Gaseous exchange feedback

Can some one give me feedback on this?
When air is breathed in, it contains approximately 0.04% carbon dioxide and 20% oxygen.The air travels towards the alveolus. Gaseous exchange takes place via diffusion, the net movement of oxygen in the alveoli takes place as there is a lower concentration of oxygen in the blood stream than in the alveolus.The alveolus has special features , such as a thin wall between the alveolus and the blood stream, this allows oxygen to diffuse easily into the blood stream,. This is a feature that helps carbon dioxide to diffuse into the alveolus from the capillaries.As the carbon dioxide is more concentrated in the blood stream in comparison to the alveolus. When we breathe out, the air contains 4% carbon dioxide and 16% oxygen.
When oxygen enters the blood stream, it joins with haemoglobin and is transported back to the heart to be pumped to the body and the head for respiration.

Sounds good! Well written. I could techincally go into the anatomy of haemoglobin in the blood, and the reasons why it binds to oxygen and releases CO2, but that's more A-level stuff. Anyway, well written and well rehearsed. Say that in your exams you'll get full marks for your question!

Thank you very much and I'll try and go into the haemoglobin anatomy, thank you!

Can some one give me feedback on this?
When air is breathed in, it contains approximately 0.04% carbon dioxide and 20% oxygen.The air travels towards the alveolus. Gaseous exchange takes place via diffusion, the net movement of oxygen in the alveoli takes place as there is a lower concentration of oxygen in the blood stream than in the alveolus.The alveolus has special features , such as a thin wall between the alveolus and the blood stream, this allows oxygen to diffuse easily into the blood stream,. This is a feature that helps carbon dioxide to diffuse into the alveolus from the capillaries.As the carbon dioxide is more concentrated in the blood stream in comparison to the alveolus. When we breathe out, the air contains 4% carbon dioxide and 16% oxygen.
When oxygen enters the blood stream, it joins with haemoglobin and is transported back to the heart to be pumped to the body and the head for respiration.

It's all good if you don't but in case you wonder, things to look for include the Bhor shift/effect, affinity for oxygen and the quaternary structure of the haemoglobin within the blood cell

Do you do health and social care BTEC? anatomy and physiology?