Alveoli Flashcards
What are alveoli
The alveoli are tiny air sacs, which are the main gas exchange surfaces of the body
What are the 6 different structural features of the alveoli
Large surface area short diffusion pathway capillary network diffusion gradients moisture surfactant
Why does the alveoli have a large surface area
Because there are millions of alveoli, providing more space for the gas molecules to pass through.
Why does the alveoli have a short diffusion pathway
Because the walls of the alveoli are made of squamous epithelial cells and are only one cell thick.
This reduces the distance these molecules have to diffuse through.
why does the alveoli have a capillary network
the capillary network is one cell thick and gives a short diffusion pathway to molecules.
why does a layer of moisture line the alveoli
A layer of moisture lines the alveoli because Gases can only diffuse across the membrane if dissolved.
Therefore the moisture allows gases to dissolve in order to cross.
What is surfactant
this is a chemical produced by the lungs to stop the alveoli from collapsing by reducing the surface tension of water
When does gas exchange take place
when the air reaches tiny sacs called alveoli,
What happens between the air in the alveoli and the blood in the capillaries?
gas exchange takes place between the air in the alveoli and the blood in the capillaries that surround the alveoli.
