B2.2 Flashcards
What substances are needed by ( diffuse into ) the organism
Mineral ions, O2, H2O, glucose, amino acids
What substances need to be removed ( diffuse out ) of the organism
CO2, Urea ( liver cells )
SA:V formula
Surface area divided by volume
What happens to the surface area to volume ratio as the size of the cube increases
The bigger the volume is the surface area is smaller
What happens to the diffusion distance as the size of the cube increases
It increases
Why does a tapeworm need a big surface area to volume ratio
Nutrients diffuse directly into the organism quickly enough to sustain life as diffusion distances are short.
What affects the amount of each material that needs to be exchanged
Metabloic rate
What do lungs have to increase surface area
Alveoli
What does a small intestine have to increase surface area
Finger like villi and microvilli
What is your heart made of
Cardiac muscle
Which side of the heart has a thicker muscular wall
Left
What is the function of heart valves
The valves seperate the chambers and importantly prevent the back flow of blood
Where does the pulmonary things go to
The lungs
How much does a heart beat per min
70
Why is it bigger on the left
It allows it to contract with more force and generate a greater blood pressure as it is going all around the body instead of just the lungs
