The Lungs And Breathing Flashcards
What is diffusion?
The net movement of particles of a gas or solute from an area of higher concentration to an area of lower concentration
Factors that would increase the rate of diffusion
- Steep concentration gradient
- Warmer temperature
- Distance travelled
- Mitochondria gives energy
- Surface area to volume ratio
Exchange surface
A surface where materials are exchanged between an organism and it’s environment
Why do Multicellular organisms need exchange surface?
As multicellular organisms are more metabolically active, they need to exchange more substances with their environment
Why do exchange surfaces need a large surface area
In the same time period, more particles can diffuse across the exchange surface
Why do exchange surfaces need thin walls
Diffusion is slow, so a shorter distance means this takes less time
Why do exchange surfaces need a good blood supply and a supply of new materials
It maintains a steep concentration gradient
What are alveoli
Air sacs in the lungs where gas exchange occurs
What substances are exchanged in gaseous exchange and in which direction?
- Oxygen in
- Carbon dioxide out
Adaptations of the alveoli
- Ventilation to maintains a steep diffusion gradient
- Very thin walls give a short distance for diffusion
- Spherical shape further increase surface area for diffusion
- Good blood supply to maintain concentration gradient
Breathing
The physical movement of air in and out of the lungs
Respiration
A chemical process where energy is released from the breakdown of food
Gas exchange
The exchange of oxygen and carbon dioxide between the air in the alveoli and the blood
Nose
Opening that air from outside can enter and leave the body
Trachea
Tube that takes air from the nose/mouth towards the lungs
