'If these air sacs were flattened out, the lungs would have a surface area of up to 1,000 square feet'
the alveoli
THE HUMAN BODY: If these air sacs were flattened out, the lungs would have a surface area of up to 1,000 square feet
If these air sacs were flattened out, the lungs would have a surface area of up to 1,000 square feet
If these air sacs were flattened out, the lungs would have a surface area of up to 1,000 square feet
THE HUMAN BODY
the alveoli
THE HUMAN BODY