Consider the following statements regarding the pathway of air in the human respiratory system:
I. External nostrils open out above the upper lips and lead to the nasal chamber through the nasal passage. II. The nasal chamber opens into the pharynx, which is a common passage for food and air. III. The pharynx opens through the larynx region into the trachea. IV. The larynx opens directly into the primary bronchi without passing through the trachea.
Statements I, II, and III are correct: Air passes from external nostrils → nasal passage → nasal chamber → pharynx → larynx → trachea. Statement IV is incorrect because the larynx opens into the trachea, which subsequently branches into primary bronchi.
Question 12 of 100
📘 CLASS XI
Analyze the following statements regarding the larynx and epiglottis:
I. Larynx is a cartilaginous box which helps in sound production and is called the sound box. II. During swallowing, glottis can be covered by a thin elastic cartilaginous flap called epiglottis. III. The primary function of epiglottis is to prevent the entry of food into the larynx. IV. The epiglottis is a bony structure present at the division of the trachea.
Statements I, II, and III are correct: The larynx is a cartilaginous sound box, and the epiglottis is a thin elastic cartilaginous flap covering the glottis during swallowing to prevent food entry into the larynx. Statement IV is incorrect because epiglottis is elastic cartilage covering the glottis, not a bony structure at tracheal bifurcation.
Question 13 of 100
📘 CLASS XI
Regarding the anatomical branching of the human trachea, consider the following statements:
I. Trachea is a straight tube extending up to the mid-thoracic cavity. II. Trachea divides at the level of the 5th thoracic vertebra into right and left primary bronchi. III. Each primary bronchus undergoes repeated divisions to form secondary and tertiary bronchi and bronchioles. IV. Terminal bronchioles give rise to thick, non-vascularised rigid sacs called alveoli.
Statements I, II, and III are correct: The trachea extends to the mid-thoracic cavity, divides at the 5th thoracic vertebra into primary bronchi, which branch into secondary/tertiary bronchi and bronchioles. Statement IV is incorrect because alveoli are very thin, irregular-walled, and highly vascularised bag-like structures.
Question 14 of 100
📘 CLASS XI
Which of the following structures in the human respiratory tract are supported by incomplete cartilaginous rings?
I. Trachea II. Primary, secondary, and tertiary bronchi III. Initial bronchioles IV. Alveoli and alveolar ducts
Statements I, II, and III are correct: Incomplete cartilaginous rings support the trachea, primary, secondary, and tertiary bronchi, and initial bronchioles. Statement IV is incorrect because terminal bronchioles, alveoli, and alveolar ducts lack cartilaginous rings.
Question 15 of 100
📘 CLASS XI
Consider the following statements regarding human alveoli:
I. Alveoli are very thin, irregular-walled, and vascularised bag-like structures. II. Each terminal bronchiole gives rise to a number of alveoli. III. Alveoli and their ducts constitute the respiratory or exchange part of the respiratory system. IV. Alveoli are supported by complete cartilaginous rings to prevent collapse.
Statements I, II, and III are correct: Terminal bronchioles give rise to thin, irregular-walled, vascularised bag-like alveoli which form the exchange part. Statement IV is incorrect because alveoli do not have cartilaginous rings.
Question 16 of 100
📘 CLASS XI
Analyze the following statements about the lungs and pleural membranes:
I. We have two lungs covered by a double layered pleura. II. Pleural fluid between the pleural membranes reduces friction on the lung surface. III. Outer pleural membrane is in close contact with the thoracic lining. IV. Inner pleural membrane is in contact with the lung surface.
All four statements (I, II, III, and IV) are correct: Lungs are covered by double-layered pleura with pleural fluid between them; the outer membrane contacts the thoracic lining and the inner membrane contacts the lung surface.
Question 17 of 100
📘 CLASS XI
Consider the anatomical boundaries forming the human thoracic chamber:
I. Dorsally formed by the vertebral column. II. Ventrally formed by the sternum. III. Laterally formed by the ribs. IV. On the lower side formed by the dome-shaped diaphragm.
All four statements are correct: The thoracic chamber is bounded dorsally by the vertebral column, ventrally by the sternum, laterally by the ribs, and inferiorly by the dome-shaped diaphragm.
Question 18 of 100
📘 CLASS XI
Regarding the anatomical setup of lungs in the thoracic cavity, analyze the statements:
I. The thoracic cavity is anatomically an air-tight chamber. II. Any change in the volume of the thoracic cavity will be reflected in the lung (pulmonary) cavity. III. We can directly alter the pulmonary volume without changing thoracic volume. IV. The air-tight setup is essential for breathing mechanisms.
Statements I, II, and IV are correct: The thoracic chamber is air-tight, so changes in thoracic volume reflect in pulmonary volume, which is essential because we cannot directly alter pulmonary volume. Statement III is incorrect because we cannot directly alter pulmonary volume.
Question 19 of 100
📘 CLASS XI
Examine the following statements regarding the conducting part of the respiratory system:
I. It extends from external nostrils up to the terminal bronchioles. II. It transports atmospheric air to the alveoli. III. It clears air from foreign particles, humidifies it, and brings it to body temperature. IV. It is the site of actual diffusion of O2 and CO2 between blood and atmospheric air.
Statements I, II, and III are correct: The conducting part spans external nostrils to terminal bronchioles, transporting, clearing, humidifying, and temperature-adjusting air. Statement IV is incorrect because actual diffusion occurs at the exchange part (alveoli and their ducts).
Question 20 of 100
📘 CLASS XI
Consider the following statements regarding the exchange (respiratory) part of the respiratory system:
I. It consists of the alveoli and their ducts. II. It is the site of actual diffusion of O2 and CO2 between blood and atmospheric air. III. It humidifies atmospheric air and brings it to body temperature. IV. It includes trachea, primary bronchi, and initial bronchioles.
Statements I and II are correct: Alveoli and their ducts form the exchange part where actual diffusion of O2 and CO2 occurs. Statements III and IV are incorrect because humidifying/clearing air and structures like trachea/bronchi belong to the conducting part.
