Exchanging Substances Revision Notes and Practice Quiz
You need to know about a few examples of exchange surfaces. Mammals exchange gases in their lungs and absorb nutrients in their small intestines. In plants, gas exchange occurs in the leaves. In fish, gas exchange occurs in the gills.
The gas exchange in humans is in the following way. The lungs are responsible for transferring oxygen to the blood and removing carbon dioxide. Millions of little air sacs, called alveoli, accomplish this within the lungs.
Capillaries surround the alveoli, which are microscopic blood vessels. The air contains a higher concentration of oxygen than the blood, so oxygen diffuses from the air into the blood through the capillaries. Carbon dioxide diffuses the opposite way. A small tube called a bronchiole transports air between the alveoli and the outside world.
Alveoli are specialized to maximize oxygen and carbon dioxide CO2 diffusion.
Alveoli has the following specialised features:
Get full access for as little as £4.90 a month! 🤯
This post is for Premium Plan subscribers. Sign up now and upgrade your account to read this post and get access to our entire library of learning notes and revision quizzes for as little as £4.90 a month! 😲
