Question

rhythmic ______ contraction maintain the level of carbon dioxide in the blood and increase or decrease the breathing rate to maintain the blood ph level

Answer 1

Explanation:

Control of Breathing

Respiration is controlled by the respiratory center in the brain stem in response to CO2 levels. Medulla Oblongata sets the basic rhythm of breathing (pacemaker). Pons smooths out respiratory rate and influence depth and length of respiration.

Answer 2

Answer:

Diaphragm

Explanation:

Diaphragm is the main muscle which helps in inspiration and expiration, thus regulating the levels of Carbon dioxide and pH in the blood.

Lower levels of pH (high levels of acid) in the blood stimulates specific areas in the medulla, which increases the rate of respiration thus removing more carbon dioxide and subsequently lowering the level of acid produced.

P.S: Most of the acid in the blood is in the form of HCO3-, which is formed from CO2. Thus removing more CO2 decreases the acid level in the blood.