When John begins to run, his muscles utilize oxygen and produce carbon dioxide. His body has receptors monitoring these conditions. When the levels stimulate a receptor, the heart rate and respiratory rate elevate to accommodate the change. This is an example of a reflex.

Cardiovascular telex.

Explanation: During physical exercises which involves running, there is a reduction in the systemic vascular resistance produced and these constitutes a change in the heart rate and respiratory rate caused by the neural mechanisms which control the cardiovascular system which regulate the circulation of adequate oxygen supply and release carbon dioxide.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.