The body is able to control the blood pressure in order to control the heart rate through a process called a Negative Feedback Loop. A Negative Feedback Loop means that the body is able to increase in one function which then causes a decrease in another. For example, the body is able to contract its vessels to increase blood pressure which then results in the pressure receptors sending a message to the brain which releases a chemical to slow the heart rate down. It all works in a type of chain and depending on what kind of activity you are doing certain things will happen inside your body. During exercise, such as running or cardio, your heart rate rises to meet metabolic requirements. A hormone in the body called epinephrine is why the heart rate increases during exercise. However during rest your body will keep the heart rate low in order to match the metabolic requirements once again but this time the body produces a chemical known as acetylcholine which causes the decrease in heart rate.
During respiration your lungs are being controlled through daytime and night-time and it is all controlled by the respiratory system. The respiratory system aids in maintaining homeostasis in the body. Oxygen is essential when breathing and it is delivered into your bloodstream. The oxygen is delivered into the bloodstream and the cells absorb the oxygen. When the body is at rest the breathing rate stays constant and steady. This means that a fair amount of oxygen is delivered into the bloodstream when you inhale and a fair amount of carbon dioxide exits the blood when you exhale. When doing activities, such as exercise, the oxygen levels in the blood decrease and the carbon dioxide levels increase. When you end the activity the respiratory system slows down the heart and breathing rate back down to maintain homeostasis in the bloodstream.
One of the most important examples of homeostasis is the regulation of body...