Anatomy and physiology labs ||

Experiment 3 Blood Pressure Experiment Inventory

Materials Sphygmomanometer (Blood Pressure Cuff)

Stethoscope

*Stopwatch/Timer Note: You must provide the materials listed in *red.

EXPERIMENT 3: BLOOD PRESSURE Blood pressure provides information about the heart and circulatory system. Blood pressure increases, specifically throughout the arterioles, when the ventricles contract. Arterial blood pressure is directly dependent on the amount of blood pumped by the heart each minute and the resistance to the flow of blood through arterioles. Thus, blood pressure is an important indicator of circulatory system health. The following experiment can be performed by yourself or with a partner to observe how physical activity affects heart rate and blood pressure.

Note: Consult a physician if you are concerned about the safety of this experiment or if you have any health concerns.

PROCEDURE 1. To take a pulse, place the pad of your forefinger on your radial artery, and count the number of beats felt in 15 seconds.

2. Multiply this number by four to calculate the beats per minute.

Note: The pulse can be felt on any artery close to the surface and compressed over a bone or other firm tissue. A stethoscope can also be used to listen to the heartbeat by placing the chestpiece on the thorax, just medial to the left nipple.

3. Wrap the blood pressure cuff around your upper arm so that the bottom of the cuff is above the elbow.

4. Sit comfortably with one arm elevated to heart level.

5. Place the earpieces of the stethoscope in your ear, and place the diaphragm on the brachial artery (Figure 5).

6. Inflate the cuff by closing the valve on the bulb and squeezing the bulb repeatedly until blood flow stops. This will likely occur at approximately 130 – 180 mmHg.

7. Crack the silver valve on the bulb to slowly release the cuff pressure.

8. Listen with the stethoscope for the return of blood flow into the forearms (Korotkoff sounds).

9. Systolic pressure is the pressure at which the first sound of blood flow is heard after pressure is released. You may also see a tapping of the needle on the pressure gauge that corresponds with the pulse.

10. As the pressure continues to decrease, blood flow returns to normal, and the Korotkoff sounds can no longer be heard. The pressure at which this transition occurs is diastolic pressure.

11. Record your blood pressure measurement (systolic/diastolic) and heart rate in Table 2.

12. Lie down for 15 minutes. At the end of this time, record your blood pressure and pulse. Be sure to remain laying down while taking your measurement. Record your results in Table 2.

13. Record your blood pressure and pulse after doing 25 jumping jacks in Table 2.

Figure 5: Diaphragm place- ment.

© eScience Labs, 2016

Data SheetExperiment 3 Data Sheet Table 2: Blood Pressure and Pulse Readings

Activity Blood Pressure (Systolic/Diastolic; mmHg) Pulse

(beats/minute)

Basal (Normal)

Lying Down

After Exercise

© eScience Labs, 2016