Question

12. Which of these statements is correct about alveoli?
(A) They form a very large surface area.
(B) They bave very thin walls.
C. they are covered with blood capillaries. D.All of these​

Answer 1

Correct answer is Option D

Explanation:

• Trachea is divides into primary bronchiole which is divided into secondary bronchiole , secondary bronchiole divided into tertiary bronchiole which is divided into initial bronchiole and then into terminal bronchiole. each terminal bronchiole give rise to a number of alveoli.
• This continuous branching process increase surface area. So, the alveoli form a large surface area for efficient gaseous exchange.
• The exchange of O2 and Co2 between the air space in the alveoli and blood within the pulmonary capillaries that surround the alveoli takes place by diffusion process through alveolar wall and capillary wall.
• for efficient gaseous exchange alveoli should have vey thin wall.
• so, all statements are correct

Answer 2

Answer:

answer is D all of the above