The structures with a diameter less than 1mm are:
Correct answer: A. Bronchioles
- A. Bronchioles
- B. Bronchi
- C. Alveoli
- D. Air sac
Explanation
Bronchioles are approximately 1 mm or less in diameter and their walls consist of ciliated cuboidal epithelium and a layer of smooth muscle (the bronchioles carry air to small sacs in your lungs called alveoli )
Last updated
About Respiration
The human respiratory system includes the air passages, lungs, alveoli and breathing muscles, while gaseous exchange explains how oxygen enters blood and carbon dioxide leaves it by diffusion. The effects of smoking include damage to cilia and alveoli, reduced gas exchange, chronic bronchitis, emphysema and increased risk of lung cancer.
Practise Respiration
446 free Respiration MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A cavity bounded by the ribs and diaphragm is called:
A disease caused by gradual breakdown of the thin walls of alveoli is:
A large proportion of oxygen remains unused in the human blood even after its uptake by the body tissues. This O2 _.
A large proportion of oxygen remains unused in the human blood even after its uptake by the body tissues. This O2 _.
A surfactant is essential for: