BIOLOGY STUDY PACKET
CARDIOVASCULAR SYSTEM
SC.912.L.14.36 AA
Spring 2012
The intent of this packet is to supplement regular classroom instruction, not to replace it. This also
supposes that the students have access to their textbook material, both hard-copy and on-line.
Benchmark:
SC.912.L.14.36 Describe the factors affecting blood flow through the
cardiovascular system.
Benchmark clarification:
Students will identify factors that affect blood flow and/or describe how these
factors affect blood flow through the cardiovascular system.
Content limit:
Items may address factors such as blood pressure, blood volume, resistance,
disease and exercise.
Prior Knowledge:
Students should know information from SC.6.L.14.5, which is to identify and
investigate general functions of body systems and describe ways these systems
interact with each other to maintain homeostasis.
Text book references: Regular Biology, Holt by Stephen Nowicki, Chapter 30
Honors Biology, Pearson by Miller & Levine, Chapter 33.1 & 33.2
Vocabulary:
Artery(ies), veins, capillary(ies), pacemakers, blood pressure (systolic and
diastolic), myocardium, platelets, atherosclerosis, cholesterol, hypertension,
stroke
Background information:
Arteries and Veins structural differences
The structural differences between arteries and veins are all based in their relationship to the
heart. You see, since arteries receive blood from the heart, the blood they receive is under a lot
of pressure. Can you picture how much pressure the arteries near the heart (like the pulmonary
trunk and the aorta) have to withstand every time the ventricles squirt out a load of blood? At
the same time, this pressure helps the blood move through the arteries-- even when the arteries
are running in opposition to gravity (like the common carotid artery running toward the head).
The veins only receive the blood after it has travelled quite far from the heart. The blood
pressure in the veins is thus much less; the blood is certainly much less likely to burst through
walls of the veins than arteries. Also, because the blood pressure is small in the veins, it is not
going to be enough to return all that blood to the heart; in fact, the blood could easily back up
or collect in these vessels, right?
Knowing these facts, you should be able to imagine the following needs of the two types of
blood vessels:
o Arteries: must be able to endure high pressure of blood
o Veins: must be able to prevent blood from backing up
 Must be able to allow some blood to collect without bursting
These are the very conditions that the different structures of arteries and veins reflect
Arteries have thick walls
Arteries and arterioles have thicker walls than veins and venules, respectively. The increased amount
of smooth muscle that is found in arteries gives them extra strength and elasticity to deal with the
surges of blood from the heart
Veins have valves and wider inner diameters
Veins have valves within them to prevent backflow of blood.
Blood is allowed to go toward the heart, but it cannot fall back the other way. These types of valves are
especially important in getting blood back from places like your legs, all the way back to the heart.
When a health professional draws blood from you, they draw blood from your veins. You may have
known that already, but whether or not you knew that, now you should know why...
1. Veins, with their thinner walls and larger diameters are easier to stick with a needle and to
extract blood from.
2. The thinner the vessel, the less the innervation, so the less painful to stick with a needle.
3. Veins have blood under less pressure within them, so when you stick a vein with a needle, blood
will not typically seep out much through your injection site.
4. Veins "store" blood, so much more blood is readily available in your veins.
Heart Disease Facts
America's Heart Disease Burden
In 2008, over 616,000 people died of heart disease. Heart disease caused almost 25% of
deaths—almost one in every four—in the United States.1
Heart disease is the leading cause of death for both men and women. More than half of the
deaths due to heart disease in 2008 were in men.1
Coronary heart disease is the most common type of heart disease. In 2008, 405,309 people died
from coronary heart disease.1
Every year about 785,000 Americans have a first heart attack. Another 470,000 who have
already had one or more heart attacks have another attack.2
In 2010, coronary heart disease alone was projected to cost the United States $108.9 billion.3
This total includes the cost of health care services, medications, and lost productivity.
Deaths Vary by Ethnicity
Heart disease is the leading cause of death for people of most ethnicities in the United States, including
African Americans, Hispanics, and whites. For American Indians or Alaska Natives and Asians or Pacific
Islanders, heart disease is second only to cancer. Below is the percentage of all deaths caused by heart
disease in 2008, listed by ethnicity.1
Race of Ethnic Group
% of Deaths
African Americans
24.4
American Indians or Alaska Natives 17.9
Asians or Pacific Islanders
23.2
Hispanics
20.7
Whites
25.1
All
24.9
Risk Prevention
For people with heart disease, studies have shown that lowering cholesterol and blood pressure
levels can reduce the risk of—
o Dying from heart disease.
o Having a nonfatal heart attack.
o Needing heart bypass surgery or angioplasty.
o For people without heart disease, lowering cholesterol and blood pressure levels can
reduce the risk for developing heart disease.
Early Action is Key
In a 2005 survey, most respondents—92%—recognized chest pain as a symptom of a heart
attack. Only 27% were aware of all major symptoms and knew to call 9-1-1 when someone was
having a heart attack.4
About 47% of sudden cardiac deaths occur outside a hospital. This suggests that many people
with heart disease don't act on early warning signs.5
Americans at Risk
Below is the percentage of U.S. adults with heart disease risk factors in 2005-2008.6
Risk Factor
%
Inactivity
53
Obesity
34
High Blood Pressure 32
Cigarette Smoking 21
High Cholesterol
15
Diabetes
11
In 2003, approximately 37% of adults reported having two or more of the risk factors listed above.7
Source: Center for Disease Control and Prevention
Benefits of Exercise:
Exercise for a Healthy Heart
A sedentary (inactive) lifestyle is one of the top risk factors for heart disease. Fortunately, it's a risk
factor that you can do something about. Regular exercise, especially aerobic exercise, has many
benefits. It can:
Strengthen your heart and cardiovascular system.
Improve your circulation and help your body use oxygen better.
Improve your heart failure symptoms.
Increase energy levels so you can do more activities without becoming tired or short
of breath.
Increase endurance.
Lower blood pressure.
Improve muscle tone and strength.
Improve balance and joint flexibility.
Strengthen bones.
Help reduce body fat and help you reach a healthy weight.
Help reduce stress, tension, anxiety, and depression.
Boost self-image and self-esteem.
Improve sleep.
Make you feel more relaxed and rested.
Make you look fit and feel healthy.
Regular exercise improves the heart because it is a muscle and just like all muscles if you
exercise it regularly it becomes stronger, and a strong healthy heart is probably the single most
important factor in preventing disease - In fact it can literally save your life and you can ask no
more of any muscle than that.
The reason exercise works to keep your heart healthy is because when you train your heart is
required to work harder than normal and therefore pumps more oxygen filled blood throughout
your body. This improves your circulation and helps to keep all of your organs and muscles
healthy.
The result is your heart becomes stronger and therefore less susceptible to disease which is a
great benefit on its own but it gets even better than that because regular exercise will also lower
your resting heart rate meaning that it doesn’t have to work as hard to do its job and just like a
machine the less it has to work the longer it will last.
If that sounds great just consider for a moment that a very fit athlete can achieve a resting heart
rate of 45-50 beats per minute whilst a normal person of the same age will have a resting heart
beat of 70 – 75 beats per minute. As you can see the athlete’s heart only has to do two thirds of
the work of an average persons which helps maintain a healthy heart.
The more research that is done the more scientists are realizing that the worst thing you can do
to for a healthy heart is nothing at all because the fact is, a sedentary life style is a major cause
of heart disease and heart attacks. So when it comes to your heart it is a classic case of use it or
lose it and you only have to look at the statistics of America to confirm this.
The sedentary or inactive life style that has swept the country has led to heart attacks and
coronary disease becoming the number one cause of death and disability in the United States
but the sad thing is it doesn’t have to happen if people would only get of their backsides and
become more active.
For instance, did you know that a good exercise program will reduce your chances of having a
heart attack by as much as 45%? And you also have the other health benefits of exercise to take
into consideration such as the reduced risk of developing diabetes, obesity, high blood pressure
as well as preventing many other horrible diseases.
Stroke Symptoms
By Mayo Clinic staff
Watch for these signs and symptoms if you think you or someone else may be having a stroke. Note
when signs and symptoms begin, because the length of time they have been present may guide
treatment decisions.
Trouble with walking. You may stumble or experience sudden dizziness, loss of balance or loss of
coordination.
Trouble with speaking and understanding. You may experience confusion. You may slur your words or
be unable to find the right words to explain what is happening to you (aphasia). Try to repeat a simple
sentence. If you can't, you may be having a stroke.
Paralysis or numbness on one side of your body or face. You may develop sudden numbness, weakness
or paralysis on one side of your body. Try to raise both your arms over your head at the same time. If
one arm begins to fall, you may be having a stroke. Similarly, one side of your mouth may droop when
you try to smile.
Trouble with seeing in one or both eyes. You may suddenly have blurred or blackened vision, or you
may see double.
Headache. A sudden, severe "bolt out of the blue" headache, which may be accompanied by vomiting,
dizziness or altered consciousness, may indicate you're having a stroke.
Students complete the following:
1.
Students Prepare a Heart Health Pamphlet such as you would find in your doctor’s office
summarizing the different aspects of heart disease and the benefits of exercise. Include pictures
from the internet or magazines to help make your point.
2.
This concept map can be accessed on www.classzone.com Chapter 30, Section 1 Interactive
Review
3.
4.
FCAT Style Questions:
1. Many athletes who are in good condition have heartbeat rates that are substantially slower than the
60 to 80 beats per minute (bpm) considered normal for the rest of us. Former cyclist Lance
Armstrong routinely had a resting heart rate of about 32 bpm. For a non-athlete, a heartbeat rate
this low might be cause for hospitalization, but the rate of blood flow in an athlete's body is not
affected by it. How can an athlete's body function normally with such a low heartbeat rate?
A.
B.
C.
D.
People who are athletes are born with slow heart rates so it is normal for them.
Exercise strengthens the athlete's heart muscle so more blood is pumped with each beat.
An athlete's heart rate is higher than normal while exercising so it averages out to normal.
More capillaries appear in muscle tissue with exercise so blood flow is more efficient.
2. In the human circulatory system, veins have valves but arteries do not. What would be the most
likely result if veins did NOT have valves?
A.
B.
C.
D.
Blood would return to the heart through the arteries.
Blood would have higher pressure after passing through capillaries.
Blood would have difficulty returning to the heart.
Blood would not be able to leave the heart with any force.
3. Arteries not only carry blood away from the heart, they also help keep it moving forward. What
feature of an artery's structure makes it particularly good at doing this?
A.
B.
C.
D.
Their walls are made of layers of stretchy muscle tissue.
They have walls made of rigid, inflexible muscle tissue.
The small pumps in the arterial walls help move blood forward.
The paddle-like valves in the arteries sweep the blood forward.
4. Which of the following would cause the brain to send signals which would cause capillaries in the
calf muscles to dilate while at the same time closing off some of the capillaries in the digestive tract?
A.
B.
C.
D.
eating dinner
going running
standing still
lying down
5. After a man suffered a stroke, he was unable to use his left arm. What happened inside his body
during the stroke that led to his losing the ability to use his left arm?
A.
B.
C.
D.
A blood clot blocked an artery leading into his left arm during the stroke.
Aging capillaries in his left arm collapsed and shut down during the stroke.
A surge of blood into his brain rearranged some neuron connections during the stroke.
Blood flow to a portion of the right side of his brain was cut off during the stroke.
6. When a person has high blood pressure, the walls of their arteries remain stretched abnormally and
become injured. Once an arterial wall is injured like this, what is likely to happen?
A. Deposits of LDL cholesterol and white blood cells will collect at the site of injury resulting in
atherosclerosis.
B. The body will build a new piece of artery to replace the injured section and blood will be
rerouted through it.
C. Cholesterol will be deposited along the inside of the artery narrowing its diameter and lowering
blood pressure.
D. Blood will leak slowly out of the thinning walls of the artery and eventually lower the blood
pressure.
7.
Which of the following might cause the platelets in your blood to form clots?
A.
B.
C.
D.
running a race
sitting for a whole day
eating leafy vegetables
cutting your finger
8. A 20-year-old man decided to jump into a very cold lake. What is the MOST likely way in which his
circulatory system will respond after he jumps into the water?
A. Many of the capillaries in his extremities will shut down so more of his blood will stay in the
warm core of his body.
B. Capillary beds in his leg and arm muscles will get a rush of blood to encourage him to swim to
shore more quickly.
C. The shock of hitting the very cold water will cause a rush of adrenaline which will make his heart
stop beating.
D. He will have difficulty breathing at first but once his lungs warm up he will be able to breathe
more easily.
Teacher Answer Key
Students were given four tasks (assignments), the first was to prepare a pamphlet suitable for their
doctor’s office on heart disease and the benefits of exercise.
Crossword Puzzle Answers
Across:
4.
7.
8.
9.
10.
11.
Down:
arteries
myocardium
cholesterol
pacemakers
platelets
systolic pressure
FCAT Question Answers.
1.
B
2.
C
3.
A
4.
B
5.
D
6.
A
7.
D
8.
A
1.
2.
3.
4.
5.
6.
8.
Diastolic pressure
Veins
Stroke
Atherosclerosis
Blood pressure
Hypertension
Capillaries