Lesson 4 and 5 - gas dxchange at the alveoli Flashcards
What are the three main factors that affect gas diffusion in the alveoli?
- Large surface area
- Short distance
- Diffusion gradient
How does large surface area affect gas diffusion?
The larger the surface area, the more gas can diffuse. Breathing deeper allows air to reach more alveoli, increasing oxygen diffusion into the blood.
What role does short distance play in gas diffusion?
The walls of the alveoli and blood capillaries are very thin and close together, allowing for quick diffusion.
What is a diffusion gradient?
Gases move faster when there is a bigger difference in concentrations. Breathing adds oxygen to the alveoli, and the bloodstream takes it away.
How are alveoli adapted for efficient gas exchange?
Alveoli have thin, moist walls for gas passage and are surrounded by many blood capillaries.
What is the size of an alveolus?
Alveoli are very small, only 0.2mm in diameter, contributing to a spongy texture and enormous surface area of the lungs.
What is gas exchange?
Gas exchange is the diffusion of oxygen from the alveolus into the blood.
What is gas exchange?
Gas exchange is the diffusion of oxygen from the alveolus into the blood and the diffusion of carbon dioxide from the blood to the alveolus.
What does blood carry into the lungs?
Blood carries carbon dioxide produced by respiration in all the cells of the body.
What are the features of alveoli?
Alveoli have a large number and are folded, thin walls (1 cell thick), moist walls, permeable (small holes in the walls), and an extensive blood supply.
What is the function of alveoli?
Alveoli provide a large surface area, allow for short distances for gases to diffuse, help gases dissolve in moisture, and maintain a high rate of diffusion.
How does gas exchange occur in the lungs?
Oxygen-rich blood is taken away from the lungs and carbon dioxide-rich blood is taken to the lungs.
What is the surface area of all the alveoli?
The total surface area of all the alveoli is about 70m², the size of a tennis court.
How many alveoli are there in the lungs?
There are about 700 million alveoli in the lungs.
How does the surface area of alveoli compare to skin?
The surface area of alveoli is between 30-40 times the area of the skin.
