question_answer

  What happens to the rate of breathing during vigorous exercise and why?

Answer:

                 

Artery	Vein	Capillary
1. Thick-walled.	1. Thin-walled.	1. Thin-walled.
2. Carries blood from the heart to other parts of the body.	2. Carries blood from different organs to the heart.	2. Capillaries are involved in the exchange of food material, respiratory gases, and body wastes.
3. Situated deeper under the skin.	3. Situated just under the skin.	3. Occur at the terminals of artery and vein.