Each valve has a set of "flaps" (also called leaflets or cusps). The mitral valve normally has two flaps; the others have three flaps.
Dark bluish blood, low in oxygen, flows back to the heart after circulating through the body. It returns to the heart through veins and enters the right atrium. This chamber empties blood through the tricuspid valve into the right ventricle.
The right ventricle pumps the blood under low pressure through the pulmonary valve into the pulmonary artery. From there the blood goes to the lungs where it gets fresh oxygen. After the blood is refreshed with oxygen, it's bright red. Then it returns by the pulmonary veins to the left atrium. From there it passes through the mitral valve and enters the left ventricle.
The left ventricle pumps the red oxygen-rich blood out through the aortic valve into the aorta. The aorta takes blood to the body's general circulation. The blood pressure in the left ventricle is the same as the pressure measured in the arm.
To monitor the heart, scientists can use x-ray or scanning technology to get a picture. To really explore the heart, scientists have to perform surgery. Heart surgery is very risky because the heart's pumping action is so critical for survival. If the heart stops pumping, the body cannot survive. Before beginning heart surgery, doctors connect the patient to a machine that pumps the blood for the heart. Only then is it safe for the doctor to stop the heart in order to operate.
● Exercise
Lack of exercise increases the risk of heart disease. Lack of exercise is also related to other diseases such as obesity, diabetes, and high blood pressure. Even limited amounts of physical activity can be good for your heart if done regularly and over the long term.
Exercise helps your heart by:
- strengthening the heart muscle
- making the heart more efficient
- improving the flow of blood to the heart muscle and
- improving the heart's ability to handle stress
When we exercise our heart rate increases. This is because our muscles are working harder and need more energy. Our heart rate increases to supply more oxygen, carried in the blood, to these muscles. The oxygen is needed in the muscles for aerobic respiration, that is to break down glucose, which we get from food, into glycogen which is the main type of energy we use when we exercise.
Method
The experiment will be carried out by measuring the heart rate before and after exercise on a number of people.
The experiment procedure will go as follows:
● I will measure the resting rate of the group before any physical exercise & record the results.
● I will then begin the group exercising, the exercise will last for five minutes with 30 second breaks every 1 minute, this is so I can measure the heart rates of the group every 30 seconds and record it.
● When the exercise if completed I will measure the heart rate levels of the group once every minute until it returns to its original heart rate.
The group will consist of 3 people, these people will all start their exercise at different times so it is possible to measure the heart rates properly and sufficiently.
The group will all be doing the same exercise to make the test results as fair as possible, the exercise will be carried out as step ups, using 3 level steps.
I aim to make this experiment as fair as possible by timing the experiment as properly & accurately as possible, to do this I will be using a stopwatch.
I will record my results in a table & then continue to graph them when the experiment is over.
Prediction
I predict that the whole groups heart rate’s will increase during exercise, although I do not believe that all three group members rates will be the same. I believe this because the fitness levels in each group member varies.
I believe that the heart rate’s will increase because during exercise it is clear that the muscles being used will need more oxygen, this is because of the aerobic respiration taking place in the muscles. All muscles being used will need more oxygen, including lungs.
I have learnt this from my research and believe my predictions will be correct.
Results
BPM = Beats per minute
- During exercise
- After exercise
- Average
- Result graph
Conclusion
As I predicted the heart rates increased and were at their highest after 5 minutes of exercise, this is because of aerobic respiration, the group members muscles were working harder and therefore needed more oxygen when exercising.
The lowest BPM were at the resting stage in the beginning and the resting stage at the end of the experiment. The highest number of BPM was at the 5 minute mark into the exercise and the lowest number of BPM was at the 5 minute mark after finishing exercising.
Persons 1 and 2’s hearts seemed to be nearly on par whereas person 3 seemed to have a higher heart rate then the first two, maybe this is because the 3rd person smokes and is slightly more overweight then the first 2.
I believe re-doing the experiment a number of times would enhance the ultimate accuracy of this investigation but I believe the results seem to be accurate enough and correct as well as supporting my predictions.
Evaluation
I believe my experiment went well, I listed the results accurately, timed the experiment accurately and made sure the group all exercised for the accurate amount of times and a similar pace.
The ways in which I could of improved my investigation was perhaps, using a larger group, doing the experiment more then twice to make sure my results are as accurate as I can possibly get them and to use people of the same fitness, height, weight & people that do not smoke.
