1. Based on the results from Table 1, there were position-dependent and exercise-dependent changes in the heart rate. It appears that the post-exercise pulses were greater than the standing pulse, and that the standing pulses were greater than the resting pulses. These changes can be explained by the effects of force of gravity that occurs in these different positions. After an exercise, a person tends to have a greater heart rate in order to pump oxygen to the muscles. When a person is standing their heart rate will increase to pump blood against the force of gravity to the brain. In contrast, a person tends to have a lower heart rate in the sitting position because the effects of the force of gravity are less than in the standing position. …show more content…
The results from Table 3 show my P, QRS, and T wave during my three cardiac cycles. The amplitude of P, QRS, and T wave is not always the same for each cardiac cycle. However, the numbers for each wave are very close in range of the previous cycle. The differences in each wave can be explained by the depolarization and repolarization of the ventricular and atrial valves of the heart.
6. Based on Tables 3 and 4, the wave that had the largest amplitude was the R wave. The R wave tends to have greater amplitude than the other waves because physiologically the P wave (atria) is much smaller in muscle mass compared to the QRS complex (ventricles) which causes the P wave to generate less electrical activity.
7. The three different waveforms are a representation of electrical activity of the heart. The P wave represents the depolarization of the atrial valve. The QRS complex represents the depolarization of the ventricular valve. Also, the T wave represents the repolarization of the ventricular valve. The change in amplitude represents the different heartbeat patterns such as normal, fast, slow, or irregular heartbeats.
8. In addition, the waveforms of the other subjects do not have the same amplitudes. This can be explained by the different heartbeat patterns, type of movements, and positions (resting, sitting, or standing) that occurred during the ECG
There are several different heart problems that show up as an abnormal EKG reading. For example, a heart block can occur when there is a delay in the signals coming from the SA node, AV node, or the Purkinje fibers. However, clinically the term heart block is used to refer to an AV block. This delays or completely stops communication between the atria and the ventricles. AV block is shown on the EKG as a delayed or prolonged PR interval. The P wave represents the activity in the atria, and the QRS complex represents ventricular activity. This is why the PR interval shows the signal delay from the AV node. There are three degrees of severity, and if the delay is greater than .2 seconds it is classified as first degree. Second degree is classified by several regularly spaced P waves before each QRS complex. Third degree can be shown by P waves that have no spacing relationship to the QRS complex. Another type of blockage is bundle branch block. This is caused by a blockage in the bundle of His, creating a delay in the electrical signals traveling down the bundle branches to reach the ventricles. This results in a slowed heart beat, or brachycardia. On an EKG reading this is shown as a prolonged QRS complex. A normal QRS is about .8-.12 seconds, and anything longer is considered bundle branch block. Another type of abnormal EKG reading is atrial fibrillation, when the atria contracts very quickly. On the EKG this is shown by no clear P waves, only many small fibrillating waves, and no PR interval to measure. This results in a rapid and irregular heartbeat. On the other hand, ventricular fibrillation is much more serious and can cause sudden death if not treated by electrical defibrillation.
In this lab, I took two recordings of my heart using an electrocardiogram. An electrocardiogram, EKG pg. 628 Y and pg. 688 D, is a recording of the heart's electrical impulses, action potentials, going through the heart. The different phases of the EKG are referred to as waves; the P wave, QRS Complex, and the T wave. These waves each signify the different things that are occurring in the heart. For example, the P wave occurs when the sinoatrial (SA) node, aka the pacemaker, fires an action potential. This causes the atria, which is currently full of blood, to depolarize and to contract, aka atrial systole. The signal travels from the SA node to the atrioventricular (AV) node during the P-Q segment of the EKG. The AV node purposefully delays
In this figure, SN = sinus node; AVN = AV node; RA = right atrium; LA
In this article, it tells how an EKG scan is on grid paper and each small block, which is one millimeter (mm) long, represents 0.04 seconds and each larger box, which is five millimeters long, represents 0.2 seconds. On a EKG scan, the voltage of the heart is measured in millivolts (mV) along the y-axis. On the scan grid, ten millimeters is equal to one millivolt. According to this source, in order to calculate the beats per minute (BPM), one divides the number of number of large boxes between each heart beat (QRS wave) in 300 small boxes. However, that used for a more consistent and steady heart rate. For a more varied and irregular rhythm, one has to count the number of QRS waves in six seconds and then multiply that number by ten. For an example, if there are eight QRS waves, then the estimated heart rate would be 80
Two heart sounds are normally heard through a stethoscope on the chest wall, "lab" "dap". The first sound can be described as soft, but resonant, and longer then the second one. This sound is associated with the closure of AV valves (atrioventricular valves) at the beginning of systole. The second sound is louder and sharp. It is associated with closure of the pulmonary and aortic valves (semilunar valves) at the beginning of diastole. There is a pause between the each set of sounds. It is a period of total heat relaxation called quiescent period.
The first participant measured her pulse rate for 30 seconds before starting the exercise. Her pulse rate was calculated to determine the number of beats per minute. She then stepped on the platform (up and down) and continued at a slow pace for 3 minutes. After three minutes of the exercise, she measured her pulse rate every minute to determine her recovery time. This process was repeated until her pulse rate returned to normal.
The study of cardio physiology was broken up into five distinct parts all centering on the cardiovascular system. The first lab was utilization of the electrocardiogram (ECG). This studied the electrical activities of the heart by placing electrodes on different parts of the skin. This results in a graph on calibrated paper of these activities. These graphs are useful in the diagnosis of heart disease and heart abnormalities. Alongside natural heart abnormalities are those induced by chemical substances. The electrocardiogram is useful in showing how these chemicals adjust the electrical impulses that it induces.
State: The cardiac cycle is composed of five stages which each trigger the relaxation or contraction of the atria or ventricles and direction of blood flow.
The purpose of this experiment was to gather data on how the amount of time spent active impacts the speed of heart rate in beats per minute. The hypothesis stated that if the amount of time active is lengthened then the speed of the heart rate is expected to rise because when one is active, the cells of the body are using the oxygen quickly. The heart then needs to speed up in order to maintain homeostasis by rapidly providing oxygen to the working cells. The hypothesis is accepted because the data collected supports the initial prediction. There is a relationship between the amount of time spent active and the speed of heart rate: as the amount of time spent active rose, the data displayed that the speed that the heart was beating at had also increased. This relationship is visible in the data since the average resting heart rate was 79 beats per minutes, while the results show that the average heart rate after taking part in 30 seconds of activity had risen to 165 beats per minute, which is a significantly larger amount of beats per minute compared to the resting heart rate. Furthermore, the average heart rates after 10 and 20 seconds of activity were 124 and 152 beats per minute, and both of which are higher than the original average resting heartbeat of 79.
= The results that I have gathered from my experiment I have put into graph form. From my results I have found out that the more I exercise the longer I exercise the longer it takes for my pulse to return to normal, I think that I did not reach my potential maximum heart rate because the exercised was not strenuous enough for my body. I also discovered that when taking my pulse it takes a few seconds for the strong pulse to get back to the surface.
The two major things that will help an athlete while measuring the cardiovascular drift are progression and hydration levels. The heart rate of an athlete working hard during a workout should be no more than their maximum heart rate which is found by, if you’re a female take 226-age, if you’re a male take 220-age. If while doing a workout the maximum heart rate is exceeded by too much it may be necessary to take a break or slow down greatly. This may also help with traking the hydration of an athlete. If an athlete stays hydrated their core temperature will stay regulated which means they won’t sweat as much, which also means the heart won’t be under as much stress while transporting the oxygenated blood throughout the body to the
Investigating the Effect of Exercise on the Heart Rate Introduction For it's size the heart has the huge capacity of pumping large amounts of blood, in the average adult's heart beats 60 to 100 times a minute, pumps between 70ml and 100ml of blood with each beat, circulates 5 to 6 litres of blood around the body per minute and about 13 litres of blood per minute during vigorous exercise. The heart will beat more then 2.5 billion times during an average lifetime. This investigation will be looking at the effect of exercise on the heart rate. Aim The aim of this investigation is to find out how exercise affects the heart rate, using research & experimenting on changes and increases in the heart rate using exercise. Research â— The heart The normal heart is a strong, hardworking pump made of muscle tissue.
The heart is a pump with four chambers made of their own special muscle called cardiac muscle. Its interwoven muscle fibers enable the heart to contract or squeeze together automatically (Colombo 7). It’s about the same size of a fist and weighs some where around two hundred fifty to three hundred fifty grams (Marieb 432). The size of the heart depends on a person’s height and size. The heart wall is enclosed in three layers: superficial epicardium, middle epicardium, and deep epicardium. It is then enclosed in a double-walled sac called the Pericardium. The terms Systole and Diastole refer respectively and literally to the contraction and relaxation periods of heart activity (Marieb 432). While the doctor is taking a patient’s blood pressure, he listens for the contractions and relaxations of the heart. He also listens for them to make sure that they are going in a single rhythm, to make sure that there are no arrhythmias or complications. The heart muscle does not depend on the nervous system. If the nervous s...
In a normal strip, one can clearly identify a P wave before every QRS complex, which is then followed by a T wave; in Atrial Fibrillation, the Sinoatrial node fires irregularly causing there to be no clear P wave and an irregular QRS complex (Ignatavicius & Workman, 2013). Basically, it means that the atria, the upper chambers of the heart, are contracting too quickly and no clear P wave is identified because of this ‘fibrillation’ (Ignatavicius & Workman, 2013). Clinical Manifestations and Pathophysiology A normal heart rhythm begins at the sinoatrial node and follows the heart's conduction pathway without any problems. Typically the sinoatrial node fires between 60-100 times per minute (Ignatavicius & Workman, 2013).
Scientific interest in the heart goes back centuries. Some of the most basic understandings about the operation and specifically the electrical currents of the heart were discussed during the May 17, 1888 Proceedings of the Royal Society of London by Professor J.A. McWilliam of the University of Aberdeen. The following conclusions were based on his studies of mammalian hearts in cats, dogs, rabbits, rats, hedgehogs, and guinea-pigs.