Surface area : Volume ration + Lungs Flashcards
What does surface area determine
How quickly an organism can get nutrients by diffusion or absorption
Metabolic rate
The amount of energy expended by the organism in a time period , usually daily
What does volume determine
Determines how much nutrients an organism needs
Metabolic demand
How much oxygen and nutrients an organism needs to take in daily to respire enough to maintain that metabolic rate
Ventilation (breathing
Movement of air into and out lungs
Respiration
: Chemical reaction to release energy
Gas exchange
Diffusion of oxygen from the air in the alveoli into the blood and carbon dioxide from the blood into the air out of the alveoli
Antagonistic
One muscle relaxed whilst another is contracted a tthe same time
When breathing in (Inspiration)
External intercostal muscles contract
Internal intercostal muscles relax
Diaphragm goes down to create more volume in the lungs
Pressure decreases due to this
Air goes into the lungs as the pressure gradient is high to low in the lungs
When breathing out (Expiration)
External intercostal muscles relax
Internal intercostal muscles contract
Diapragm goes up to create less volume in the lungs
Pressure increases due to this
Air goes out the lungs as the pressure gradient is high to low in the air
What do the alveoli sacs contain to stop sticking
Liquid surfactant
How does oxygen move from the alveoli to the capillaries
Oxygen in the alveoli sacs is highly concentrated so oxygen diffuses into the blood as it is low concentrated in there and they are right next to eachother
Features of capillary that help diffusion
Thin permable walls
