Question 1

The process of breathing in oxygen is called–?

Accepted Answer

Answer reason: Inhalation is the active phase of ventilation in which the diaphragm contracts and the thoracic cavity expands, drawing oxygen-rich air into the lungs. Exhalation is the opposite process, expelling carbon dioxide. Circulation refers to blood flow, not air movement. Respiration is a broader term for overall gas exchange and cellular metabolism rather than the specific act of breathing in.

Question 2

The covering of the lungs is called?

Accepted Answer

Answer reason: The lungs are covered by the visceral pleura, a serous membrane; the parietal pleura lines the thoracic cavity, forming a pleural cavity that reduces friction during breathing. The peritoneum lines the abdominal cavity, not the lungs. The pericardium surrounds the heart, and the myocardium is the muscular layer of the heart. Therefore, the covering of the lungs is the pleura.

Question 3

The tiny air sacs in the lungs are called?

Accepted Answer

Answer reason: Alveoli are microscopic air sacs at the end of the respiratory bronchioles where gas exchange occurs across the alveolar-capillary membrane. Bronchi are larger conducting airways that do not participate in gas exchange. The pleura is the serous membrane surrounding the lungs, and capillaries are small blood vessels that surround the alveoli to facilitate diffusion.

Question 4

Which gas is removed from the lungs during respiration?

Accepted Answer

Answer reason: During external respiration, carbon dioxide diffuses from venous blood into the alveoli due to its higher partial pressure in blood. It is then expelled during exhalation. Oxygen moves in the opposite direction, while nitrogen and helium are largely inert and not exchanged. Therefore, carbon dioxide is the gas removed from the lungs.

Question 5

Humans have ___ Lobes in the Right lung?

Accepted Answer

Answer reason: The right lung is composed of three lobes—superior, middle, and inferior—separated by the horizontal and oblique fissures. In contrast, the left lung has only two lobes because space is occupied by the heart (cardiac notch). Therefore, the correct number of lobes in the right lung is three.

Question 6

The process of taking air into the lungs is called?

Accepted Answer

Answer reason: Inhalation is the phase of ventilation in which air is drawn into the lungs as the diaphragm contracts and thoracic volume increases, creating negative intrathoracic pressure. Exhalation is the opposite process of moving air out. Digestion and filtration are unrelated physiological processes.

Question 7

The opening of the trachea into the lungs is called?

Accepted Answer

Answer reason: The trachea bifurcates at the carina into the right and left main bronchi, which enter the lungs. Alveoli are distal air sacs where gas exchange occurs, not the airway opening from the trachea. The pleura are serous membranes surrounding the lungs, and capillaries are blood vessels. Therefore, the correct term for the tracheal openings into the lungs is the bronchi.

Question 8

Normal respiratory rate and rhythm is termed as ...?

Accepted Answer

Answer reason: Eupnea refers to normal, unlabored breathing with a regular rate and rhythm. Apnea is the absence of breathing. Tachycardia and bradycardia describe abnormal heart rates, not respiratory patterns. Therefore, the correct term for normal respirations is eupnea.

Question 9

Function of lungs is _______?

Accepted Answer

Answer reason: The lungs’ primary physiologic role is gas exchange, where oxygen diffuses from alveoli into pulmonary capillaries and carbon dioxide diffuses from blood into alveoli for exhalation. This occurs across the thin alveolar–capillary membrane driven by partial-pressure gradients. Absorption and digestion are functions of the gastrointestinal system, not the lungs, and therefore 'None of them' is incorrect.

Question 10

Gas exchange takes place in the?

Accepted Answer

Answer reason: Gas exchange occurs across the thin respiratory membrane in the alveoli, where type I pneumocytes interface with pulmonary capillaries. Oxygen diffuses from alveolar air into the blood while carbon dioxide diffuses from blood into the alveolar space. The larynx and bronchioles are primarily conducting airways and do not perform gas exchange. The pleura are serous membranes that facilitate lung movement, not diffusion of gases.

Question 11

The diaphragm help in the ...?

Accepted Answer

Answer reason: The diaphragm is the primary muscle of inspiration. When it contracts, it flattens and increases thoracic volume, creating negative intrathoracic pressure that draws air into the lungs; relaxation aids passive expiration. Excretion refers to renal elimination of wastes, and digestion involves gastrointestinal processes, neither of which is the diaphragm’s primary function.

Question 12

Pulmonary vascular resistance is increased by the following?

Accepted Answer

Answer reason: Alveolar hypoxia triggers hypoxic pulmonary vasoconstriction, redirecting blood flow away from poorly ventilated regions and thereby increasing pulmonary vascular resistance. Hypocapnia tends to dilate pulmonary vessels and reduce PVR (hypercapnia would increase it). Acidosis has variable effects but is less consistent without concurrent hypoxia. Epinephrine generally lowers PVR via beta-2–mediated vasodilation in the pulmonary circulation.

Question 13

The survival of preterm baby is mainly dependent on maturity of?

Accepted Answer

Answer reason: Preterm infant survival is most strongly tied to pulmonary maturity because inadequate surfactant leads to respiratory distress syndrome with alveolar collapse and severe hypoxemia. An adequate L/S ratio and surfactant production are key for effective gas exchange after birth. While other organs are immature, the lungs are the critical determinant of immediate postnatal viability.

Question 14

Main organ of respiration is?

Accepted Answer

Answer reason: The lungs are the primary organs of respiration where gas exchange occurs. Oxygen diffuses across the alveolar-capillary membrane into the blood while carbon dioxide diffuses out for exhalation. The heart circulates blood but does not perform gas exchange, and the kidney and liver have excretory and metabolic functions, respectively.

Question 15

Disease in which destruction of walls of Alveli is found?

Accepted Answer

Answer reason: Emphysema is characterized by permanent enlargement of airspaces distal to the terminal bronchioles with destruction of alveolar walls, leading to loss of elastic recoil and reduced gas-exchange surface area. Asthma primarily involves reversible airway inflammation and bronchoconstriction rather than alveolar wall destruction. Pneumonia causes alveolar exudates and consolidation, and bronchitis involves inflammation of the bronchi with mucus hypersecretion, not destruction of alveolar septa.

Question 16

Place where trachea bifurcates into right and left bronchus is ________?

Accepted Answer

Answer reason: The trachea divides into the right and left main bronchi at the carina, a ridge of cartilage at the inferior end of the trachea (around the level of T4–T5/sternal angle). This is a key anatomic landmark in bronchoscopy and airway assessment because it is highly sensitive and can trigger coughing. The other options are either the tube itself (trachea), the branches after division (bronchi), or the lung root entry area (hilus), not the bifurcation point.

Question 17

Most common cause for lung cancer is ...?

Accepted Answer

Answer reason: Cigarette smoking is the leading cause of lung cancer, responsible for the majority of cases through chronic exposure to tobacco carcinogens (e.g., polycyclic aromatic hydrocarbons and nitrosamines). These agents cause DNA damage and mutations in airway epithelial cells over time, increasing risk in a dose-dependent manner (pack-years). Alcohol is not a primary causal factor for lung cancer, and tuberculosis may cause lung scarring but is not the most common cause compared with tobacco exposure.

Question 18

Where does gas exchange occur in the lungs?

Accepted Answer

Answer reason: Gas exchange occurs across the thin alveolar-capillary membrane in the alveoli, where oxygen diffuses into pulmonary capillaries and carbon dioxide diffuses into the alveolar air to be exhaled. The bronchi, bronchioles, and trachea are conducting airways that primarily move air and condition it (warming, humidifying, filtering) rather than exchanging gases. The alveoli provide the large surface area and close capillary network needed for efficient diffusion.

Question 19

The common respiratory problem in preterm babies is due to deficiency of?

Accepted Answer

Answer reason: Preterm infants commonly develop neonatal respiratory distress syndrome because type II pneumocytes are immature and produce insufficient pulmonary surfactant. Low surfactant increases alveolar surface tension, causing alveolar collapse (atelectasis), decreased lung compliance, and impaired gas exchange. This is why exogenous surfactant and respiratory support are key treatments in premature neonates.

Question 20

Lungs capacity of human body is?

Accepted Answer

Answer reason: The question is asking for the approximate total lung capacity (TLC) in an average adult. TLC is typically around 6 liters (about 6,000 mL), though it varies with sex, height, and age. Among the options, 6 liters best matches the commonly taught physiologic value for normal adult TLC.

Question 21

Where does gas exchange occur in the lungs?

Accepted Answer

Answer reason: Gas exchange occurs across the thin alveolar-capillary membrane in the alveoli, where oxygen diffuses into pulmonary capillary blood and carbon dioxide diffuses out to be exhaled. The trachea and bronchi primarily conduct air and do not have the thin, capillary-rich surfaces needed for diffusion. The pleura is a protective lining around the lungs and is not involved in gas exchange.

Question 22

The first cry of baby helps in?

Accepted Answer

Answer reason: A newborn’s first cry generates negative intrathoracic pressure that helps expand the alveoli and establish effective ventilation. This aeration promotes clearance of fetal lung fluid and reduces pulmonary vascular resistance, enabling the transition to normal postnatal circulation. Therefore, the first cry primarily helps with opening and inflating the lungs rather than digestion, kidney function, or directly initiating heartbeat.

Question 23

FiO2 normal air?

Accepted Answer

Answer reason: FiO2 is the fraction of inspired oxygen. Room (ambient) air contains approximately 21% oxygen, which corresponds to an FiO2 of 0.21. Higher percentages (40%, 60%, 100%) represent supplemental oxygen delivery rather than normal air.

Question 24

Dyspnea is defined as ...?

Accepted Answer

Answer reason: Dyspnea means subjective difficulty or discomfort in breathing (shortness of breath), which corresponds best to “difficult respiration.” “Absence of breathing” defines apnea, not dyspnea. Cyanosis and pallor are physical signs that may accompany hypoxemia or poor perfusion but are not the definition of dyspnea.

Question 25

Cyanosis is caused in case of ...?

Accepted Answer

Answer reason: Cyanosis is a bluish discoloration of skin and mucous membranes caused by increased deoxygenated hemoglobin, typically from inadequate oxygenation of arterial blood. Therefore, the primary cause is lack of oxygen (hypoxemia) or impaired oxygen delivery leading to increased reduced hemoglobin. Dehydration (lack of water) and hypoglycemia (lack of glucose) do not directly cause cyanosis, and anemia (lack of blood/hemoglobin) more often causes pallor and may mask cyanosis rather than produce it.

Question 26

Decrease oxygen tension in blood is due to which of the following?

Accepted Answer

Answer reason: Oxygen tension refers to the partial pressure of dissolved oxygen in arterial blood (PaO2), which is primarily determined by alveolar ventilation and gas exchange. Hypoventilation raises PaCO2 and lowers alveolar oxygen (PAO2), leading to decreased PaO2 (oxygen tension). In anemia and CO poisoning, PaO2 is typically normal because dissolved oxygen is unchanged; instead, oxygen content and delivery are reduced due to decreased effective hemoglobin binding/carrying capacity. Polycythemia increases oxygen-carrying capacity and does not by itself lower PaO2.

Question 27

Which part of the human body is affected by bronchitis?

Accepted Answer

Answer reason: Bronchitis is inflammation of the bronchi (bronchial tubes), which are conducting airways within the respiratory tract. This inflammation causes cough and mucus production due to irritation and swelling of the airway lining. Because the primary site of disease is the bronchi/airways, the affected body system is the respiratory tract rather than blood, liver, or brain.

Question 28

Fluids in the lungs is called?

Accepted Answer

Answer reason: Among the options, pneumonia best matches the idea of “fluid in the lungs” because it involves inflammation and infection of the alveoli leading to filling with exudate (fluid/pus), producing consolidation on imaging. Emphysema is destruction of alveolar walls with air trapping, not fluid accumulation. Asthma and bronchitis primarily involve airway inflammation/bronchospasm and mucus, rather than alveolar fluid filling. Therefore, pneumonia is the single best answer from the provided choices.

Question 29

Which organ allows the body to exchange oxygen and carbon dioxide?

Accepted Answer

Answer reason: The lungs are the primary organs responsible for gas exchange, where oxygen diffuses into the blood and carbon dioxide diffuses out across the alveolar-capillary membrane. This exchange occurs in the alveoli, which provide a large surface area and thin barrier for diffusion. The heart primarily pumps blood, and the kidneys regulate fluid/electrolytes and acid-base balance rather than performing direct oxygen–carbon dioxide exchange.

Question 30

The tiny air sacs in lungs are called?

Accepted Answer

Answer reason: Alveoli are the microscopic air sacs at the ends of the respiratory bronchioles where gas exchange occurs across the alveolar-capillary membrane. Oxygen diffuses into pulmonary capillaries and carbon dioxide diffuses into the alveolar space for exhalation. Nephrons are kidney functional units, villi are intestinal absorptive projections, and bronchioles are small airways that conduct air but are not the primary gas-exchange sacs.

Question 31

Inspiratory air in lungs ultimately reaches?

Accepted Answer

Answer reason: Inspired air passes through the conducting airways (trachea → bronchi → bronchioles) and ultimately reaches the alveoli. The alveoli are the terminal air sacs where gas exchange with pulmonary capillary blood occurs. Trachea, bronchi, and bronchioles primarily conduct air and do not serve as the main site of gas exchange.

Question 32

Site of gaseous exchange in lungs is ...?

Accepted Answer

Answer reason: Gas exchange occurs across the thin alveolar-capillary (respiratory) membrane in the alveoli, where oxygen diffuses into pulmonary capillaries and carbon dioxide diffuses into the alveolar air. Bronchioles and tracheoles primarily conduct air and do not have the extensive thin-walled surface area required for efficient diffusion. The pulmonary vein transports oxygenated blood away from the lungs but is not the site of diffusion itself.

Question 33

The most common neonatal cause of death in preterm baby is?

Accepted Answer

Answer reason: In preterm neonates, respiratory distress syndrome (RDS) is a leading cause of early neonatal mortality due to surfactant deficiency and resultant alveolar collapse, hypoxemia, and respiratory failure. The risk rises as gestational age decreases because surfactant production is inadequate before late gestation. While sepsis and congenital anomalies also contribute significantly, RDS is classically the most common early neonatal cause of death specific to prematurity. Jaundice is common but rarely a primary cause of death when managed.

Question 34

What is the normal percentage of oxygen in the air we breathe?

Accepted Answer

Answer reason: Room air contains approximately 21% oxygen (FiO2 0.21) at sea level. The remaining major components are nitrogen (~78%) and argon/other gases with a small amount of carbon dioxide. Therefore, 21% is the normal oxygen concentration in the air we breathe.

Question 35

Which of the following is an early sign of hypoxia?

Accepted Answer

Answer reason: Early hypoxia commonly presents with neurobehavioral changes such as restlessness, anxiety, irritability, and confusion due to reduced cerebral oxygenation. Cyanosis is a late sign because it requires significant desaturation and may be absent in anemia or poor perfusion. Bradycardia is generally a late and ominous sign of worsening hypoxia (especially in children), whereas early hypoxia more often causes tachycardia. Decreased urine output reflects reduced renal perfusion and is also a later, nonspecific manifestation rather than an early indicator of hypoxia.

Question 36

Which disease can cause hemoptysis?

Accepted Answer

Answer reason: Hemoptysis is coughing up blood originating from the lower respiratory tract, most commonly due to airway or lung parenchymal pathology. Lung cancer can erode bronchial mucosa and invade blood vessels, leading to blood in sputum. The other options are not causes of coughing blood: urinary infection causes hematuria, stomach cancer causes hematemesis or melena, and piles cause rectal bleeding.

Question 37

The Study of Lungs is called?

Accepted Answer

Answer reason: Pulmonology is the medical specialty focused on the lungs and the respiratory tract, including diagnosis and management of respiratory diseases. Nephrology and the term renal both relate to the kidneys, not the lungs. Therefore, the correct term for the study of lungs is pulmonology.

Question 38

Cyanosis occurs due to lack of?

Accepted Answer

Answer reason: Cyanosis is a bluish discoloration of skin and mucous membranes caused by increased deoxygenated hemoglobin in capillary blood, most commonly due to inadequate oxygenation (hypoxemia). When oxygen levels are low, more hemoglobin remains in the reduced (deoxygenated) form, producing the blue color. Platelets and water do not cause cyanosis, and low hemoglobin (anemia) typically makes cyanosis less apparent rather than causing it.

Question 39

At what fraction of inspired oxygen (FiO₂) level does the risk of oxygen toxicity significantly increase when administered for a prolonged period?

Accepted Answer

Answer reason: Prolonged exposure to high inspired oxygen concentrations increases reactive oxygen species generation, causing pulmonary epithelial injury and absorption atelectasis. Clinically, risk of oxygen toxicity is commonly emphasized when FiO2 is maintained above about 0.60 for extended periods, prompting efforts to titrate to the lowest FiO2 that maintains adequate oxygenation. Lower thresholds (30–40%) are not typically considered toxic, while 90% is unnecessarily high and not the usual teaching cutoff.

Question 40

What is the normal respiratory rate for an adult?

Accepted Answer

Answer reason: Normal adult respiratory rate at rest is typically 12–20 breaths per minute. Rates below 12 suggest bradypnea and rates above 20 suggest tachypnea, depending on context. Among the choices, 12–20 bpm best matches the accepted normal reference range for adults.

Question 41

The term "hypoxia" refers to?

Accepted Answer

Answer reason: Hypoxia refers to inadequate oxygen available to tissues, commonly reflected clinically as low oxygenation (e.g., decreased PaO2/SpO2). Among the choices, the best match is decreased oxygen levels, whereas increased carbon dioxide describes hypercapnia and decreased carbon dioxide describes hypocapnia. Option A is the opposite of hypoxia.

Question 42

Which oxygen device delivers the highest concentration?

Accepted Answer

Answer reason: A non-rebreather mask can deliver the highest FiO2 among the listed devices because it uses a reservoir bag and one-way valves to minimize entrainment of room air and prevent re-inhalation of exhaled gases. When the mask fits well and oxygen flow is sufficient to keep the reservoir inflated, it can provide very high oxygen concentrations (often up to ~60–90% or higher in ideal conditions). Venturi masks provide precise but typically lower fixed FiO2, and nasal cannula/simple masks deliver lower, more variable FiO2 due to room-air mixing. Therefore, the non-rebreather mask is the best answer.

Question 43

Allergen causes –?

Accepted Answer

Answer reason: Allergens commonly trigger a type I hypersensitivity reaction in the airways, leading to bronchial hyperresponsiveness, inflammation, and reversible bronchoconstriction—hallmarks of asthma. Bronchitis and pneumonia are typically infectious or irritant-related inflammatory conditions rather than primarily allergen-driven. Bronchiectasis is a chronic structural airway dilation most often due to recurrent infections or conditions like cystic fibrosis, not acute allergen exposure.

Question 44

The most common cause of death in children under five years globally is?

Accepted Answer

Answer reason: Globally, pneumonia is the leading infectious cause of mortality in children under 5 years and is commonly cited as the most frequent single cause of under-five deaths. While diarrhea and malaria are also major contributors in many regions, their overall global mortality burden in under-fives is typically lower than pneumonia. Malnutrition is a critical underlying risk factor that increases susceptibility and severity of infections, but it is not usually classified as the single most common direct cause of death in this age group.

Question 45

A normal oxygen saturation level (SpO2) is?

Accepted Answer

Answer reason: In healthy adults at sea level, pulse oximetry (SpO2) is typically in the mid-to-high 90s, and commonly cited as 95–100%. Values in the 70–80% or 60–75% ranges indicate severe hypoxemia and are not normal. An SpO2 of 85–90% is below normal and usually prompts assessment and intervention depending on the clinical context.

Question 46

Normal RR in ventilator adults?

Accepted Answer

Answer reason: In mechanically ventilated adults, the typical set/target respiratory rate generally mirrors normal adult resting physiology, commonly around 12–16 breaths per minute. Rates lower than this (e.g., 6–8) risk hypoventilation unless paired with very large tidal volumes, while higher rates (20–30) are used in specific clinical situations and can increase risk of air trapping and respiratory alkalosis. Therefore, 12–16 is the best answer among the options provided.

Question 47

What is the major organ of Respiratory system?

Accepted Answer

Answer reason: The lungs are the primary organs of the respiratory system and are responsible for gas exchange (oxygen uptake and carbon dioxide elimination) at the alveoli. The heart is the main organ of the cardiovascular system, pumping blood to and from the lungs and body. The liver is part of the gastrointestinal/hepatobiliary system and is not a respiratory organ.

Question 48

Full support ventilation mode?

Accepted Answer

Answer reason: Assist-control (AC) is considered a full-support ventilation mode because the ventilator delivers a set tidal volume (or pressure) for mandatory breaths and also provides full ventilator-supported breaths when the patient triggers additional breaths. In contrast, SIMV allows spontaneous breaths between mandatory breaths and is typically partial support. PSV provides pressure assistance only for spontaneous breaths (not full support), and CPAP provides continuous positive airway pressure without providing mandatory ventilator breaths.

Question 49

Protective membrane around lungs is called ...?

Accepted Answer

Answer reason: The lungs are covered by the pleura, a double-layered serous membrane consisting of the visceral pleura (covering the lung surface) and the parietal pleura (lining the thoracic cavity). Between these layers is pleural fluid, which reduces friction during breathing and helps maintain lung expansion via surface tension/negative pressure. "Neural membrane" relates to nervous system coverings, and the aleurone layer is a plant seed structure, making them incorrect. Therefore, the protective membrane around the lungs is the pleural membrane.

Question 50

What is the most common symptom of pulmonary TB?

Accepted Answer

Answer reason: The hallmark and most common symptom of pulmonary tuberculosis is a persistent cough, classically lasting longer than 2–3 weeks. Pulmonary involvement causes chronic airway irritation and sputum production, sometimes with hemoptysis, along with systemic symptoms such as fever, night sweats, and weight loss. Abdominal pain and skin rash are not typical primary symptoms of pulmonary TB, and headache would suggest possible CNS involvement rather than uncomplicated pulmonary disease. Therefore, a cough for more than 2 weeks is the best answer.

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The process of breathing in oxygen is called–?

The covering of the lungs is called?

The tiny air sacs in the lungs are called?

Which gas is removed from the lungs during respiration?

Humans have ___ Lobes in the Right lung?

The process of taking air into the lungs is called?

The opening of the trachea into the lungs is called?

Normal respiratory rate and rhythm is termed as ...?

Function of lungs is _______?

Gas exchange takes place in the?

The diaphragm help in the ...?

Pulmonary vascular resistance is increased by the following?

The survival of preterm baby is mainly dependent on maturity of?

Main organ of respiration is?

Disease in which destruction of walls of Alveli is found?

Place where trachea bifurcates into right and left bronchus is ________?

Most common cause for lung cancer is ...?

Where does gas exchange occur in the lungs?

The common respiratory problem in preterm babies is due to deficiency of?

Lungs capacity of human body is?

Where does gas exchange occur in the lungs?

The first cry of baby helps in?

FiO2 normal air?

Dyspnea is defined as ...?

Cyanosis is caused in case of ...?

Decrease oxygen tension in blood is due to which of the following?

Which part of the human body is affected by bronchitis?

Fluids in the lungs is called?

Which organ allows the body to exchange oxygen and carbon dioxide?

The tiny air sacs in lungs are called?

Inspiratory air in lungs ultimately reaches?

Site of gaseous exchange in lungs is ...?

The most common neonatal cause of death in preterm baby is?

What is the normal percentage of oxygen in the air we breathe?

Which of the following is an early sign of hypoxia?

Which disease can cause hemoptysis?

The Study of Lungs is called?

Cyanosis occurs due to lack of?

At what fraction of inspired oxygen (FiO₂) level does the risk of oxygen toxicity significantly increase when administered for a prolonged period?

What is the normal respiratory rate for an adult?

The term "hypoxia" refers to?

Which oxygen device delivers the highest concentration?

Allergen causes –?

The most common cause of death in children under five years globally is?

A normal oxygen saturation level (SpO2) is?

Normal RR in ventilator adults?

What is the major organ of Respiratory system?

Full support ventilation mode?

Protective membrane around lungs is called ...?

What is the most common symptom of pulmonary TB?

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