alleryStart learning →When does a full complement of functional alveoli appear?
AAt around eight years of age
BAt around eight months of age
CAt around the time of birth
DAt around week 36 of gestation
Answer & Solution
Correct answer: A. At around eight years of age
1. Enough alveoli exist by week 28 for a premature baby to breathe unaided.
2. That is not the same as having the full adult complement.
3. A full complement of functional alveoli does not appear until around 8 years of age.
4. So the lungs are not fully developed until early childhood, and the eight months option confuses the unit of time.
_Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 22 "The Respiratory System", section 22.7 Embryonic Development of the Respiratory System_
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