NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Biology
- Chapter
- Chapter
NEET 2026 · Biology · Chapter
The human respiratory system is functionally divided into a...
The human respiratory system is functionally divided into a conducting part and a respiratory (exchange) part. Which of the following correctly identifies the structures forming the exchange part and their primary function?
Options
- AExternal nostrils to terminal bronchioles; humidifies and warms the inhaled air
- BAlveoli and their ducts; site of actual diffusion of and between blood and atmospheric air
- CTrachea, bronchi, and initial bronchioles; clears inhaled air from foreign particles
- DTerminal bronchioles and alveoli; brings the temperature of inhaled air to body temperature
Correct answer
B. Alveoli and their ducts; site of actual diffusion of and between blood and atmospheric air
Step-by-step solution
The human respiratory system consists of a conducting part and a respiratory or exchange part.
The conducting part starts from the external nostrils up to the terminal bronchioles. Its functions include transporting atmospheric air to the alveoli, clearing it from foreign particles, humidifying the air, and bringing it to body temperature.
The exchange part comprises the alveoli and their ducts. Its primary function is to serve as the site of actual diffusion of and between the blood and atmospheric air.
Answer: Alveoli and their ducts; site of actual diffusion of and between blood and atmospheric air
The conducting part starts from the external nostrils up to the terminal bronchioles. Its functions include transporting atmospheric air to the alveoli, clearing it from foreign particles, humidifying the air, and bringing it to body temperature.
The exchange part comprises the alveoli and their ducts. Its primary function is to serve as the site of actual diffusion of and between the blood and atmospheric air.
Answer: Alveoli and their ducts; site of actual diffusion of and between blood and atmospheric air