Flashcards
b3 -2
Flashcards do conjunto (6)
- 1Many organ systems are specialised for exchanging materials. The effectiveness of an exchange surface is increased by......■ having a large surface area
■ being thin, to provide a short diffusion path
■ (in animals) having an efficient blood supply
■ (in animals, for gaseous exchange) being ventilated. - 2What can effect the ability of organisms to exchange materials?The size and complexity of an organism increases the difficulty of exchanging materials.
- 3state 2 ways the humans are adapted to exchanging materials■ the surface area of the lungs is increased by the alveoli
■ the surface area of the small intestine is increased by villi. - 4Describe how the villi aid absorptionThe villi provide a large surface area with an extensive network of capillaries to absorb the products of digestion by diffusion and active transport.
- 5State the function of the breathing systemThe breathing system takes air into and out of the body so that oxygen from the air can diffuse into the bloodstream and carbon dioxide can diffuse out of the bloodstream into the air.
- 6Describe the process of ventilation ?To make air move into the lungs the ribcage moves out and up and the diaphragm becomes flatter. These changes are reversed to make air move out of the lungs. The movement of air into and out of the lungs is known as ventilation.