McqMate
Chapters
1. |
Which is CORRECT? |
A. | voluntary control of breathing originates in the pons/medulla |
B. | automatic breathing control descends to the respiratory musculature via the corticospinal tract |
C. | the reciprocal innervation in automatic breathing is via descending pathways rather than spinal reflexes |
D. | automatic fibres descend to innervate the external intercostal muscles at each thoracic level to mediate expiration |
E. | there is no output to the phrenic nerves during expiration |
Answer» C. the reciprocal innervation in automatic breathing is via descending pathways rather than spinal reflexes |
2. |
Which abolishes automatic respiration? Destruction of: |
A. | pre-Bottzinger complexes |
B. | ventral gp respiratory neurons |
C. | dorsal gp respiratory neurons |
D. | section at the inferior border of the pons |
E. | transaction rostral to the pons |
Answer» A. pre-Bottzinger complexes |
3. |
Which does not stimulate carotid bodies? |
A. | carbon monoxide poisoning |
B. | cyanide poisoning |
C. | hypoxia |
D. | hypercapnia |
E. | increased H+ concentration |
Answer» A. carbon monoxide poisoning |
4. |
All of the following shift the Hb dissociation curve to the right during exercise EXCEPT: |
A. | increased 2,3 DPG |
B. | increased pCO2 |
C. | increased temperature |
D. | decreased pO2 |
E. | increased H+ concentration |
Answer» D. decreased pO2 |
5. |
Hypoxia at high altitudes: |
A. | is a form of stagnant hypoxia |
B. | causes symptoms of cyanosis |
C. | causes severe symptoms in an unacclimatised person at 3,000m |
D. | can always be reversed with 100% O2 |
E. | increased H+ concentration |
Answer» B. causes symptoms of cyanosis |
6. |
Regarding surfactant: |
A. | infant respiratory distress syndrome can be adequately treated with administration of phospholipids alone |
B. | cigarette smokers have the same amount of surfactant as non-smokers |
C. | the phospholipid film is formed by tubular myelin |
D. | infant respiratory distress syndrome is caused by insufficient surfactant that prevents the alveoli from expanding at first inspiratory effort |
E. | formation of the phospholipid film is greatly facilitated by the carbohydrate in surfactant |
Answer» C. the phospholipid film is formed by tubular myelin |
7. |
Regarding the work of breathing during quiet inspiration: |
A. | elastic work = 80% |
B. | viscous resistance = 7% |
C. | airway resistance = 13% |
D. | when tidal volume versus intrapleural pressure in quiet inspiration are plotted, a straight line results |
E. | the amount of elastic work required to inflate the whole respiratory system is more than the amount required to inflate the lungs alone |
Answer» B. viscous resistance = 7% |
8. |
Regarding gas exchange in the lungs: |
A. | PaO2 in pulmonary capillaries is the same as PaO2 in the aorta |
B. | diffusing capacity for O2 (DLO2) increases from 25→65ml/min/mmHg during exercise |
C. | DLO2 is unaffected by beryllium poisoning and sarcoidosis |
D. | CO2 retention is frequently a problem in patients with alveolar fibrosis |
E. | decreased secretion of PDGF by alveolar macrophages causes pulmonary fibrosis |
Answer» B. diffusing capacity for O2 (DLO2) increases from 25→65ml/min/mmHg during exercise |
9. |
Regarding gas exchange in the lungs: |
A. | N2O is diffusion limited |
B. | CO is perfusion limited |
C. | O2 is between N2O and CO but at rest, is perfusion limited |
D. | diffusing capacity of the lung for a gas is inversely proportionate to the surface area of the alveolocapillary membrane and directly proportional to its thickness |
E. | at rest, it takes blood 0.25secs to traverse the pulmonary capillaries |
Answer» C. O2 is between N2O and CO but at rest, is perfusion limited |
10. |
Regarding bronchial tone: |
A. | substance P causes bronchoconstriction |
B. | constriction is caused by sympathetic discharge |
C. | dilation is caused by parasympathetic discharge |
D. | maximal bronchoconstriction occurs at 4am |
E. | VIP causes bronchoconstriction |
Answer» A. substance P causes bronchoconstriction |
11. |
Regarding pulmonary function, which of the following is NOT true? |
A. | FRC = ERV + RV |
B. | IRV in men is about 3,3L |
C. | RV in women is about 1.1L |
D. | inspiratory capacity in men = 4.8L |
E. | total lung capacity = 6L in men, 4.2L in women |
Answer» D. inspiratory capacity in men = 4.8L |
12. |
Regarding the glottis: |
A. | when laryngeal adductors are paralysed there is inspiratory stridor |
B. | abductors contract early in inspiration |
C. | when abductors are paralysed, aspiration pneumonia may result |
D. | the adductors are supplied by the vagus nerves, the abduction by the hypoglossal nerve |
E. | in animals with bilateral cervical vagotomy, pulmonary oedema is purely secondary to aspiration |
Answer» B. abductors contract early in inspiration |
13. |
Regarding oxygen transport: |
A. | Haemoglobin S has glutamic acid instead of valine in the β chains |
B. | the O2 saturation of Hb is the percentage of available binding sites that do not have O2 attached |
C. | the oxygenated form of Hb is the T state |
D. | cyanosis is more obvious in anaemic patients |
E. | normal P50 is 27mmHg |
Answer» E. normal P50 is 27mmHg |
14. |
Regarding the O2 dissociation curve: |
A. | O2 affinity of Hb is reduced when the curve is shifted to the left |
B. | decreased 2,3-DPG shifts the curve to the right |
C. | the Bohr effect is attributed to the action of PCO2 on H+ concentration |
D. | temperature has no effect on the curve |
E. | 2,3-DPG levels are reduced at altitude |
Answer» C. the Bohr effect is attributed to the action of PCO2 on H+ concentration |
15. |
Diffusion is inversely proportional to: |
A. | the diffusion constant |
B. | tissue area |
C. | solubility of the gas |
D. | square root of the molecular weight |
E. | the difference in partial pressure |
Answer» D. square root of the molecular weight |
16. |
In exercise: |
A. | oxygen consumption is about 6L/min in a moderately fit subject |
B. | the respiratory exchange ratio rises to 0.8 |
C. | diffusing capacity increases 3-fold |
D. | the change in cardiac output is only about a sixth of the increase in ventilation |
E. | the oxygen dissociation curve moves to the left |
Answer» C. diffusing capacity increases 3-fold |
17. |
Central respiratory chemoreceptors: |
A. | are located in the medulla near exit of cranial nerve X, XI |
B. | respond directly to changes in external PCO2 |
C. | respond directly to changes in arterial PO2 |
D. | are located on dorsal surface of medulla |
E. | respond to pH of CSF |
Answer» E. respond to pH of CSF |
18. |
Respiratory peripheral chemoreceptors: |
A. | carotid bodies respond to PO2, PCO2, and pH |
B. | peripheral chemoreceptor response to arterial PCO2 is more important than central chemoreceptor response |
C. | aortic bodies are located within the aortic valve ring |
D. | drop in PO2 < 100mmHg causes increase in firing rate |
E. | carotid bodies respond to venous PO2 |
Answer» D. drop in PO2 < 100mmHg causes increase in firing rate |
19. |
Ventilatory response to CO2 is reduced by all EXCEPT: |
A. | sleep |
B. | barbiturate overdose |
C. | increasing age |
D. | decreasing the work of breathing |
E. | trained athletes and divers |
Answer» D. decreasing the work of breathing |
20. |
The surface area of the lungs is: |
A. | three times the area of skin |
B. | ten times the area of skin |
C. | 30 times the area of skin |
D. | 100 times the area of skin |
E. | none of the above |
Answer» C. 30 times the area of skin |
21. |
Site of most / major airway resistance is: |
A. | trachea |
B. | main bronchi |
C. | large bronchi |
D. | medium sized bronchi |
E. | bronchioles |
Answer» D. medium sized bronchi |
22. |
The volume of the anatomical dead space is: |
A. | 50mL |
B. | 100mL |
C. | 150mL |
D. | 200ml |
E. | 300ml |
Answer» C. 150mL |
23. |
Which respiratory volume is INCORRECT? |
A. | tidal volume is the normal breathing volume |
B. | vital capacity is the volume from maximal inspiration followed by maximal expiration |
C. | residual volume is the volume remaining in lungs after maximal expiration |
D. | functional residual capacity is the volume after normal inspiration |
E. | total lung capacity is the vital capacity plus residual volume |
Answer» D. functional residual capacity is the volume after normal inspiration |
24. |
The diffusion constant is proportional to: |
A. | tissue thickness |
B. | square root of the molecular weight |
C. | difference in partial pressures |
D. | tissue area |
E. | gas solubility |
Answer» E. gas solubility |
25. |
Mean pressure (mmHg) in the main pulmonary artery is: |
A. | 2 |
B. | 5 |
C. | 8 |
D. | 15 |
E. | 25 |
Answer» D. 15 |
26. |
Regarding pulmonary blood flow: |
A. | increased arterial pressure leads to increased pulmonary vascular resistance |
B. | localised vasoconstriction is directly due to arterial PO2 hypoxia |
C. | regional differences are due to hydrostatic pressure differences |
D. | at the apex Pa>Pv>PA |
E. | pulmonary arteries and veins have transmural pressures equal to alveolar pressure |
Answer» C. regional differences are due to hydrostatic pressure differences |
27. |
Which is not inactivated by the lungs? |
A. | serotonin |
B. | bradykinin |
C. | leukotrienes |
D. | prostaglandin E2 |
E. | vasopressin |
Answer» E. vasopressin |
28. |
Regarding the alveolar gas equation: |
A. | the respiratory quotient nears 1.0 with exercise |
B. | PIO2= barometric pressure – water vapour pressure |
C. | PACO2 > PaCO2 |
D. | PAO2 is normally 150mmHg |
E. | remains valid if there is CO2 present in the inspired gas |
Answer» A. the respiratory quotient nears 1.0 with exercise |
29. |
The amount of O2 in blood with a PaO2 of 100mmHg is: |
A. | 0.003ml O2/100ml |
B. | 0.3ml O2/100ml |
C. | 3ml O2/100ml |
D. | 3ml O2/mL |
E. | 0.3ml O2/L |
Answer» B. 0.3ml O2/100ml |
30. |
Regarding the O2 dissociation curve: |
A. | increased PCO2 has a direct effect on the curve, shifting it to the right |
B. | 2,3-DPG levels rise as altitude |
C. | the deoxy form of Hb is in the relaxed state |
D. | CO moves the curve to the left as it has 100 times the affinity of O2 for Hb |
E. | P50 is at a PO2 of 40mmHg |
Answer» B. 2,3-DPG levels rise as altitude |
31. |
Which respiratory principle is INCORRECT? |
A. | Fick’s law states that “the volume of gas per unit time that moves across a sheet of tissue is proportional to the area of the sheet, but inversely proportional to its thickness” |
B. | the Bohr effect is “the effect of PCO2 on the O2 dissociation curve due to the action of PCO2 on H+ concentration” |
C. | Henry’s law states that “the amount of gas dissolved is proportional to the partial pressure of that gas” |
D. | the chloride shift is “the diffusion of HCO3 - in to the cell, with the outward diffusion of Cl- ions to maintain electrical neutrality” |
E. | the Haldane effect is that deoxygenation of the blood increases its ability to carry CO2 |
Answer» D. the chloride shift is “the diffusion of HCO3 - in to the cell, with the outward diffusion of Cl- ions to maintain electrical neutrality” |
32. |
Given a PCO2 = 600mmHg and a HCO3- = 28mEq/l there is a: |
A. | metabolic acidosis |
B. | metabolic acidosis with renal compensation |
C. | respiratory acidosis |
D. | respiratory acidosis with renal compensation |
E. | respiratory alkalosis |
Answer» C. respiratory acidosis |
33. |
Regarding the elastic properties of the lung: |
A. | the lung volume at any given pressure during inflation is larger than during deflation |
B. | the area under the pressure-volume curve is known as the compliance |
C. | surface tension is the force acting across an imaginary line in the surface of the liquid |
D. | pressure generated in an alveolus equals 4T/R |
E. | surfactant, produced by Type I alveolar cells, reduces surface tension in alveoli |
Answer» C. surface tension is the force acting across an imaginary line in the surface of the liquid |
34. |
Halving the radius of an airway increases resistance: |
A. | 2-fold |
B. | 4-fold |
C. | 8-fold |
D. | 16-fold |
E. | has no effect on resistance |
Answer» D. 16-fold |
35. |
The major site of resistance in the bronchial tree is the: |
A. | segmental bronchii |
B. | medium-sized bronchii |
C. | small bronchii |
D. | large bronchioles |
E. | terminal bronchioles |
Answer» B. medium-sized bronchii |
36. |
Lung compliance increases with: |
A. | asthma |
B. | alveolar oedema |
C. | pulmonary hypertension |
D. | atelectasis |
E. | pulmonary fibrosis |
Answer» A. asthma |
37. |
The ventilatory response to CO2 is increased by: |
A. | sleep |
B. | increasing age |
C. | trained athlete |
D. | morphine |
E. | decreased PO2 |
Answer» E. decreased PO2 |
38. |
Normally the FEV1 is what percentage of FVC? |
A. | 50% |
B. | 60% |
C. | 70% |
D. | 80% |
E. | 90% |
Answer» D. 80% |
39. |
The calibre of extra-alveolar vessels is primarily determined by: |
A. | the difference between alveolar pressure and the pressure within them |
B. | the pressure in the pulmonary artery |
C. | the lung volume |
D. | the cardiac output |
E. | the patient’s fluid status |
Answer» C. the lung volume |
40. |
Which statement regarding hyperbaric oxygen therapy is INCORRECT? |
A. | males eliminate carboxy haemoglobin faster than females |
B. | gas around the body is normal air compressed to the same high pressure |
C. | it produces marked increases in dissolved oxygen in the blood |
D. | oxygen is administered at up to 3 atmospheres pressure |
E. | toxicity includes optic neuritis |
Answer» A. males eliminate carboxy haemoglobin faster than females |
41. |
All of the following are features of acclimatisation to high altitude EXCEPT: |
A. | shift to the right of the oxygen dissociation curve |
B. | increased number of capillaries in peripheral tissues |
C. | pulmonary vasodilation |
D. | polycythaemia |
E. | increased maximum breathing capacity |
Answer» C. pulmonary vasodilation |
42. |
Which of the following statements is TRUE? |
A. | pulmonary stretch receptors lie within the airway epithelial cells |
B. | J receptors, when stimulated, cause slow deep breathing |
C. | irritant receptors, when stimulated, send impulses up the vagus in unmyelinated fibres |
D. | irritant receptors are rapidly adapting |
E. | increased maximum breathing capacity |
Answer» D. irritant receptors are rapidly adapting |
43. |
Which one of the following statements regarding ventilation is INCORRECT? |
A. | tidal volume in the average human is 500ml |
B. | anatomical dead space is the volume of the conducting airway and is about 160ml |
C. | upper regions of the lung ventilate better than the lower regions |
D. | you can measure physiological dead space via Bohr’s method to get what is called a Bohr equation which is: VD PACO2-PECO2 VT PACO2 |
E. | None of the above |
Answer» C. upper regions of the lung ventilate better than the lower regions |
44. |
The diffusion capacity (DI) of the lung accounts for: |
A. | P1-P2 |
B. | area of lung |
C. | the thickness |
D. | diffusion constant |
E. | all of the above |
Answer» A. P1-P2 |
45. |
Regarding movement to high altitude, which statement is INCORRECT? |
A. | hyperventilation occurs due to hypoxic stimulation of peripheral chemoreceptors |
B. | pro-erythroblasts mature into erythrocytes more rapidly than normal |
C. | renal bicarbonate excretion increases |
D. | increased numbers of mitochondria appear in the tissues |
E. | FiO2 decreases with increasing altitude |
Answer» E. FiO2 decreases with increasing altitude |
46. |
Metabolic functions of the lung include all of the following EXCEPT: |
A. | conversion of AI to AII by ACE |
B. | metabolism of AII |
C. | inactivation of bradykinin |
D. | removal of serotonin |
E. | metabolism of arachidonic acid metabolises |
Answer» B. metabolism of AII |
47. |
Which of the following is INCORRECT? |
A. | O2 toxicity causes convulsion |
B. | O2 at 100% in premature infants causes retrolental fibroplasia |
C. | acclimatisation to high altitudes include a shift to the left of the O2 dissociation curve |
D. | polycythaemia is a feature of acclimatisation |
E. | acute mountain sickness is due to hypoxaemia and alkalosis |
Answer» C. acclimatisation to high altitudes include a shift to the left of the O2 dissociation curve |
48. |
Regarding the neural control of breathing, which statement is INCORRECT? |
A. | medullary centres are close to but separate from central chemoreceptors |
B. | during quiet respiration, expiration is a passive event |
C. | inspiratory medullary neurons supply both phrenic nerves |
D. | ventral medullary neurons are expiratory and do not discharge spontaneously |
E. | inspiratory medullary neurons discharge spontaneously at a rate of 12-15 times/minute |
Answer» D. ventral medullary neurons are expiratory and do not discharge spontaneously |
49. |
The transport of which of the following gases is DIFFUSION LIMITED? |
A. | O2 |
B. | N2O |
C. | CO2 |
D. | CO |
E. | halothane |
Answer» D. CO |
50. |
With regard to anatomic dead space, all of the following are true EXCEPT: |
A. | it is calculated by Bohr’s method |
B. | the normal value is about 150ml |
C. | it increases with large inspirations |
D. | depends on the size of the subject |
E. | it is equivalent to the conducting zone |
Answer» A. it is calculated by Bohr’s method |
51. |
Which of the following is INCORRECT? |
A. | haemoglobin S causes the O2 curve to shift to the left |
B. | the O2 dissociation curve is shifted to the right by an increased PCO2, H+ concentration and temperature |
C. | carboxy haemoglobin has 240 times the affinity of O2 for Hb |
D. | COHB shift the O2 dissociation over to the left |
E. | it is equivalent to the conducting zone |
Answer» A. haemoglobin S causes the O2 curve to shift to the left |
52. |
Regarding the chemical control of breathing, which statement is INCORRECT? |
A. | central chemoreceptors are located in the medulla oblongata |
B. | hypoxia makes an individual more sensitive to increases in arterial carbon dioxide |
C. | arterial oxygen less than 70mmHg markedly stimulates respiration via the carotid bodies |
D. | carotid bodies have the highest blood flow, per unit time per 100g, of any tissue in the body |
E. | carbon dioxide is more important than oxygen in respiratory control |
Answer» C. arterial oxygen less than 70mmHg markedly stimulates respiration via the carotid bodies |
53. |
Fick’s law states that: |
A. | Va = (VCO2/PCO2) x K |
B. | V = (A.D.(P1 – P2))/T |
C. | pH - -LOG[H+] |
D. | P1V1 = P2V2 |
E. | V1/V2 = T1/2 |
Answer» B. V = (A.D.(P1 – P2))/T |
54. |
Regarding surfactant, which statement is INCORRECT? |
A. | it predominantly consists of phospholipid |
B. | it is increased by long-term 100% oxygen therapy |
C. | hydrophobic “tails” face into alveolar lumen |
D. | it is decreased by cigarette smoking |
E. | pulmonary oedema is a consequence of its absence |
Answer» B. it is increased by long-term 100% oxygen therapy |
55. |
Which of the following DOES NOT shift the O2 dissociation curve to the right? |
A. | increased temperature |
B. | increased PCO2 |
C. | increased H+ |
D. | increased DPG |
E. | increased carboxy haemoglobin |
Answer» E. increased carboxy haemoglobin |
56. |
Regarding exercise, which statement is INCORRECT? |
A. | the energy cost of breathing is up to 10% of total energy expenditure |
B. | total pulmonary ventilation increases by up to 20 fold |
C. | total oxygen consumption increases by up to 20 fold |
D. | total carbon dioxide production increases by up to 40 fold |
E. | P5O increases |
Answer» A. the energy cost of breathing is up to 10% of total energy expenditure |
57. |
Total lung capacity is equal to: |
A. | vital capacity + tidal volume |
B. | vital capacity + functional residual capacity |
C. | tidal volume + residual volume |
D. | functional residual capacity + tidal volume |
E. | vital capacity + residual volume |
Answer» E. vital capacity + residual volume |
58. |
Regarding compliance, which statement is INCORRECT? |
A. | functional residual capacity is the equilibrium volume when elastic recoil of lung is balanced by normal tendency for chest wall to spring out |
B. | hysteresis is due to frictional resistance to air movement |
C. | compliance is greater in expiration than in inspiration |
D. | compliance is increased in emphysema |
E. | compliance is a dynamic measure of lung and chest wall recoil |
Answer» E. compliance is a dynamic measure of lung and chest wall recoil |
59. |
Which of the following is NOT involved in the control of ventilation? |
A. | peripheral chemoreceptors |
B. | lung stretch receptors |
C. | basal ganglia |
D. | pons |
E. | respiratory muscles |
Answer» C. basal ganglia |
60. |
Which of the following DOES NOT decrease lung compliance? |
A. | left ventricular failure |
B. | atelectasis |
C. | pulmonary fibrosis |
D. | advancing age |
E. | raised pulmonary capillary wedge pressure |
Answer» D. advancing age |
61. |
Regarding ventilation / perfusion (V/Q) relationships, which statement is INCORRECT? |
A. | V/Q ratio is greatest at the lung apex |
B. | V/Q ratio is about one at level of third rib when upright |
C. | ventilation decreases proportionately more than perfusion from base to apex |
D. | V/Q ratio for whole lung at rest is about 0.8 |
E. | exercise increases the V/Q ratio |
Answer» C. ventilation decreases proportionately more than perfusion from base to apex |
62. |
Regarding pulmonary perfusion, which statement is INCORRECT? |
A. | apical perfusion is less than basal |
B. | E.coli endotoxin causes venodilatation |
C. | total pulmonary blood flow increases 3-6 fold during exercise |
D. | pulmonary vascular resistance increases at small lung volumes |
E. | in zone 2, pulmonary arterial pressure is greater than alveolar pressure |
Answer» B. E.coli endotoxin causes venodilatation |
63. |
Regarding pulmonary ventilation, which statement is INCORRECT? |
A. | physiological dead space is normally larger than anatomical dead space |
B. | basal ventilation is greater than apical |
C. | normal tide volume is about 7ml/kg |
D. | airway resistance decreases at large lung volumes |
E. | total pulmonary ventilation can increase by up to 20 fold during exercise |
Answer» A. physiological dead space is normally larger than anatomical dead space |
64. |
Which of the following DOES NOT constrict pulmonary arterioles? |
A. | adrenaline |
B. | thromboxane B2 |
C. | noradrenaline |
D. | prostaglandin F2 α |
E. | isoproteronol |
Answer» E. isoproteronol |
65. |
Regarding the lung volumes in a healthy 70kg male, 183cm tall, which is INCORRECT? |
A. | tidal volume = 500ml |
B. | residual volume = 1200ml |
C. | expiratory reserve volume = 1000ml |
D. | inspiratory capacity = 3300ml |
E. | vital capacity = 4800ml |
Answer» D. inspiratory capacity = 3300ml |
66. |
Regarding carbon dioxide transport in blood, which statement is INCORRECT? |
A. | oxygen is about 20 times less soluble in blood |
B. | deoxygenation of blood increase its ability to carry carbon dioxide |
C. | arterial blood transports about 20% in dissolved form |
D. | venous blood has higher haematocrit than arterial blood |
E. | carbamino compounds are formed by reaction with both plasma proteins and Hb |
Answer» C. arterial blood transports about 20% in dissolved form |
67. |
Which of the following does NOT increases synthesis of 2, 3-DPG? |
A. | growth hormone |
B. | phosphate deficiency |
C. | thyroid hormone |
D. | exercise for one hour |
E. | androgens |
Answer» B. phosphate deficiency |
68. |
Which of the following DOES NOT shift the oxygen-haemoglobin dissociation curve to the right? |
A. | decreased phosphate |
B. | increased altitude |
C. | cortisol |
D. | decreased pH |
E. | aldosterone |
Answer» A. decreased phosphate |
69. |
Regarding alveolar cells, which statement is INCORRECT? |
A. | type I pneumocytes repair alveolar epithelium |
B. | pulmonary alveolar macrophages are derived from blood monocytes |
C. | mast cell membranes bind IgE via Fc portion to heavy chain |
D. | APUD (neuroendocrine) cells are of endodermal origin |
E. | type II pneumocytes are membranous |
Answer» E. type II pneumocytes are membranous |
70. |
Which of the following substances is NOT removed from the blood by the lung? |
A. | prostaglandins |
B. | noradrenaline |
C. | acetylcholine |
D. | adrenaline |
E. | bradykinin |
Answer» D. adrenaline |
71. |
Which statement regarding gas exchange in the lungs is INCORRECT? |
A. | gases generally cross by simple diffusion |
B. | diffusion capacity for carbon dioxide is much greater than for oxygen |
C. | nitrous oxide is a diffusion limited gas |
D. | carbon monoxide does not reach equilibrium in 0.75 seconds |
E. | oxygen is a perfusion limited gas |
Answer» C. nitrous oxide is a diffusion limited gas |
72. |
Which of the following substances is NOT synthesised by the lung? |
A. | prostaglandins |
B. | serotonin |
C. | dipalmityl phosphatidylcholine |
D. | histamine |
E. | kallikrein |
Answer» B. serotonin |
73. |
Exercise has all of the following effects on blood gases EXCEPT: |
A. | increased PACO2 |
B. | increased PAO2 |
C. | unchanged PaCO2 |
D. | unchanged PaO2 |
E. | increased PvCO2 |
Answer» A. increased PACO2 |
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