Heart Rate Labs

Lab 1:

Heart Rate and Blood Pressure

as Vital Signs

Systolic pressure (mm Hg)

Diastolic pressure (mm Hg)

Mean arterial pressure (mm Hg)

151 mm Hg 81 mm Hg 98 mm Hg

Table 1- Baseline Blood Pressure

DATA

Systolic pressure (mm Hg)

Diastolic pressure (mm Hg)

Mean arterial pressure (mm Hg)

134 mm Hg 73 mm Hg 90 mm Hg

Table 2- Blood Pressure Response to Cold

Table 3

Condition

Heart rate (bpm)

Time(s)

Resting heart rate

77.87 bpm 25.02 sec

Maximum heart rate

81.96 bpm 40.01 bpm

Rebound heart rate

77.84 bpm 180.2 sec

DATA ANALYSIS

1. Describe the trends that occurred in the systolic pressure, diastolic pressure, mean arterial pressure, and heart rate with cold stimulus. How might these responses be useful in a “fight or flight” situation?

- When the levels fluctuate it stimulates the senses therefore pushing the body one direction or another.

2. As a vital sign, blood pressure is an indicator of general health. A high blood pressure (140/90 or higher) increases the risk of cardiovascular disease and strokes. Collect the systolic and diastolic pressures for the class and calculate the average for each. Rate the class average blood pressure using the follow scale: class average is above high. 143/84

Blood Pressure Category

140/90 or higher High

120-139/80-89 Pre-hypertension

119/79 or below Normal

3. How long after immersion did your heart rate reach its maximum value? Explain the physiologic mechanism that led to this change in heart rate.

- About 15 seconds. The nerves felt the change n temp, and the loss of body heat, started pumping more blood to generate more heat to compensate for the loss whilst the foot is in the ice water.

4. Describe the changes in heart rate that occurred after the maximum value. How can you explain the minimum heart rate value? How would you explain the heart rate variations seen in the remainder of the experiment?

- The heart rate receded to its baseline state. The minimum heart rate value is taken when the body is stress free and at a physical rest point, therefore using the least amount of blood possible. More activity = larger blood flow.

5. How long after the maximum heart rate did it take to arrive at your rebound heart rate? What can you say about the relative speed of physiologic response to a stimulus vs. the speed of mechanisms that are designed to maintain homeostasis? - 140 seconds. Takes time to slow down the reaction that was already flowing, similar to stopping a fully loaded train traveling at 60 mph. It can’t stop on a dime.

• 6. If the heart rate is too slow there is inadequate blood pressure to maintain perfusion to the brain. This can lead to loss of consciousness (fainting). Keeping in mind the autonomic nervous system responses that you observed in this experiment, explain the sequence of events that results in a severely frightened person fainting.

• - Person becomes frightened, heart rate drops, blood levels drop, little blood reaches brain, brain restarts, if you will, and boots back up to speed to reach an adequate blood flow level.

Heart Rate, Blood Pressure,

and Exercise

Lab 2

DATA

Systolic pressure (mm Hg)

Diastolic pressure (mm Hg)

Mean arterial pressure (mm Hg)

Pulse (bpm)

123 mm Hg 75 mm Hg 99 mm Hg 79 bpm

Table 1- Baseline Blood Pressure

Systolic pressure (mm Hg)

Diastolic pressure (mm Hg)

Mean arterial pressure (mm Hg)

Pulse (bpm)

135 mm Hg 57 mm Hg 61 mm Hg 92 bpm

Table 2- Blood Pressure After Exercise

Condition Good

Resting heart rate (bpm) 92

Maximum heart rate (bpm)

75

Recovery time (s) 2 minutes

Table 3- Heart Rate

DATA ANALYSIS

1. Describe the trends that occurred in the systolic pressure, diastolic pressure, mean arterial pressure and pulse with exercise. Assume that the stroke volume increased from 75 mL/beat to 100 mL/beat. Use this information and the change in pulse with exercise to calculate the change in cardiac output (stroke volume × heart rate) that occurred per minute.• 75 * 92= 6900• 100*92= 9200• 2300 cardiac output/minute

2. Pulse pressure is the difference between systolic pressure (peak pressure during active contraction of the ventricles) and diastolic pressure (the pressure that is maintained even while the left ventricle is relaxing). Describe the change in pulse pressure seen with exercise. Which component of the blood pressure is most responsible for this change?

- The systolic pressure went up by 8 mm Hg while the diastolic pressure went down by 18 mm Hg. The pulse pressure went up by 14 bpm after exercise. The component of the blood pressure that is most responsible is the contraction of the heart got stronger thus making the pressure to go up.

3. A change in pulse pressure can be seen in a variety of medical conditions. What would you expect to happen to the pulse pressure in the following examples?

(a) In atherosclerosis there is a hardening of the arterial walls.

- The Systolic pressure will drop because the aortic valve cannot supply enough pressure.

(b) A damaged aortic valve does not seal properly and allows blood to flow back into the ventricle during diastole.

- Pulse pressure increases when the aortic valve is leaky. This is because systolic pressure increases, the ventricle pumps out more blood so the ventricle gets filled from the atrium as well as by the leak and diastolic pressure falls due to the leak.

4. Normal resting heart rates range from 55−100 beats per minute. What was your/the subject’s resting heart rate? How much did your/the subject’s heart rate increase above resting rate with exercise? What percent increase was this?• Resting heart rate-78• Resting rate with exercise- 92• 92-78=14

5. How does your/the subject’s maximum heart rate compare with other students in your group/class? Is this what you expected?

- Some people’s heart rate increased by a larger percentage than other people. Yes, it is what we expected because not everyone has the same heart rate to begin with.

6. Recovery time has been shown to correlate with degree of physical fitness. How does your/the subject’s recovery rate compare to that of your classmates? Is this what you expected?

- For those people that do not exercise regularly take a longer time to recover while those who exercise regularly don’t take as much time to recover.

7. Congestive heart failure is a condition in which the strength of contraction with each beat may be significantly reduced. For example, the ventricle may pump only half the usual volume of blood with each beat. Would you expect a person with congestive heart failure to have a faster or slower heart rate at rest? With exercise?

- I would expect it to be faster since it is pumping half the blood with each beat with and without exercise.

8. Medications are available which can slow the heart or speed it up. If a patient complains of feeling poorly and has a heart rate of 120 beats per minute, should you administer a medicine to slow the rate?

- Yes because then the patient won’t feel so worn out all the time.