AP Biology Lab 10: Physiology of the Circulatory System
Mrs. Dietz
Laura Kelly
Rachel Butch
Pd. 7
3-20-11
Introduction:
The lab explores the effects of position, activity, and temperature on heart
rate and blood pressure. Also explored is the circulatory systems effect on metabolic
activity.
The objective of the first part exercise 10A was to learn to measure the heart
rate and blood pressure. The objective of lab exercise 10B is to learn to explain
blood pressure and heart rate’s changes due to change in position. From this
information, the fitness index of a volunteer would be determined. Also, exercise’s
effects on heart rate have to be understood. In lab exercise 10C, the objective was to
analyze temperatures effects on heart rate of ectotherms.
These objectives all contribute to the purpose of the lab: to explore the
circulatory systems response to different factors as listed above.
Questions:
Does physical training affect the results of the heart rate’s response to physical
activity?; if the volunteer is physically fit, their smooth and cardiac muscle have
more endurance than someone’s who is not in shape and will produce less dramatic
results.
Methods and Procedure:
10A:
Lab exercise A focused on taking the blood pressure of a subject at rest. The
sphygmomanometer was wrapped snugly around the upper arm of the subject. The
stethoscope was placed on the underside of the arm below the elbow joint to listen
for the blood flow. Air was then pumped into the sphygmomanometer to 180mmHg.
The air was then slowly released and the pressures at which the systolic and
diastolic pressures were heard were recorded. This process was repeated 2 times
and the average was taken of all three.
10B:
Exercise 10B measured the effects of changes in physical demand on the
response of the cardiovascular system through a series of fitness tests. In the first
fitness test, the human volunteer reclined on a lab bench for five minutes, and then
her systolic and diastolic pressures were measured with the sphygmomanometer
and recorded. The subject remained reclining for two more minutes. Then she
stood up and immediately her systolic and diastolic pressures were again taken.
The changes in systolic and diastolic pressure were next calculated by subtracting
the standing measurements from the reclining measurements. Fitness points were
assigned based on Table 10.2.
In the second fitness test, the subject had been standing for two minutes
following test one when her pulse was take. In order to take her pulse, the number
of beats per 30 seconds were counted and multiplied by two to find out the number
of beats per minute. The pulse, in beats per minute, were then recorded in the data
table.
The third fitness test involved the volunteer again reclining for five minutes.
Her resting pulse was determined using the same technique as in exercise B, and
recorded.
Test four had the subject stand after having reclined for five minutes in the
previous test, and immediately her pulse was taken by counting the number of beats
over thirty seconds and multiplying it by two to determine the pulse in beats per
minute. Next, the reclining pulse rate from test three was subtracted from the
standing pulse rate from the current test four. Fitness points were assigned based
on this value and on Table 10.5.
The fifth and final test involved endurance. The volunteer placed her right
foot on a chair, and raised her body so that her left foot met her right foot on the
chair. Then her left foot was returned to the original position on the ground while
her right foot remained on the chair. This exercise was repeated five times, with
three subjects allowed for each rep. Immediately after the exercise, the subject’s
pulse was measured for fifteen seconds, and then again for fifteen more seconds.
These values were multiplied by four to determine the number of beats per minute
of her heart rate right after exercise. The pulse was continually taken for sixty
seconds, 90 seconds, and 120 seconds after the exercises were completed, and each
of these measurements was multiplied by two to determine the pulse in beats per
minute. After it was observed the amount of time it took for the subject’s heart rate
to return to the standing rate from test 2, fitness points were assigned for this
information based on Table 10.6. Finally, in order to calculate the pulse rate
increase, the normal standing pulse rate was subtracted from the pulse rate within
fifteen seconds after exercise. Fitness points were assigned for the pulse rate
increase based on Table 10.7.
Exercise 10C:
Followed Pearson School “Lab Bench” online lab activity.
Results/Charts and Graphs:
The main findings of the lab were that the less physically fit a person is, the
greater the difference is between his or her standing and reclining blood pressures
and cardiac rates. Also, it was determined that the longer it takes to recover
standing cardiac rate after exercise, and the greater the difference between the
cardiac rate while standing and immediately after exercising, the lower the level of
physical fitness. Another result was that the higher the temperature surrounding an
ectotherm, the greater the heart rate.
Measurement
Systolic
Dastolic
Blood Pressure Data
1
2
90
106
60
70
3
100
50
Average
98.67
60
In the table containing Blood Pressure Data, it is shown that the average
systolic pressure for the standing subject whose blood pressure was measured with
the sphygmomanometer was 98.67 mmHg, and that the average diastolic pressure
was 60 mmHg.
Fitness Data
Test 1. Change in systolic pressure from reclining to standing.
Test 2. Standing pulse rate.
Test 3. Reclining pulse rate.
Test 4. Baroreceptor reflex. Pulse rate increase on standing.
Test 5. Step Test.
Retiurn of pluse to standing rate after excerise
Pulse rate increase immediately after exercise.
Measurement
10 mmHg
78 beats/min
42 beats/min
10 beats/min
Points
3
3
3
3
60 seconds
50 beats/min
3
The table of Fitness Data contains results from each of the five fitness test
performed during the lab, both the measurements of either cardiac rate or blood
pressure, and the fitness points. For test 1, the subject’s blood pressure increased
by 10 mmHg from when she was reclining to when she immediately stood. This
measurement was assigned 3 fitness points. In test 2, the subject’s standing pulse or
cardiac rate was 78 beats per minute, which was awarded three fitness points. In
Test 3, her reclining pulse rate was 42 beats per minute, which also earned three
fitness points. Through test 4, it was found that the increase of the subject’s pulse
rate from reclining to standing was ten beats per minute, which is equivalent to
three fitness points. For the fifth and final test, the subject’s pulse rate took sixty
seconds to return to standing rate immediately after exercise, and therefore the
subject earned three fitness points. The increase of her pulse rate from standing to
immediately after exercise was 50 beats per minute, for which she received -1
fitness points. The subject’s fitness points added up to 14, earning a relative cardiac
fitness level of “Good”. In this table it is clear that there is a relationship between
fitness and the differences in heart rate while at varying positions or levels of
physical activity.
Table 10.8: Temperature and Heart Rate Data
Temperature (°C)
Heart Rate (beats/min)
10°
36
20°
66
30°
108
Reading
1
2
3
The data in Table 10.8 shows a relationship between temperature and the
Daphnia’s heart rate: the greater the temperature, the faster the heart rate. For
example, at 10 degrees Celcius, the heart rate was 36 beats per minute, while at 30
degrees Celcius the heart rate was at 108 beats per minute.
The data from Table 10.8 is further represented by graph 10.1.
Heart Rate beats/min
Graph 10.1 Heart Rate beats/min
vs. Temperature
120
100
80
60
Series1
40
20
0
1
2
3
4
5
Temperature (Degrees Celciusx10)
6
excel created points 4, 5, and 6 .we do not know how to remove them.
Also the graph still needs other touchup work
Conclusion/Discussion:
The findings of AP Biology Lab 10 show that body conditions have a large
influence on the heart and circulatory system. Exercise 10A’s purpose was to learn
how to use a sphygmomanometer and establish a baseline with which to compare
future tests. In Exercise 10B, the effects of body position on blood pressure were
observed. Blood pressure of the volunteer was higher than that of the volunteer
while lying down because of the effort of the heart to pump blood against gravity.
While standing, more force must be exerted on the blood traveling from the lower
extremities to movie it up to the heart. In Test 4 of Exercise 10B, the Baroreceptor
reflex was observed. The baroreceptor is a mechanism that allows the body to
remain in equilibrium through a negative feedback loop. When the baroreceptor’s
location is distended, nerves send impulses to the heart to regulate its beats per
minute and therefore controlling blood pressure. This process can also work in the
inverse to lower blood pressure. As expected, upon standing up the subject’s blood
pressure increased drastically. This is explained because while lying down, the
blood pressure required to pump blood throughout the body was very low.
However, upon standing that pressure requirement immediately increased. The
baroreceptor sensed the need for a higher blood pressure and as a result, heart rate
increased. Exercise 10C explored temperature’s effect on the ectotherm Daphnia.
The online lab showed the heart rate of this flea in different temperatures. The
lower the temperature, the lower the heart rate. This can be applied to all
organisms. While at room temperature or slightly warmer, enzymes that work in
metabolic processes within an organisms cell become more effective and when
temperature drops, the metabolic process slows and less blood is necessary to bring
nutrients and carry away products (in addition, the cardiac muscle cells metabolic
processes also slow). These effects are most noticeable in ectotherms because they
are reliant on their environments to control their body temperatures while
endotherms are not. Ectotherms, however are not completely at the mercy of the
elements for they have developed several physiologic behaviors to allow them to
maintain a healthy body temperature. Sources of error for AP Biology Lab 10 were
human error in counting accurately and recording time. It was impossible s to be
exact. Also, the Step Test for endurance’s results were not consistent with the rest of
the tests; the fitness scores for all other tests were very high and for the endurance
test the score was very low. Nothing comes to mind as to what can improve this lab
under normal means. Physical training does seem to have an effect on heart rate and
pressure. Both lab members are competitive athletes and the group scored a “good”
in overall fitness. The result of the endurance test, however is inconsistent with this
claim because both lab members scored poorly. (which doesn’t make sense because
we are both distance competitors.)
Answers:
10A-10B
1. When standing, the heart must pump harder in order to fight gravity and be
able to pump blood back from the far reaches of the body back to the center.
When lying down, gravity is not a factor because the whole body is on the
same plane.
2. High blood pressure puts a strain on blood vessels and cardiac muscle. This
strain can lead to weaknesses in the vessels making strokes a risk. High blood
pressure can also cause various types of heart disease.
3. An athletes cardiac and smooth muscle is well developed to deal with
increased blood pressure through training. The muscle has more endurance
from athletic training than that of a person who is not physically fit and can
more efficiently pump blood through the body .
4. Nicotine found in cigarettes caused decreased oxygen levels in the blood,
requiring the heart to pump faster. Nicotine also causes blood vessels to
constrict by triggering the production of epinephrine. Smoking has also been
observed to cause an increase in blood clots in users. Pressure will rise
behind these clots causing higher blood pressure.
10C
1. Metabolic rate increases with temperature because the enzymes that take
part in cellular reactions are more effective in warm climates. When the rate
increases, the heart must pump faster to deliver and remove substances from
cells.
2. An endothermic organism would display different means of thermo
regulation such as shivering or panting. The heart rate would also show less
dramatic results because the body’s temperature would show little change.
3. Endothermic animas must move to an area that will bring its body
temperature to a desirable level. When they are in need of energy, they will
bask in the sun or move to a warmer area. When too hot, endothermic
animals will move to areas of shade to allow their body temperature to
lower. Bees will band together to create a living sheet that helps to insulate
the nest in cold weather. Likewise, they will also beat their wings in a joined
effort to cool the nest in hot weather.