Exchange of gases in the lungs

HideShow resource information
  • Created by: patricia
  • Created on: 21-11-13 18:56
What characteristic of the alveol functions to speed up rate of gaseous exchange?
Large surface area to volume ratio
1 of 17
Why is the aveoli wall thin ( one layer of epithelial cells)?
To provide a short diffusion pathway
2 of 17
To allow selected materials to diffuse easily?
The membrane must be partially permable
3 of 17
What does the alveoli also need to maintain?
A steep concentration gradient of gases across the exchange surface
4 of 17
What is the environmental medium?
Air- to maintain diffusion gradient
5 of 17
What is the internal medium?
Blood- to maintain a diffusion gradient
6 of 17
Explain why the rate of diffusion increases with the increase of temperature?
Because molecules have enough kinetic energy- movement
7 of 17
Describe the process of the gaseous exchange - oxygen
1) Oxygen diffuses out of the alveoli pass the alveolar epithelium and the capillary endothelium , and into the blood
8 of 17
Describe the process of the gaseous exchange - carbon dioxide
Carbon dioxide diffuses from the capillary endothelium, alveolar epithelium into alveoli and is breathed out
9 of 17
How does the alveoli have a good blood supply? How is it good as function?
Good blood supply from capilleries so that they can constantly take away oxygen and more carbon dioxide maintaining the concentration gradient
10 of 17
Describle ficks law
Diffusion is proportionl to : surface area x difference in conc gradient / length of diffusion pathway
11 of 17
What is the factor that allows more time for diffusion?
Red blood cells slow as they pass the pulmonary capillary/ capillary endothelium
12 of 17
How does the "wall of each alveolus is not more than 0.3um thick" contribute to the effeciency of gas exchange in the alveoli?
The rate of diffusion is more rapid the shorter the distance the gases diffuse
13 of 17
How does the "There are 300 million alveoli in each lung" contribute to the effeciency of gas exchange in the alveoli?
There is very large surface area in 600 million alveoli (2 lungs) and this makes diffusion more rapid
14 of 17
How does the "Each alveolous is covered by a dense network of pulmonary blood capilleries contribute to the effeciency of gas exchange in the alveoli?
Diff is more rapid the greater the diffu gradient. Pumping blood through the capilleries removes 02 as it diffuses from the alveoli into the blood. The supply of new CO2 as it diff out of the blood helps to maintain a conc gradi
15 of 17
How does the "each pulmonary capillary is narrow" contribute to the effeciency of gas exchange in the alveoli?
Red blood cells are flattened against the c.wall to let them pass through.This slows them down, increasing the time for gas exchange and reducing the diffusion pathway, thereby increasing rate of diffusion
16 of 17
How is the diffusionn pathway short?
Because alveoli wall has only one single layer of epithelial cell and blood capilleries have only one single layer endothelial cells
17 of 17

Other cards in this set

Card 2

Front

Why is the aveoli wall thin ( one layer of epithelial cells)?

Back

To provide a short diffusion pathway

Card 3

Front

To allow selected materials to diffuse easily?

Back

Preview of the front of card 3

Card 4

Front

What does the alveoli also need to maintain?

Back

Preview of the front of card 4

Card 5

Front

What is the environmental medium?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Human, animal and plant physiology resources »