
In humans, the medulla region of the brain is mainly responsible for the regulation process of respiration. It is also called the respiratory rhythm centre. The chemosensitive area located near the respiratory centre sends signals across nerve impulses to alter the rate of expiration to eliminate compounds.
In the United States the direction the continental polar air mass move South toward the Gulf of Mexico to replace the rising maritime tropical air mass.
Answer: Option A
<u>Explanation:</u>
Air masses are large bodies of air moving horizontally in a very uniform way. Continental polar air mass is an air mass that forms near the poles. It originates in northern Canada and Alaska and move south then East.
The continental polar masses are the causes for the severe cold weather in the South during the cold months. Maritime tropical mass are warm and have high moisture content. During winter it comes in contact with the continental polar mass hence getting stabilized.