Which systems regulate blood ph?

Hi

There are two systems in the body that regulate blood pH

The first one involves our lungs via pulmonary ventilation. Here, the pH is proportional to [CO2]. The second system is the kidneys via the regulation of H+/HCO3- in cells of the collecting duct (nephron). In the kidneys, pH is proportional to [HCO3-]. During acidosis, there is a secretion of H+ ions and during alkalosis, there is a reabsorption of H+ ions. There is also the urinary buffer system, where you have bicarbonate in the urine, phosphate in the urine, and deamination and the ammonium ion (NH4+).

The question is exactly like this: The nurse is reviewing a client's blood ph level. which of the systems in the body regulate blood Ph? select all that apply
A.buffers
b.respiratory
c.renal
d.cardiac

A, B, C...

"Cardiac" is very off because are they referring to the heart or to the circulating blood?

Duddz

The answer key says a,b,d.... I think its wrong though.... im sure it is a.b.c thanks

I agree too.