Summary
Summary Topic 11: Gas exchange in humans
Topic 11: Gas exchange in humans: IGCSE Biology course notes which will help you study for your papers. By studying these notes I achieved a 9 - A* on my Igcse
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
TOPIC 11: GAS EXCHANGE IN HUMANS11.1 THE BREATHING SYSTEM
-All gas exchange surfaces have features in common
-These features allow the maximum amount of gases to be exchanged
across the surface in the smallest amount of time
-They include:
→Large surface area to allow faster diffusion of gases across the surface
→Thin walls to ensure diffusion distances remain short
→Good ventilation with air so that diffusion gradients can be maintained
→Good blood supply to maintain a high concentration gradient so
diffusion occurs faster
The Intercostal Muscles
-Muscles are only able to pull on bones, not push on them
-This means that there must be two sets of intercostal muscles; one to
pull the rib cage up and another set to pull it down.
-One set of intercostal muscles is found on the outside of the ribcage
(the external intercostal muscles)
-The other set is found on the inside of the rib cage (the internal
intercostal muscles).
-There are 2 sets of intercostal muscles: the external, on the outside of
the rib cage, and the internal, on the inside of the rib cage.
The Function of Cilia & Mucus
-The passages down to the lungs are lined with ciliated epithelial cells
-Cilia cells have tiny hairs on the end of them that beat and push mucus up the
passages towards the nose and throat where it can be removed
-The mucus is made by special mucus-producing cells called goblet cells (shaped
like a cup).
-The mucus traps particles, pathogens like bacteria or viruses, and dust and
prevents them getting into the lungs and damaging the cells there.
-Mucus traps particles, dust and pathogens and cilia beat and push it up and away from the lungs.
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 alejandrahuartealfaro. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £4.27. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
77858 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