Physioex 6

2. With the exception of the R-R interval, which time interval shows the greatest difference between resting and post- exercise? Explain this observation.

Resting heart contractions were recorded for thirty seconds until the heart rate was less than 60 beats per minute. A stimulator electrode to be used was set to the following states: Amplitude of 4.00 Volts, a stimulus delay of 50ms, stimulus duration of 10ms, a frequency of 1.0Hz, and a pulse number of 30. The electrode was then placed in direct contact with the heart for 30 seconds at which time the data was observed and recorded.

At the latter end of the p-q interval, atrial contraction occurs forcing additional blood into the ventricles. At the beginning of the QRS interval on an ECG reading, the mitral valve closes and the ventricles are at EDV (135ml). During the QRS interval, ventricular contraction occurs increasing the pressure in the ventricle and the aorta. When the pressure continues in the ventricle exceeds the pressure in the arteries, the aortic valve opens and blood is ejected. The increased pressure continues through the t peak. The ventricles are now in ESV (65ml) and the aortic valve is closed. Now the ventricles are relaxed causing pressure to fall and the cardiac cycle starts over again. This ECG reading was from a normal tracing. Keep in mind that an ECV is easy to obtain, but there are some subtleties that are very complex.

4. Atrial hypertrophy would probably have what effect on an electrocardiogram? *spike the p wave

The authors then share their analysis on the changes of heart rate and GSR at the many different points throughout their study.

4) Compare and contrast oscillations in heart rate observed at rest (Activity 1), during exercise and recovery exercise (Activity 2). Is the relative magnitude of the oscillations the same? Provide a physiological explanation in your answer.

B. Part B. PowerPhys Experiment 4 – Effect of Exercise on Cardiac Output (13 points total)

Table 2. This table shows the recording of the amplitude, period, and BPMs for the ventricular contractions before and the effects of the Warm Ringer’s after.

Once the patient was correctly hooked up to the EKG the BIOPAC Student Lab Program was started. Lesson five is the one we used for this experiment and once it had been chosen we label it and started the experiment. There were four conditions we needed to measure; the first being lying down. The subject was lying down relaxing on the cot. We clicked record and let it run for 20 seconds. The data resembled the chart below. If it did not we would have had to repeat the steps until it did.

If the resistance increases, cardiac output decreases and the blood pressure increase and if the resistance decreases, cardiac output increase and the blood pressure decreases. During each contraction, the amount of blood pumped out by one ventricle is stroke volume. The number of heartbeat in each minute is known as heart rate. The normal heart rate value for adult is 60-100 beats per minute. The cardiac output is directly proportional to the stroke volume and heart rate. The average arterial pressure during one cardiac cycle is mean arterial pressure (MAP), which is directly related to the cardiac output and resistance. The instrument sphygmomanometer with an air cuff attached to the reservoir is used to detect blood pressure associated with the pulse.

*Both sides of the heart are doing this at the same exact time and contracting/relaxing is what pumps the blood from one place to the other.

13. Define total heart block, and describe how it was recognized in the laboratory. No synchrony between depolarization waves

The atrial contraction is represented by the P wave. This is an upward, or positive wave of the line on the graph. The ventricular contraction is displayed by the QRS complex. The QRS

The patient should be seated with the feet flat on the floor. The BP is obtained in both arms,

amount of pressure exerted on arterial walls in the patient’s heart. Blood pressure is measured in