Proper week seven - Exchange surfaces

Echange surfaces

• Lungs
• Villii
• Stomata
• Root hairs

THe lungs are located in the thorax, beneath them is the diaphragm, a sheet of stong tissue with muscles attached. THe diaphragm can only move thanks to these diaphragm muscles. WHY NOT DIAFRAM?! They are behind the ribcage. The intercostal muscles of the ribcage can contract to draw the ribs up.

Two types of breathing.

Shallow: Diaphragm muscles contract and relax ( 14 breaths per minute at rest)

Deep: Diaphragm muscles contract and relax. Intercostal muscles of the ribs also contract and draw the ribcage up and out.

Bronchi>brochiole>alveoli

Alveoli are single ceslls in contact with a rich blood supply, they are moist and facilitate diffusion.




Air in Air out

N - Nitrogen (78%) N - Nitrogen (78%)

O2 - Oxygen (21%) O2 - Oxygen (16%)

CO2 - Carbon Dioxide (0.04%) CO2 - Carbon Dioxide (4&)


Respiration is the release of energy from glucose in cells - Anaerobic of anaerobic. All living things respire (virus doesn't respire independently)

Breathing is moving air in and out of the lungs.


Root Hairs have a high surface are to absorb wate and mineral salts. THe surface area of roots and leaves has hairs to increase absorbtion of water.

Stomata (on leaves)

• Gaseous exchange
• Surface area for photosynthesis
• can open and close (fill with water)

There is more to add to this week, but it is late and I am tired. Modify later.