|MadSci Network: Medicine|
Sorry for the late response. The cardiovascular system responds to exercise by increasing the activity level. The adrenal gland increases the production of the hormones adrenaline and nor adrenaline. These have direct effects on the heart. These hormones cause an increase in the heart rate and the force with which the heart contracts each beat. This increases the total amount of blood that is circulated in the body every minute. That increase in blood circulation is required to meet the increased demand for nitutrients and oxygen that the muscles and other tissure require during exercise or for that matter during any time that the metacbolic demand on the body is high. The blood vessels in non essential places places in the body also constrict during exercise and this provides extra blood volume for more essential organs such as the heart lungs and the brain. The lungs also play an important part in all of this. Their primary role is to exchange oxygen and carbon dioxide in the blood with fresh air./ This increases the amount of oxygen in the blood that comes to the lungs from the body and decreases the amount of carbondioxide in the blood. The lungs also increase their activity by increasing the number of breaths taken each minute and the amount of air taken in each breath. Together the increase in the activity of both these organ systems increases the amount of blood and oxygen supply to the body. Thanks
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