Breathing And Gas Exchange (P1)

Question 1

How are alveoli adapted for diffusion?

Answer 1

They have thin walls meaning that substances can diffuse into the alveoli easily
They have a high surface area to volume ratio which means that there is more area for diffusion

Question 2

Ventilation breathing in

Answer 2

While breathing in, the diaphragm and ribcage expand. The volume of the chest therefore increases so there is less pressure as there is a lower surface area to volume ratio

Question 3

Ventilation breathing out

Answer 3

The ribcage and diaphragm contract before expanding again, hence decreasing the volume and increasing the pressure

Question 4

Lung structure

Answer 4

Nasal cavity, tongue ,epiglotis lead into trachea and bronchiole leads into lungs containing alveoli. Surrounded by rib and intercostal muscles. Heart in the middle and diaphragm underneath

Question 5

Ribs function

Answer 5

Contract and expand to allow breathing, protection

Question 6

Trachea function

Answer 6

Carries air in and out of the lung

Question 7

Trachea adaptations

Answer 7

Large cavity

Cartilage rings keep it open

Question 8

Heart adaptations

Answer 8

Made of muscle
Pacemaker cells
Lots of mitochondria
Efficient blood supply maintains concentration gradient
Valves prevent backflow