The lab prepared will teach you how to measure blood pressure. Learn where systolic and diastolic pressure begins. Next observe venous return, heart rate, and blood pressure in three different scenarios including: normal range, resting rate, and increased exercise.
In the circulatory system lab, students observed how physical activity affects blood pressure and heart rate. With a partner, one student’s pressure was recorded at basal (normal) rate, lying down, and after exercising. Normal blood pressure is systolic 120 and diastolic 80. A normal heart rate is 60 beats per minutes. Systolic pressure is the pressure of blood during contraction and would be considered as the first twitch of the stethoscope. Diastolic pressure is the pressure in the blood vessels in between heartbeats at a relaxation point and would be the last twitch before the needle drops completely on the stethoscope.
These points are considered as lub & dub. Lub or S1 is the first heart beat and the closing of the tricuspid & bicuspid valves. The second heart beat, s2 is dub, the closing of semilunar valves. Blood pressure and heart rate increase after physical activity due to the fact that the body uses more oxygen and releases higher volumes of carbon dioxide. In our experiment the test subject needed more oxygen while exercising. The 25 jumping jacks preformed increased blood pressure and heart rate. If the test was preformed on a different test subject results may change, depending on body mass, weight, height, male or female.
If physical activity increases, then blood pressure and heart rate will rise.
•Stethoscope • Test subject •Watch • Administer •Sphygmomanometer (Blood pressure cuff)
See” Lab 4: The Circulatory System” 2013 eScience Labs, LLC, 10/21/2014.
Table 2: Blood Pressure and Pulse Reading
1. What is systolic pressure?
Systolic blood pressure is the pressure when the heart ventricles contract and pump blood out of the heart. This is the highest pressure in the blood vessels.
2. What is diastolic pressure?
Diastolic pressure is the pressure between heart beats when the heart ventricles are resting and filling with blood. This is the lowest pressure in blood vessels
3. Why is pressure a sensible reading to circulatory health?
Because through pressure, people can determine how much blood are pumped out of the heart in a single contraction. A person with a healthy circulation‘s blood pressure should be at the normal level.
4. Explain the “lub-dub” sounds of the heartbeat?
“Lub-Dub” is the first and second heart sounds that are clearly heard with a stethoscope. These sounds are the closing of the heart valves. •The first heart sound, know as “lub” starts when the ventricles contract. The atrioventricular valves are closed and the blood is pumped out of the heart. The second heart sound, known as “dub”, starts when the ventricles relax. The semilunar valves are closed and the ventricles are filled.
5. Why do blood pressure and heart rate change after exercise?
The muscles in the body need more oxygen during exercise. The heart then pumps more blood to the lungs for gas exchanging. Since the heart needs to contract harder, the blood pressure and heart rate will be increased.
6. How might the results in Table 2 change if someone else performed the activities? Why?
The results in Table 2 would be lower or higher if someone else performed the activities because the sex, height, weight, and health could also affect the results.
7. Why is it important for blood to flow in only one direction?
Every part of human body needs oxygen in order to perform works properly. Oxygen-rich blood supplies oxygen needed to every part of the body and oxygen-poor blood needs to flow to the lungs to exchange gas. If blood flows backward, the body will not get the oxygen it needs to maintain normal homeostasis therefore it will be under a serious threatening.
In this experiment, we saw that the blood pressure and heart rate significant increased after the subject exercised. From table 2, we saw that the blood pressure increased from 120/75 to 140/80 and the pulse increased from 60 beats /minute to 68 beats /minute after exercised. The rate of blood pressure and pulse were lowest when the subject lied down, which only 120/60 mmHg for blood pressure and 56 beats/minute for the pulse. Since the blood pressure and heart rate raised as body movement increased, we concluded that this is a statistically significant result.
Blood pressure measurements generally reflect arterial blood pressure. The high and low points of blood pressure are expressed in millimeters of mercury (mmHg). The normal blood pressure in healthy individual is 120/80(mmHg). Blood pressure is usually measured with the sphygmomanometer (blood pressure cuff) which normally composed of a cuff with an inflatable bladder and a mechanical manometer with a rubber bulb.