Question

A CO2 level in the blood increase due to exercise, and thus the blood pH decreases. This decrease in pH stimulates which of the following brain structure to send neural impulses to the sinoatrial node, thus increasing cardiac output?

a) Medulla oblongata
b) Corpus callosum
c) Cerebrum
d) Temporal lobe

Answer 1

The increase in CO2 and decrease in blood pH due to exercise stimulates the medulla oblongata to send signals to increase cardiac output, with the medulla oblongata being the correct answer to the question.

Step-by-step explanation:

When levels of carbon dioxide in the blood increase, typically due to exercise, this leads to an increase in hydrogen ion concentration, causing a decrease in blood pH. This physiological change stimulates chemoreceptors that in turn signal specific areas of the brain responsible for respiratory and cardiovascular responses. The medulla oblongata is the brain structure that specifically sends neural impulses to the sinoatrial node, increasing cardiac output to manage the elevated CO2 levels and the associated decrease in blood pH.

Therefore, an increase in CO2 levels during exercise, which leads to a decrease in blood pH, stimulates the medulla oblongata to send neural impulses that increase cardiac output. The correct answer to the question is a) Medulla oblongata.