Respiratory Tract Structure & Function — NEET Biology
📚 Practice ConceptWe have a pair of external nostrils opening out above the upper lips. It leads to a nasal chamber through the nasal passage. The nasal chamber opens into the pharynx, a portion of which is the common passage for food and air. The pharynx opens through the larynx region into the trachea. Larynx is a cartilaginous box which helps in sound production and hence called the sound box. During swallowing glottis can be covered by a thin elastic cartilaginous flap called epiglottis to prevent the entry of food into the larynx. Trachea is a straight tube extending up to the mid-thoracic cavity, which divides at the level of 5th thoracic vertebra into a right and left primary bronchi. Each bronchi undergoes repeated divisions to form the secondary and tertiary bronchi and bronchioles ending up in very thin terminal bronchioles. The tracheae, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings. Each terminal bronchiole gives rise to a number of very thin, irregular-walled and vascularised bag-like structures called alveoli. The branching network of bronchi, bronchioles and alveoli comprise the lungs. We have two lungs which are covered by a double layered pleura, with pleural fluid between them. It reduces friction on the lung-surface. The outer pleural membrane is in close contact with the thoracic
Which of the above statements are NOT correct? S1: The larynx is a cartilaginous box, often referred to as the sound box, due to its role in sound production. S2: The pharynx serves as a common passage for food and air, opening into the larynx region which then leads to the trachea. S3: The glottis, the opening into the larynx, is covered by a thin elastic cartilaginous flap called the epiglottis during breathing to prevent food entry. S4: The trachea, primary bronchi, and initial bronchioles are supported by complete cartilaginous rings to prevent their collapse. S5: The respiratory or exchange part of the human respiratory system is responsible for transporting atmospheric air to the alveoli, clearing it from foreign particles, humidifying it, and bringing it to body temperature.
View solution & NCERT explanation
Correct answer: B — S3, S4 and S5
The question asks to identify the statements that are NOT correct regarding the human respiratory system. S1: "The larynx is a cartilaginous box, often referred to as the sound box, due to its role in sound production." This statement is **correct**. According to NCERT, "Larynx is a cartilaginous box which helps in sound production and hence called the sound box." S2: "The pharynx serves as a common passage for food and air, opening into the larynx region which then leads to the trachea." This statement is **correct**. The NCERT states that the pharynx is "a portion of which is the common passage for food and air. The pharynx opens through the larynx region into the trachea." S3: "The glottis, the opening into the larynx, is covered by a thin elastic cartilaginous flap called the epiglottis during breathing to prevent food entry." This statement is **incorrect**. The epiglottis covers the glottis specifically *during swallowing* to prevent the entry of food into the larynx, not during breathing. S4: "The trachea, primary bronchi, and initial bronchioles are supported by complete cartilaginous rings to prevent their collapse." This statement is **incorrect**. The NCERT specifies that these structures "are supported by incomplete cartilaginous rings." S5: "The respiratory or exchange part of the human respiratory system is responsible for transporting atmospheric air to the alveoli, clearing it from foreign particles, humidifying it, and bringing it to body temperature." This statement is **incorrect**. These functions (transporting air, clearing foreign particles, humidifying, and bringing air to body temperature) are attributed to the *conducting part* of the respiratory system. The *exchange part* (alveoli and their ducts) is the site of actual diffusion of gases. Therefore, statements S3, S4, and S5 are not correct. The core concept tested here is the detailed anatomy and specific functions of various parts of the human respiratory system, particularly the larynx, trachea, and the distinction between the conducting and exchange parts.
What does NCERT say about We have pair external?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.