats itself over what time interval?
View answer and explanationWhat is the basic underlying cause of the cyclical pattern in Cheyne-Stokes breathing?
View answer and explanationWhy does Cheyne-Stokes breathing not typically occur in healthy individuals despite the underlying mechanism being present in everyone?
View answer and explanationIn which clinical condition is Cheyne-Stokes breathing often seen due to a prolonged delay in blood transport from the lungs to the brain?
View answer and explanationWhat is the second cause of Cheyne-Stokes breathing, which involves an increased negative feedback gain in the respiratory control areas?
View answer and explanationDuring Cheyne-Stokes breathing, the depth of respiration corresponds with the Pco2 level in which location?
View answer and explanationWhat is the medical term for the absence of spontaneous breathing?
View answer and explanationIn individuals with sleep apnea, what is the typical duration and frequency of the apneic episodes?
View answer and explanationWhat is the underlying cause of obstructive sleep apnea?
View answer and explanationWhat are the physiological consequences that result from the periods of apnea in a person with sleep apnea?
View answer and explanationWhat is the name of the surgical procedure used to treat obstructive sleep apnea by removing excess fat tissue from the back of the throat?
View answer and explanationWhat is the primary cause of 'central' sleep apnea?
View answer and explanationWhat is the estimated percentage of all sleep apnea cases that are accounted for by the 'mixed' type, a combination of obstructive and central mechanisms?
View answer and explanationWhat does the text identify as the most common cause of sleep apnea?
View answer and explanationWhat does the section on 'Voluntary Control of Respiration' state about the ability of a person to control their breathing?
View answer and explanationWhat is the reported world record for voluntary breath-holding (apnea) under static resting conditions without pre-hyperventilating with pure oxygen?
View answer and explanationAfter hyperventilating with pure oxygen and expelling large amounts of CO2, for how long have individuals been able to hold their breath underwater?
View answer and explanationTo what level can oxygen saturation fall in ultra-elite apnea competitors before unconsciousness limits the breath-hold duration?
View answer and explanationBased on the diagram of carotid body glomus cell oxygen sensing (Figure 42-6), what is the direct cause of cell depolarization when PO2 levels fall?
View answer and explanationAccording to the composite diagram showing the effects of Pco2, Po2, and pH on alveolar ventilation (Figure 42-8), what is the effect of decreasing pH from 7.4 to 7.3?
View answer and explanationBased on Figure 42-10, what is the immediate response of alveolar ventilation when a 1-minute period of exercise is terminated?
View answer and explanation