Question

Which of the following is the importance of respiratory system?

• A. Regulating pH of the blood by controlling how much oxygen is dissolved in the plasma
• B. Regulating pH of the blood by controlling how much carbon dioxide is dissolved in the plasma
• C. Regulating blood pressure by releasing hormones from the lungs that control heart rate
• D. Playing a role in regulating the level of cholesterol in the blood
• E. Obtaining some nutrients, such as vitamin K, from the atmosphere when supplies are limited

Answer 1

The correct option is B Regulating pH of the blood by controlling how much carbon dioxide is dissolved in the plasma

$Solution1$

Respiratory system functions mainly

in supplying oxygen to the body, and

removing carbondioxide from the body.

The partial pressure of $C{O}_2$ in the blood

plasma determines the respiratory rate,

which intern maintains normal pH of $7.4$

in the blood plasma.

mechanism

$\bullet$ when pH becomes acids (below 7.4) $\to$ respiratory

rate $\uparrow$ sec $\to \downarrow$ sec $C{O}_2$ dissolved in the plasma.

$\bullet$ when pH becomes alkaline (above 7.4)$\to$ respiratory

rate $\downarrow$ sec $\to \uparrow$ sec $C{O}_2$ dissloved in the plasma.