2.7 Absorption of Materials Flashcards
What must oxygen and nutrients from food be absorbed into?
The bloodstream to be delivered to cells for respiration.
Why do tissues contain capillary networks?
To allow the exchange of materials at a cellular level.
Surfaces involved in the absorption of materials have certain features in common to increase the efficiency of absorption. What are these features?
Large surface area
Thin walls
Extensive blood supply
Where does gas exchange happen?
In the alveoli in the lungs.
In alveoli, what is the direction of gas movement?
Oxygen in, carbon dioxide out.
Where are the gases exchanged?
The blood capillaries surrounding the alveoli.
Name the 3 ways alveoli are adapted for diffusion.
1 - They have a large surface area
2 - They have a good blood supply
3 - They have thin walls (one cell thick) for more efficient diffusion.
What happens in the small intestine?
Absorption of nutrients.
What does the small intestine contain millions of?
Villi
State the water soluble food products.
Glucose and amino acids.
Where are water soluble food products absorbed into?
The blood capillary.
Name the fat soluble food products.
Fatty acids and glycerol.
Where are fat soluble food products absorbed into?
The central lacteal
