Breathing, gaseous exchange and respiration

Question 1

explain how oxygen enters the body.

Answer 1

1. oxygen is inhaled (breathing).
2. oxygen enters the alveoli.
3. The oxygen diffuses across the alveoli into the blood capillaries.
4. This blood contains oxygen.

Question 2

what is the largest artery in the body?

Answer 2

the aorta

Question 3

what does the aorta do ?

Answer 3

subdivides to form smaller arteries