Respiratory System Most Important MCQs

1 - A decrease in the arterial PO2 is seen in______________?

A. Decrease in hemoglobin concentration of arterial blood

B. Paralysis of inspiratory muscles

C. Sluggish blood flow

D. High altitudes

High altitudes

2 - Alveolar O2 tension is______________?

A. Increased by hyperventilation

B. Decreased by hyperventilation

C. Similar to venous O2 tension

D. Not affected by respiratory depression

Increased by hyperventilation

3 - An important non- respiratory function of lungs is_____________?

A. Anion balance

B. Sodium balance

C. Potassium balance

D. Ca+2 balance

Sodium balance

4 - Arterial O2 content is reduced in one of following ______________?

A. Stagnant hypoxia

B. Anemic hypoxia

C. Histotoxic hypoxia

D. Hypoxic or arterial hypoxia

Anemic hypoxia

5 - Arterial PO2 is reduced in_____________?

A. Anemia

B. KCN poisoning

C. Pulmonary hypoventilation

D. CO poisoning

Pulmonary hypoventilation

6 - At high altitudes the following changes takes place except_______________?

A. Increase in respiratory rate

B. Increases in depth of respiration

C. Increase in oxygen carrying capacity of blood

D. Increase in partial pressure of CO2

Increase in partial pressure of CO2

7 - Bronchial circulation is associated with__________________?

A. Air conditioning

B. Drug absorption

C. Gaseous exchange

D. Reserve volume

Gaseous exchange

8 - Carbon monoxide poisoning causes_______________?

A. Hypoxic hypoxia

B. Oxygen dissociation curve shifts to left

C. Cyanosis

D. Diffusion capacity of lungs decreases

Oxygen dissociation curve shifts to left

9 - Carotid body function in an organ work as_______________?

A. Differential pressure of oxygen in arterial blood

B. Differential pressure of oxygen in venous blood

C. Differential pressure of oxygen in in tissue fluids

D. Differential pressure of oxygen in in hemoglobin synthesis

Differential pressure of oxygen in arterial blood

10 - Cyanosis or bluish coloration of skin and mucus membrane depends upon______________?

A. The relative proportion of reduced and oxygenated hemoglobin

B. The absolute amount of reduced hemoglobin

C. Thickness of the skin

D. Fragility of capillaries

The absolute amount of reduced hemoglobin

11 - During inspiration when the diaphragm contracts, the intrapleural pressure becomes_____________?

A. More negative

B. Less negative

C. Positive

D. Equal to the intra alveolar pressure

More negative

12 - During the initial part of inspiration, which of the following does not occur ?

A. Intrapulmonary pressure falls

B. Intra thoracic pressure rises

C. Intra-abdominal pressure rises

D. The partial pressure of O2 in dead space rises

Intra thoracic pressure rises

13 - Energy expenditure during normal breathing____________?

A. 25% – 50% of total energy spent

B. 50% -75% of total energy spent

C. 15% – 20% of total energy spent

D. 2% – 3% of total energy spent

2% – 3% of total energy spent

14 - Hypoxia is characterized by ___________?

A. Low arterial PO2

B. Intense chemoreceptor response

C. Favorable response to 100% oxygen

D. All of the above

All of the above

15 - In cases of hypercapnia there is_______________?

A. Increased pH of blood

B. Decreased pH of blood

C. Remains same

D. Increased oxygen concentration in blood

Decreased pH of blood

16 - In Haldane effect CO2 dissociation curve is shifted to_____________?

A. Left

B. Right

C. Does not shift

D. None of the above

Right

17 - In which of the following diseases would you expect to find an increase in thickness of the respiratory membrane ?

A. Emphysema

B. Asthma

C. Pulmonary artery thrombosis

D. Skeletal abnormalities of the chest

Emphysema

18 - Inability of exchange of oxygen through lung tissue if known as____________?

A. Anoxic anoxia

B. Anoxia

C. Histotoxic hypoxia

D. Ischemic hypoxia

Histotoxic hypoxia

19 - Increase in partial pressure of CO2 leading to release of oxygen to the tissues is________________?

A. Haldane effect

B. Bohr effect

C. Breur effect

D. Hamburger effect

Bohr effect

20 - Kussmamul's respiration occurs in response to_______________?

A. Decrease in pH of blood

B. Increase in pH of blood

C. Obstructive pulmonary disease

D. Carbon monoxide poisoning

Decrease in pH of blood

21 - Limitation of inspiration by vagal lung inflation signals is called the______________?

A. Autonomic reflex

B. Bainbridge reflex

C. Herring – Breur reflex

D. Dynamic stretch reflex

Herring – Breur reflex

22 - Most effective method of assessing breathing is by measuring____________?

A. Tidal volume

B. Respiratory rate

C. Alveolar ventilation

D. FEV 1

FEV 1

23 - Muscle of expiration____________?

A. Diaphragm

B. Internal intercostals

C. External intercostals

D. Rcti Abdominis

Internal intercostals

24 - Non- respiratory function of the lung is_________________?

A. Dopamine metabolism

B. Adrenaline metabolism

C. Serotonin metabolism

D. PGE2 production

Serotonin metabolism

25 - Normal intrapleural pressure during the start of inspiration is _________ mm of Hg?

A. -2

B. -5

C. 0

D. -7

-2

26 - Oxygen affinity decreases in_________________?

A. Hypoxia

B. Hypothermia

C. HbF

D. Increased pH

Hypoxia

27 - Oxygen affinity is increased by all except_________________?

A. Alkalosis

B. Hypoxia

C. Increased HbF

D. Hypothermia

Hypoxia

28 - Oxygen as an emergency drug is contraindicated in______________?

A. Anaphylaxis

B. Asthma

C. Hyperventilation

D. COPD

Hyperventilation

29 - Oxygen dissociation cure is shifted to the right in all except_____________?

A. Fall in pH

B. Rise in temperature

C. Increase of 2, 3 3 DPG

D. HbF

HbF

30 - Oxygen dissociation curve shifts to the right by all of the following except_____________?

A. Rise in temperature

B. Rise in carbon dioxide tension

C. Rise in pH

D. Rise in H+ ion

Rise in pH

31 - Shift of the oxygen dissociation curve to right is caused by the following factors EXCEPT_______________?

A. Increased 2,3 BPG

B. Increased temperature

C. Increased concentration of carbon – di – oxide

D. Increased concentration of oxygen

Increased concentration of oxygen

32 - Smoking causes_____________?

A. Ciliary motility

B. Cellular hyperplasia

C. Mucous secretion

D. All of the above

All of the above

33 - Surfactant is secreted by_____________?

A. Pnemocyte I

B. Pnemocyte II

C. Goblet cells

D. Pulmonary vessels

Pnemocyte II

34 - The alveolar ventilation in an individual with tidal volume: 600 ml, dead space 150 ml and respiratory rate of 15/ minute is_____________?

A. 2.5 lit/Min

B. 4.0 lit /Min

C. 6.75 Lit/Min

D. 9 Lit/Min

6.75 Lit/Min

35 - The approximate amount of air left in the lungs after maximal forced expiration in a normal woman______________?

A. 0.5 L

B. 2.0 L

C. 1.1 L

D. 1.8 L

1.1 L

36 - The best stimulator of respiratory center is____________?

A. Decrease in arterial carbon dioxide level

B. Increase in arterial carbon dioxide level

C. Increase in arterial oxygen level

D. None of the above

Increase in arterial carbon dioxide level

37 - The intrapleural pressure at the end of deep inspiration is ______________?

A. -4 mm Hg

B. +4 mm Hg

C. -18 mm Hg

D. + mm Hg

-4 mm Hg

38 - The major sign of hypoventilations_____________?

A. Cyanosis

B. Dyspnea

C. Hypercapnia

D. Hypoxia

Hypercapnia

39 - The most common form of hypoxia is______________?

A. Hypoxic

B. Stagnant

C. Anemic

D. Histotoxic

Hypoxic

40 - The oxygen tension of the mixed venous blood is______________?

A. 25 mm Hg

B. 40 mm Hg

C. 55 mm Hg

D. 70 mm Hg

40 mm Hg

41 - The quantity of water lost in expired air each 24 hrs is about___________?

A. 200 ML

B. 400 ML

C. 600 ML

D. 800 ML

400 ML

42 - The transport of CO is diffusion limited because_______________?

A. Bind avidly with Hb

B. Partial pressure of CO is less

C. CO is less absorbed in water

D. Alveolar membrane is less permeable

Bind avidly with Hb

43 - The type of hypoxia present in high attitude is_____________?

A. Anemic Hypoxia

B. Hypoxic Hypoxia

C. Stagnant Hypoxia

D. Histotoxic Hypoxia

Hypoxic Hypoxia

44 - The volume of gas in the lungs at the end of normal expiration is____________?

A. Expiratory reserve volume

B. Functional residual capacity

C. Residual volume

D. Inspiratory reserve volume

Functional residual capacity

45 - The work of breathing__________________?

A. is inversely related to lung compliance

B. remains constant during exercise

C. is not affected by respiratory

D. decreased in lying posture

is inversely related to lung compliance

46 - tidal volume in adult is_____________?

A. 125 ml

B. 500 ml

C. 1500 ml

D. 2200 ml

500 ml

47 - Ventilation perfusion ratio is maximum in_______________?

A. Base of lung

B. Apex of lung

C. Posterior lobe of lung

D. Middle lobe of lung

Apex of lung

48 - Vital capacity is a measure of________________?

A. Tidal volume

B. Inspiratory reserve volume plus expiratory volume

C. Tidal volume plus inspiratory reserve volume plus expiratory reserve volume

D. Expiratory reserve volume plus reserve volume

Tidal volume plus inspiratory reserve volume plus expiratory reserve volume

49 - Vital capacity is decreased, timed vital capacity (FEV 1.0 %) is normal in______________?

A. Bronchial asthma

B. Scoliosis

C. Chronic bronchitis

D. Acute bronchitis

Scoliosis

50 - What effect does hyperventilation have on the oxygen binding affinity of hemoglobin ?

A. P50 and oxygen affinity decrease

B. P 50 and oxygen affinity increase

C. P 50 decreases and the oxygen affinity increases

D. P50 increase and the oxygen affinity decreases

P 50 and oxygen affinity increase

51 - What is true about pneumothorax ?

A. Total chest wall diameter is increased

B. Interpleural pressure becomes more negative

C. The concentration of surfactant is reduced in alveoli

D. Increased lung compliance

Total chest wall diameter is increased

52 - Which of the following adaptations will be apt to increase the work capacity at high altitude_________________?

A. Increased workload, decreasing duration of exercise

B. Increased workload, increasing duration of exercise

C. Decreasing workload, increasing duration of exercise

D. Decreasing workload, decreasing duration of exercise

Decreasing workload, increasing duration of exercise

53 - Which of the following does not stimulate alveolar hyperventilation ?