Science - The Circulatory System for Grade 9 kids who are studying the different organ systems in our body.

2. OBJECTIVES
Explains how the circulatory system work
together to transport nutrients. Gases and
other molecules to and from the different
parts of the body.

3. TRIVIA
• Your heart pumps about 5 liters of blood per minute, but it’s only about the size of your fisttrusted source.
• It’s estimated that in a 70-year period, your heart will beat over 2.5 billion times.
• In most adult humans, a normal resting heart rate is between 60 to 100 beats per minute.
• The total length of all of the blood vessels in your body is about 60,000 miles.
• Capillaries are your most numerous blood vessels and also the smallest. Red blood cells often have to
move through the capillaries in single-file.
• Your blood pressure changes throughout the day. It’s lowest when you’re asleep, and it peaks in the middle
of the afternoon.

4. PARTS AND FUNCTIONS

5. 1. BLOOD
•Blood consists of:
•Red blood cells – to carry oxygen
•White blood cells – that make up part of the immune system
•Platelets – needed for clotting
•Plasma – blood cells, nutrients and wastes float in this liquid.

6. 2. HEART
•The heart pumps blood around the body. It sits inside the chest, in
front of the lungs and slightly to the left side. The heart is actually
a double pump made up of four chambers, with the flow of blood
going in one direction due to the presence of the heart valves. The
contractions of the chambers make the sound of heartbeats.

9. 3. THE RIGHT SIDE OF THE HEART
•The right upper chamber ( right atrium) takes in deoxygenated
blood that is loaded with carbon dioxide. The blood is squeezed
down into the right lower chamber (right ventricle) and taken by an
artery to the lungs where the carbon dioxide is replaced with
oxygen.

10. 4. THE LEFT SIDE OF THE HEART
•The oxygenated blood travels back to the heart, this time entering
the left upper chamber (left atrium). It is pumped into the left lower
chamber (left ventricle) and then into the aorta (an artery). The
blood starts its journey around the body once more.

11. BLOOD VESSELS
•Blood vessels have a range of different sizes and
structures, depending on their role in the body.

12. 5. ARTERIES
•Oxygenated blood is pumped from the heart along arteries,
which are muscular. Arteries divide like tree branches until
they are slender. The largest artery is the aorta, which connects
to the heart and picks up oxygenated blood from the left
ventricle. The only artery that picks up deoxygenated blood is
the pulmonary artery, which runs between the heart and lungs.

13. 6. CAPILLARIES
•The arteries eventually divide down into the smallest blood vessel,
the capillary. Capillaries are so small that blood cells can only move
through them one at a time. Oxygen and food nutrients pass from
these capillaries to the cells. Capillaries are also connected to
veins, so wastes from the cells can be transferred to the blood.

14. 7. VEINS
•Veins have one-way valves instead of muscles, to stop blood
from running back the wrong way. Generally, veins carry
deoxygenated blood from the body to the heart, where it can
be sent to the lungs. The exception is the network of
pulmonary veins, which take oxygenated blood from the
lungs to the heart.

15. DISEASES

16. HIGH BLOOD PRESSURE
Blood pressure is the measurement of how much force is used
to pump blood through your arteries. If you have high blood
pressure, also called hypertension, it means the force is higher
than it should be. High blood pressure can damage your heart
and lead to heart disease, stroke, or kidney disease.
There are no symptoms with high blood pressure, which is why
it’s often called “the silent killer.”

17. ATHEROSCLEROSIS AND CORONARY
ARTERY DISEASE
Atherosclerosis, also known as hardening of the arteries, occurs when plaque builds up
on the walls of your arteries and eventually blocks blood flow. Plaque is made of
cholesterol, fat, and calcium.
Coronary artery disease indicates that the plaque buildup in your arteries has caused the
arteries to narrow and harden. Blood clots can further block the arteries.
Coronary artery disease develops over time. You can have it but not be aware of any
symptoms. Other times, it may cause chest pain or the sensation of heaviness in the
chest.

18. HEART ATTACKS
A heart attack occurs when not enough blood reaches your heart. This
can happen due to artery blockage. Heart attacks damage the heart
muscle and are medical emergencies.
Call 911 or have someone else call if you have symptoms such as:
pain in the center or left side of the chest that feels like mild or severe
discomfort, pressure, fullness, or squeezing
pain that radiates from the jaw, shoulder, arm, or across the back,
shortness of breath, sweating, nausea, irregular heart beatun,
consciousness.

19. HEART FAILURE
Sometimes called congestive heart failure, heart failure occurs
when the heart muscle is weakened or damaged. It can no longer
pump the volume of blood needed through the body. Heart failure
normally occurs when you’ve had other heart problems, such as a
heart attack or coronary artery disease.
Early symptoms of heart failure include fatigue, swelling in your
ankles, and increased need to urinate at night. More severe
symptoms include rapid breathing, chest pain, and fainting.

20. STROKES
Strokes often occur when a blood clot blocks an artery
in the brain and reduces the blood supply. They also
can happen when a blood vessel in the brain breaks
open. Both events keep blood and oxygen from
reaching the brain. As a result, parts of the brain are
likely to be damaged.

21. ABDOMINAL AORTIC ANEURISMS
An abdominal aortic aneurism is a bulge in a weakened part of the
aorta. The aorta is the largest blood vessel in your body. It carries
blood from your heart to your abdomen, legs, and pelvis. If the
aorta ruptures, it can cause heavy bleeding that’s life-threatening.
An abdominal aortic aneurism can stay small and never cause
problems. Large and rapidly growing abdominal aortic aneurisms
are at greatest risk of rupturing. These require immediate
attention.

22. PERIPHERAL ARTERY DISEASE
Peripheral artery disease (PAD) is atherosclerosis that occurs in the
extremities, usually in your legs. It reduces blood flow to your legs, as
well as to your heart and brain. If you have PAD, you’re at greater risk of
developing other circulatory system diseases.
Many people have no symptoms with PAD. But if you do, symptoms may
include:
• pain or cramping in the legs, especially when walking
coolness in legs or feet
• sores that don’t heal on the feet or legs
• redness or other changes in skin color

23. WHAT CAN YOU DO TO KEEP
YOUR CIRCULATORY SYSTEM
HEALTHY?

24. •Get your heart pumping. Regular cardiovascular exercise is one
of the best ways to get your heart pumping and to improve
blood flow throughout your body. It’s recommended trusted
source that you aim for 150 minutes of moderate-intensity
cardio exercise per week.

25. •Eat heart-healthy foods. Choose foods like whole grains, fresh fruits and
vegetables, and lean protein, including fish. Try to limit foods that are high in:
•Sodium
•Saturated fats
•Trans fats
•Added sugars
•Cholesterol

26. •Maintain a moderate weight. Carrying more
weight can place more stress on your heart and blood
vessels.

27. Manage stress. High levels of long-term stress
can affect your heart health. Try to manage
stress in healthy ways. Some stress-reducing
options include:
• Exercise
• Meditation
• Breathing techniques
• Yoga

28. •Limit sitting. Sitting still for long periods, such as at a
desk or on a plane, can restrict blood flow. Make a
point to stand up and move around at least once an
hour.

29. •Quit smoking. Smoking increases your risk of
cardiovascular disease. If you’re having difficulty
quitting, talk to your healthcare provider. They can
help you come up with a plan and recommend tools
to help you quit.

30. •See your doctor regularly. Getting regular
checkups can help you and your doctor monitor
your overall health, including your blood pressure,
cholesterol, and any underlying conditions.