Unit 3 - Exchange surfaces and The Breathing System Flashcards
What are exchange surfaces used for?
Exchanging substances with the environemt
Give 2 examples of exchange surfaces in a plant?
Spongy mesophyll layer and the roots
How are roots and the mesophyll layer adapted?
By having increased surface areas
Name 2 exchange surfaces in the human body? And what do they exchange?
The alveoli (intestines) - CO2 and O2
The villi (lungs) - Glucose, amino acids etc
How are the alveoli adapted for gaseous exchange?
- Increased surface area by folding
- Dense capillary network (brings a constant supply of blood, this maintains the concentration gradient between the inside/outside of the body
- Thin 1 cell thick walls which creates a short diffusion distance
Label this diagram of the breathing system
!!!!!!!!!!!!!!!!!!!
What is ventilation?
The movement of air in and out of the lungs
What is the diaphragm and what does the diaphragm do?
A muscle underneath the lungs which causes the lungs to inflate and deflate
What does the ribcage do?
Explands and contracts to allow the inflation and deflation of the lungs
What does the intercostal muscle do?
Allows the ribcage to expand and contract
What does the trachea do?
Connects the lngs to the mouth
What do the rings of cartilage do?
Holds open the cartilage
Why are the rings of cartilage shaped as they are?
So they can stretch to allow more air
Explain inhailing
- Diaphragm contracts and flattens
- Intercostal muscles contract and move the rib cage up and out
- More space is created inside the thorax and air pressure drops inside the lungs
- As the air pressure outside the lungs is higher, air moves into the loungs to equalise the pressure
Explain exhailing
- Diaphragm relaxes and moves up
- Intercostal muscles contracts and ribcage moves down and in
- Less space in thorax and air pressure increases inside the lungs
- As the air outside the lungs has a low pressure air moves out to equalise it
