Term
| What is the difference between static conditions and dynamic conditions? |
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Definition
| Static is a “snapshot in time” where there is no airflow in the system and changes in volume do not occur, whereas in dynamic air flow and volume changes occur and the forces in the system are not in equilibrium |
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Term
| With respect to atmospheric pressure, pleural pressure is __________? |
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Definition
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Term
| The resultant lung volume that refers to when the recoil forces of the lung and chest wall are in equilibrium is called what? |
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Definition
| Functional residual capacity FRC |
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Term
| What happens to functional residual capacity when lung recoil is increased or decreased by disease? |
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Definition
| Increased - the FRC decreases, Decreased - the FRC increases |
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Term
| How do you determine the lung recoil pressure, known as transpulmonary pressure? |
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Definition
| Alveolar pressure - intrapleural pressure |
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Term
| What two factors account for the recoil force of the lung? |
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Definition
| Elastic tissue and surface forces |
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Term
| True or False: lung compliance is defined as the change in volume of the lung produced per unit of transpulmonary pressure. |
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Definition
| True, C= (change in V)/(Palv-Ppl) |
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Term
| Which of these 3 are advantages of pulmonary surfactants - increased lung compliance, reduced surface tension, countering tendency for smaller alveoli to empty to larger ones, prevention of transudation of fluid into alveoli from capillaries? |
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Definition
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Term
| Is expiratory air flow low or high when the following occur - low Ppl, low Pst, high airway resistance? |
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Definition
| When each of those occur airflow is low |
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Term
| True or False: When you tell a patient to perform a forced expiratory maneuver in order to make pleural pressure positive this guarantees increased expiratory flow. |
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Definition
| False, not necessarily because the equal pressure point tends to be fixed and is major factor in determining forced expiratory flow |
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Term
| What is the primary determinant of expiratory flow in normal breathing? |
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Definition
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Term
| What is the EPP, equal pressure point? |
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Definition
| The point where the change in luminal pressure is equal to the Pst(L), where the intra-luminal pressure equals the extra-mural pressure |
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Term
| Why does lost lung elastic recoil increase the tendency for airway collapse? |
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Definition
| The EPP moves towards unsupported airways towards the alveoli making the airways more collapsible |
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Term
| When there is non-uniformity of time constants in regards to alveoli emptying, air flow becomes asymmetric as breathing frequency __________? |
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Definition
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Term
| In determining the time constant for emptying a lung, what is the equation and how many time constants does it take for complete emptying? |
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Definition
| Resistance x Compliance = T, 4-5 constants to empty, 1 constant gives a 63% emptying |
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Term
| True or False: diagnostic tests should be used when diagnosis is plausible, but uncertain, and diagnosis will impact choice of therapy. |
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Definition
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Term
| If probability of a diagnosis is virtually certain on clinical grounds, should you test to confirm or treat the disease? |
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Definition
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Term
| What are the equations for sensitivity, specificity, likelihood ratio positive, likelihood ratio negative, and positive predictive value? |
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Definition
| Sensitivity - a/a+c, specificity - d/b+d, likelihood ratio positive - sens/1-spec, likelihood ratio negative - 1-sens/spec, and positive predictive value - a/a+b |
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Term
| Are asthma, bronchitis, emphysema, and upper airway abnormalities obstructive or restrictive problems? |
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Definition
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Term
| True or False: in a disease with increased lung recoil such as pulmonary fibrosis, the absolute peak flow is low due to inability to distend lung volume, but flow at a lower lung volume can be normal owing to increased recoil. |
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Definition
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Term
| True or False: TLC, FRC, and residual lung volume can be measured directly from spirometry just like other values. |
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Definition
| False, they require nitrogen washout or body plethysmography. |
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Term
| What happens to lung tidal volume as a person exercises? |
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Definition
| It increases in both amplitude and frequency |
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Term
| Conventionally what is minute ventilation defined as? |
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Definition
| Expired volume in L/min; also is the product of expired breath volume and breathing frequency |
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Term
| What is the respiratory exchange ratio, and what are the normal values in resting adults? |
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Definition
| The volume of CO2 eliminated divided volume of O2 extracted; normal is VCO2= .2 L/min VO2= .25 L/min with an RE ratio= .8 |
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Term
| True or False: physiological dead space is the sum of the volume of anatomical and alveolar dead space. |
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Definition
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Term
| What is the difference between hyperpnea and hyperventilation? |
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Definition
| Hyperpnea is an increase in ventilation, whereas hyperventilation refers to an increase in ventilation out of proportion to an increase in metabolic CO2 ventilation resulting in low arterial PCO2; high arterial PCO2 is hypoventilation |
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Term
| Which of these 3 affect the rate of diffusion within the alveolus - partial pressure gradient, diffusion coefficients, and geometry of the interface? |
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Definition
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Term
| Which gas, O2 or CO2, diffuses faster ns the gaseous phase and which is faster in a liquid phase? |
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Definition
| O2 in gaseous phase, and CO2 in liquid phase |
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Term
| The alveolar oxygen gradient, PA-aO2, which is normally <1 mmHg _________ when there is a reduction in pulmonary capillary transit time. |
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Definition
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Term
| Severe hypoxia can result from diffusion impairment, CO2 retention is _________ (commonly, rarely) a clinical problem. |
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Definition
| Rarely, because of ventilatory mechanisms which would result in low PO2 and normal PCO2 |
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Term
| Which of the following conditions result in insufficient time for O2 equilibrium to occur in capillary blood - decreased transit time, increased diffusion path length, reduction of capillary bed function, or reduced alveolar PO2. |
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Definition
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Term
| In an oxyhemoglobin curve what happens to O2 affinity when the curve shifts to the left or right? |
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Definition
| A left shift = greater affinity for O2 like in the lungs; a right shift = less affinity for O2 like in tissues. |
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Term
| Approx. 90% of CO2 is carried in arterial blood in what form? |
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Definition
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Term
| The more deoxygenated Hb is the _______ the amount of CO2 it can bind. |
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Definition
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Term
| List 3 reasons for pulmonary edema which reduces lung compliance. |
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Definition
| Increased pul. Cap. Pressure (left HF), reduced plasma oncotic pressure (hypoproteinuria), leaky alveolar-cap membranes letting proteins extravasate. |
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Term
| Why is alveolar pressure made positive in mechanical ventilation with addition of positive end-expiratory pressure? |
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Definition
| The pressure is transmitted to interstitial place to prevent edema by maintaing hydrostatic pressure gradient. |
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Term
| What is the ideal ventilation/perfusion ratio? |
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Definition
| .8, 4L/min alveolar ventilation over 5L/min of cardiac output; higher ratios occur at the top of the lung and vice versa |
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Term
| Perfusion pressures are ______ at the top of the lung and _______ at the bottom of the lung. |
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Definition
| Lesser, greater; gravity is a major factor |
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Term
| What is the difference between a shunt and dead space in the lung? |
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Definition
| Shunt = no ventilation, dead space = no perfusion |
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Term
| What are the body’s reflex adjustments for low V/Q ratios and high V/Q ratios respectively? |
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Definition
| Low - vasoconstriction to reduce perfusion, high - bronchoconstriction to reduce ventilation |
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Term
| Describe the PO2 and PCO2 (either low, normal, high) in lung regions with low, normal, and high V/Q ratios. |
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Definition
| Low - low O2, high CO2; Normal - normal O2 & CO2; High - high O2, low PCO2 |
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Term
| There is a limit to V/Q ratio compensation mismatch. Describe what happens in low V/Q regions versus high V/Q regions in regards to PO2 and O2 content being low, normal or high. |
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Definition
| Low - low PO2, low O2 content; high - high PO2, only slightly increased O2 content |
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Term
| The ventral respiratory group are located in the __________ __________ and associated with retrofacial nucleus (RFN/BotC), nucleus ambiguous (NA) and nucleus retroambigualis (NRA). The VRG has both __________ and ________ neurons and many cross the midline to provide rhythmical stimulation to the ________ and _______ motorneurons. |
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Definition
| Ventrolateral medulla, inspiratory and expiratory, phrenic and thoracic |
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Term
| The dorsal respiratory group form the _________ ________ of the tractus solitarius in the dorsomedial medulla. They are primarily _________ neurons. Some are excited by lung inflammation whereas others mimic the activity of slow-adapting pulmonary stretch receptors. Many DRG meurons have axons which cross the midline and provide inspiratory-phase _________ of the ________ motorneurons. |
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Definition
| Ventrolateral nucleus, inspiratory, excitation, phrenic |
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Term
| The Pontine respiratory group (PRG) lies in the _________ ______ in the mucleus parabrachialis medialis and Kolliker Fuse. They have inspiratory, expiratory and I-E phase spanning activity. The __________ _________ __________ seems to be important in switching from inspiration to expiration and vice versa. |
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Definition
| Dorsolateral pons, I-E phase spanning activity. |
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Term
| Lesion of the PRG cause _________ or __________ breathing in patients. |
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Definition
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Term
| Which area of the VRG is responsible for generating respiratory rhytym? |
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Definition
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Term
| What are the 3 areas of the upper airway that have receptors for breathing reflex mechanisms? |
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Definition
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Term
| Pulmonary vagal mechanisms have which 3 types of receptors and they exert their primary effects on what? |
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Definition
| Slow adapting stretch receoptors, rapidly adapting receptors, and juxtapulmonary capillary receptors and they affect breathing pattern. |
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Term
| The slowly adapting stretch receptors are located in smooth airway muscle, through which nerve is their activity conveyed and what is their function? |
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Definition
| They are activated through the vagus nerve and they promote inspiratory termination |
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Term
| Rapidly adapting airway receptors are located in the airway epithelium, what are they stimulated by and what do they cause? |
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Definition
| Stimulated by inhaled irritants and local mechanical distortion to cause hyperpnea. |
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Term
| The juxtapulmonary capillary receptors are located in the alveolar-capillary interstitial space, what are they stimulated by and what is the result of stimulation? |
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Definition
| Stimulated by interstitial distortion, congestion, and pulmonary emboli to cause tachypnea. |
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Term
| What are the two types of chest wall mechanoreceptors that coordinate breathing during changes of posture and speech? |
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Definition
| Muscle spindles, and golgi tendon organs |
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Term
| Golgi tendon mechanoreceptors are primarily found in the diaphragm, respond to muscle tension, and __________ respiratory motorneurons. |
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Definition
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Term
| Muscle spindle mechanoreceptors are primarily located in the intrafusal muscle fibers of the intercostals muscles, respond to stretch, and stabilize ventilation by what action? |
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Definition
| Stimulating respiratory motorneurons. |
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Term
| Peripheral sensory afferents from muscle spindles, proprioreceptors, and free nerve endings have what affect on ventilation when stimulated? |
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Definition
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Term
| The chemosensitive regions of the ventrolateral medulla increase ventilation in response to what two mechanisms? |
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Definition
| Increased local [H+] and an increase in PCO2 which raises CSF CO2 which then raises [H+] for CSF. |
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Term
| True or False: hypoxia is a direct stimulant of chemosensitive regions. |
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Definition
| False, indirect stimulant when hypoxia is extreme and lactic acidosis forms. |
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Term
| Peripheral chemoreceptors in the carotid bifurcation increase ventilation when what 3 things occur? |
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Definition
| Reduced PaO2, increased PaCO2, increased arterial H+ |
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Term
| If PaO2 is sufficiently low (60mm Hg) hypoxia causes a hyperbolic increase in ventilation, what two things can increase or decrease the potency of this stimulus? |
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Definition
| High PCO2 increases stimulus to ventilate, low PCO2 decreases stimulus |
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Term
| ____________ increases the CO2 stimulus to increase ventilation through stimulation of the carotid bodies, whereas __________ inactivates the carotid bodies and the ventilation-CO2 relationship is primarily determined by central chemoreceptors. |
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Definition
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Term
| Metabolic acidosis, and therefore increased [H+], stimulates ventilation mediated exclusively by the __________ __________. |
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Definition
| Carotid bodies; when metabolic acidosis is present ventilation is higher than normal at any given level of PCO2 |
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Term
| Which of these 3 are the result of chronic hypoxia - polycythemia (more red blood cells), increased 2,3 DPG, and pulmonary hypertension. |
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Definition
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Term
| There is a primary and secondary ventilatory responses to an increase in altitude, what are they? |
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Definition
| Primary, stimulation of ventilation but attenuates as respiratory alkalosis develops, PCO2 falls; secondary, 2-3 days low plasma [HCO3] occurs due to excretion because of low PCO2, this metabolic compensation corrects blood pH and also increases response to hypoxia again (due to rising [H+]) via carotid bodies. |
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Term
| True or False: as far as chemoreceptor assignments, the central receptors detect 75% of PCO2, whereas the peripheral carotid bodies detect 25% PCO2, PO2, and H+. |
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Definition
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Term
| Patients with chronic lung disease become insensitive to chronically elevated PCO2 so that their ventilation is primarily stimulated by _________. |
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Definition
| Hypoxia, however, giving oxygen to the patient reduces ventilatory drive and increases PaCO2. |
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Term
| Understand how the oxyhemoglobin curve shifts with different affectors and what the results are for a left shift and a right shift. |
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Definition
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Term
| Be able to recite pressures from all chambers of the heart, as well as the systemic and pulmonic arteries, capillaries, and veins. |
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Definition
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Term
| True or False: COPD can describe emphysema, chronic bronchitis, respiratory bronchiloitis and more. |
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Definition
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