Describe and explain how the countercurrent system leads to efficient gas exchange across the gills of a fish? (3 marks)
1. Water and blood flow in opposite directions. 2. Maintains concentration gradient. 3. Along whole length of gill.
1 of 10
Describe how oxygen in the air reaches capillaries surrounding alveoli in the lungs? (4 marks)
Oxygen from the air moves down the trachea, bronchi and bronchioles into the alveoli. This movement happens down a pressure gradient. Once in the alveoli, the oxygen diffuses across the alveolar epithelim, then the cappilary endothelium.
2 of 10
Use your knowledge of leaf structure to suggest three other adaptations that the leaves might have that enable the plants to grow well in dry conditions? (3 marks)
Describe how oxygen in air in the alveoli enters the blood in capillaries? (2 marks)
Diffusion across alveolar epithelium/capillary endothelium
4 of 10
Abdominal pumping increases the efficiency of gas exchange between the tracheoles and muscle tissue of the insect. Explain why? (2 marks)
More oxygen enters so maintains concentration gradient.
5 of 10
Name the process by which oxygen passes from an alveolus in the lungs into the blood? ( 1 mark)
simple diffusion
6 of 10
Describe 2 adaptations of the structure of alveoli for efficient gas exchange? ( 2 marks)
Thin walls ( the alveolar epithelium is only one cell thick) + Total surface area is large.
7 of 10
People who have been fire breathers for a long time find they can not breathe out properly, explain why? ( 2 marks)
Loss of elasticity so less recoil.
8 of 10
Explain how downward movement of the diaphragm leads to air entering the lungs? ( 2 marks)
1.Increases volume in lungs. 2. Lower pressure in lungs. 3. Air pushed in down pressure gradient
9 of 10
What is the equation for pulmonary ventilation?
tidal volume x ventilation rate
10 of 10
Other cards in this set
Card 2
Front
Describe how oxygen in the air reaches capillaries surrounding alveoli in the lungs? (4 marks)
Back
Oxygen from the air moves down the trachea, bronchi and bronchioles into the alveoli. This movement happens down a pressure gradient. Once in the alveoli, the oxygen diffuses across the alveolar epithelim, then the cappilary endothelium.
Card 3
Front
Use your knowledge of leaf structure to suggest three other adaptations that the leaves might have that enable the plants to grow well in dry conditions? (3 marks)
Back
Card 4
Front
Describe how oxygen in air in the alveoli enters the blood in capillaries? (2 marks)
Back
Card 5
Front
Abdominal pumping increases the efficiency of gas exchange between the tracheoles and muscle tissue of the insect. Explain why? (2 marks)
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