Epidemiology Lab Report Essay

During the lab we took and measured the heartbeat of my lab partner twice and the blood pressure twice in different situations to measure the differences that occur. At the start my lab partner was calm resulting in the blood pressure to be around 125/59 with 55 beats per minute. The second time we did it, the numbers were fairly similar 126/59 and 62 beats per minute. At the beginning there is no action potential occurring or the pacemaker is not racing to make the heart beat quicker because the body is not using much energy since it is basically at a resting state. You can detect the heart beats by using the QRS EKG method where each one can represent a heartbeat that has occurred. There are fairly quick when they occur and by being able to view
them we can calculate the change of heartbeats when one goes from resting to doing something active.
The heart’s heart beat is controlled by a pacemaker the SA node. The heartbeat increases when things like adrenaline release hormone receptors. Thus there is a leaky NA channel which then releases Na into the pacemaker which changes the voltage inside the pacemaker.
The change of voltage than opens the gradient of NA which allows many to go in and then a K+ channel has to open as well to get it back to its normal stage. The heart beat occurs due to an electrical impulse that moves through the system of the heart. We can insure that the electrical impulses occur through the EKG. The electrical impulses are important because the voltage is what allows for the pacemaker to beat quicker or slower. In the heart Action potential proceeds around the heart which causes the heart to beat around 60 to 100 beats per minute. When checking with the EKG the heart beats per minute averaged around 72 heart beats per minute. We know that the action potential occurs through every phase it passes through the heart due to the fact that the heart contracts in and then relaxes as a beat occurs, and it can be seen through the EKG. It first begins in the SA node where it starts the impulse, then it is delayed at the Av node, then the impulses passes the heart apex and ventricular excitation begins, which leads to the ventricular excitation to be complete. As the impulses move around the heart it allows us to track the blood flow of the heart and the changes that occur in voltage or other areas within the
heart. This ensures that there is coordination of blood flow because as said before when tracking a heart beat you use an EKG. THE QRS method, at p-r there is a bit of potential, because this is when the voltage changes due to NA+ then there is a big spike and then suddenly it declines rapidly due to the K+ because it has to reach its potential than it regains its original potential and repeats itself every heartbeat. In order to know if blood is flowing through the heart, you need to check the blood pressure. Blood pressure is how fast the blood is circulating around your system, and as you start to exercise everything in your body increases due to the fact that you are using more energy. When Winston ran up the stairs and came back looking at the graph B below you can see that compared to the original graph, the spikes are more compacted together. This means the heart beats are happening a lot quicker and that means the blood pressure should also end up rising because the heart is working harder to pump blood in and out of the heart to get it all over the body. Finally from what I observed through the lab was that the differences within the resting and exercising show that the heart must change how quickly it beats, to get the blood flowing because if you’re resting and the heart is beating to fast or if it beats to slow, then that could lead to some problems since the pacemaker has to adjust to what our body is doing through the change of voltage that occurs through the leaky NA channels.