Pulse Rate Essay

1. What is blood pressure? Blood pressure is the strength/pressure exerted by circulating blood on the walls of our blood vessels. It is recorded as two numbers – the systolic pressure over the diastolic pressure. 2. Why is high blood pressure a problem? When blood pressure is high the heart is working to hard to get blood through your body and can cause heart attacks, strokes and even death, heart and kidney failure. (http://www.nhlbi.nih.gov/hbp/bp/bp.htm) 3. Why does increased physical activity raise heart rate? Increased physical activity increases oxygen demand as well as the need to remove excess carbon dioxide produced during cellular respiration. In order to meet oxygen needs our heart rate increases along with other respirations to supply our body with the necessary oxygen. (Muscles require more oxygen for cellular respiration and increased cellular respiration increases carbon dioxide in our body that triggers the increase of breathing and circulation rates.) 4. Why is heart rate lower in an individual who does aerobic exercise regularly? A lot of exercise will cause our heart muscle to pump more blood with each beat/contraction. If the volume of the blood being pumped with each contraction is greater than the rate of our heartbeat will be lower. 5. Why do some people feel faint when they go quickly from lying down to standing? Gravity causes blood pressure in the arteries/vessels going to our brain to drop when standing up quickly after laying down. This motion causes a sudden feeling of faintness until mechanisms in our body elevate our blood pressure in the vessels to normal again. 6. How and why does heart rate change with body position? Heart rate increases from lying down to standing up because more energy is required for our body to maintain in a standing/sitting position in comparison to lying down. Therefore the increased need for ATP increases cellular respiration that causes an increase need for oxygen and carbon dioxide levels in our body that triggers increased breathing so our heart rate increases as well. 7. From your study of the circulator system how would you describe a â€Å"fit† individual? A fit individual has an ability to contain a lot of oxygen by having an efficient respiration and circulatory system. When having these efficient systems their heart is allowed to pump more blood with each beat and the person can quickly recover from the stress of exercise(By returning their exercise pulse rate to their standing pulse rate) more quickly compared to a person who is not fit.