Arterias, venas y capilares.
I believe the primary determinant of basal metabolic rate is the Lean Body Mass. Basal metabolic is the rate of energy expenditure per unit time by animals at rest. It comprises the processes that the body requires to function. It is the amount of energy per unit time that a person need to keep the body operational at a state of rest.
The slightest change in pH can destroy the substance or organism. The pH of a cell's interior helps regulate the cell's chemical reactions. For example, the pH of blood is 7.4, if blood falls to 6.8 or lower or 8.2 or higher, it results in death.
Answer:
Tubules?
Explanation
The trachea, spiracle, and air sac are part of their respiratory system, Howeber, the tubules are what take away the carbon dioxide from their system. Im not sure if they produce the carbon dioixde. But they are a part of what removes the carbon-dioxide from their body.