Lecture notes
Gas exchange surfaces
- Module
- 9BN0
- Institution
- PEARSON (PEARSON)
A summary of mammalian gas exchange surfaces
[Show more]
Seller
Follow
Content preview
Trachea:Tube allowing air to travel to lungs
Rings of cartilage ensure tube remains open
Mucus traps dust and pathogens
Cilia waft mucus to top of trachea
Bronchi:
Thinner walls and smaller diameter than trachea
Bronchioles:
Large number of bronchioles in gas exchange system
Large ones have elastic fibres and smooth muscle
Alveoli:
Alveolar wall is a single layer of squamous (flattened) epithelium
Thin and permeable for easy diffusion
Surrounded by elastic fibres so they can stretch during inhalation
Carbon dioxide diffuses out of the capillaries and into the alveoli while oxygen diffuses from
the alveoli and into the capillaries
Oxygen and carbon dissolve in moisture to exchange occurs in solution
All organisms exchange gases with their environment via diffusion, e.g., aerobic respiration
and photosynthesis.
● The pleural cavity is filled with fluid.
● Bronchioles are made up of alveoli.
● An alveolus is an example of a gas exchange surface.
● The light purple parts are air spaces.
● The darker parts are the wall of the alveolus and capillaries.
alveoli (alveolus - singular)
● Air travels in and out of the alveoli.
● There is a layer of moisture in the alveolus.
● There is a high carbon dioxide level outside the alveoli and a low level inside them.
● Capillary walls are one cell thick, which creates a short diffusion distance.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller sophie69. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £7.16. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83662 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now