Carbon dioxide levels in the blood and cerebrospinal fluid affect ph. this enables the organism to sense a disturbance in gas levels as

Medulla oblongata form the brain stem and is a long stem like structure. This regions controls the involuntary actions of the body like sneezing and vomiting. The respiratory center is present in the brainstem.

The increase in the carbon dioxide concentration in blood results in the lower pH of the body. This change of the body is detected by the medulla oblongata. The medulla oblongata is in direct contact with the cerebrospinal fluid and measures the change. This alters the breathing rate, controls breathing and maintains the pH level to normal.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.