The Alveoli and Exchange of gases in the lungs

Question 1

What are the alveoli?
What are the walls lined up with?

What is each alveolus surrounded with?

Answer 1

The site of gas exchange in mammals

lined with epithelial cells

a network of pulmonary
capillaries

Question 2

What is alveolous?

What is it covered with on the outside?

What is the advantage of the epithelia lining inside of the alveolus?

Answer 2

a bundle of air sacs(alveoli)

tiny blood vessels.

The moist lining also stops the alveolus from drying and cracking. It lubricates the insides of the air
bag.

Question 3

What are the adaptations of the alveoli?

Answer 3

1- Large surface area to volume ratio:
speeds up the rate of exchange

2- Thin exchange surfaces:
short diffusion pathway

3- Partially permeable:
to allow selected materials to diffuse
easily

4- A steep concentration gradient :
maintained by breathing and blood flow