The circulatory system uses the heart, blood vessels, and blood to transport nutrients, oxygen, carbon dioxide, wastes, hormones, and blood cells throughout the body. Deoxygenated blood returns to the right atrium via veins and is pumped to the lungs for oxygenation before entering the left atrium and being distributed to tissues by arteries and capillaries, where gas and nutrient exchange occurs. Cardiovascular diseases like atherosclerosis, hypertension, and heart failure can result from risk factors like smoking, obesity, and sedentary lifestyle.

1. The Circulatory System
Chapter 3 Section 1

2. How is your circulatory system like the
plumbing in a house?

5. Materials move through your
body via the….
heart, blood vessels, and
blood
CIRCULATORY SYSTEM

6. Moving…
Blood moves oxygen and
nutrients to cells.
Blood carries carbon dioxide and
other wastes away from the cells.
Movement of materials into and
out of your cells occurs by
diffusion and active transport.

7. Diffusion and Active Transport

8. the heart

10. The flow of blood through the heart
to the lungs and back to the heart.
Pulmonary Circulation

11. 1. Blood, high in
CO2 and low in O2
returns from the
body and travels
to the heart.
It enters the right
atrium through the
superior and
inferior vena cava.
Pulmonary Circulation

12. 2. The right atrium
contracts and
blood enters the
right ventricle. The
ventricle then
contracts and
sends blood to the
lungs through the
pulmonary artery.
Pulmonary Circulation

13. Why are the
pulmonary arteries
special?
They are the only
artery that carries
blood that is low in
oxygen.
Pulmonary Circulation

14. 3. Oxygen rich
blood, from the
lungs, enters the
heart through the
pulmonary vein
and into the left
atrium.
Pulmonary Circulation

15. What makes
pulmonary veins
special?
They are the only
vein that carries
oxygen rich blood.
Pulmonary Circulation

16. 4. The left atrium
contracts and
forces the blood
into the left
ventricle. Once
that contracts,
blood flows out of
the heart and into
the aorta.
Pulmonary Circulation

17. Pulmonary Circulation
1. Blood, high in CO2 and low in
O2 returns from the body and
travels to the heart.
It enters the right atrium through
the superior and inferior vena
cava.
3. Oxygen rich blood, from the
lungs, enters the heart through
the pulmonary vein and into
the left atrium. What makes
pulmonary veins special? They
are the only vein that carries
oxygen rich blood.
2. The right atrium contracts and
blood enters the right ventricle.
The ventricle then contracts
and sends blood to the lungs
through the pulmonary artery.
Why are the pulmonary arteries
special?
They are the only artery that
carries blood that is low in
oxygen.
4. The left atrium contracts and
forces the blood into the left
ventricle. Once that contracts,
blood flows out of the heart
and into the aorta.

18. Blood moves through your body (except
your heart and lungs) by systemic
circulation.
Oxygen-rich blood flows from your heart
through arteries. They carry nutrients and
oxygen to your body cells.
Carbon dioxide and wastes are picked up
by the blood and return, through your veins.
Systemic Circulation

20. Blood Vessels
•Arteries
•Veins
•Capillaries

21. Are you ready for a mind
boggling fact??
If you were to take all of your blood
vessels and lay them out, they would
cover a distance of...
97,000 kilometer
That’s more than 2 times
around the earth!
21

22. Arteries
Blood vessels that carry
blood away from the heart.
Have thick, elastic walls
made of connective tissue,
smooth muscle
Each ventricle of the heart is
attached to an artery.
The right ventricle is
attached to the pulmonary
artery.
The left ventricle is attached
to the aorta.

23. Arteries

24. Veins
Blood vessels that carry blood back to the heart
Veins have one way valves that keep blood
moving towards the heart
Blood flow is helped by your skeletal muscles.
When they contract, the veins are squeezed and
move blood toward the heart

25. Veins
Two major veins return blood
to the heart.
Superior vena cava returns
blood from your head and
neck.
Inferior vena cava returns
blood from your abdomen
and lower body.

26. Veins

27. Capillaries
Arteries and veins are connected by
capillaries.
The walls of capillaries are only one cell
thick
Nutrient and oxygen diffuse into body cells
through the thin capillary walls.
Wastes materials and carbon dioxide
diffuse from body cells into the capillaries.

28. Arteries Veins Capillaries
Carries blood away from heart Carries blood to the heart Connects arteries to veins
Have thick, elastic walls
made of connective tissue,
smooth muscle
Walls consist of three layers of
tissues that are thinner and less
elastic than arteries.
The walls of capillaries
are only one cell thick
Have relatively narrow
lumens compared to veins
have relatively wide lumens
Have relatively more
muscle/elastic tissue
Have relatively less muscle/
elastic tissue
Transports blood under
higher pressure (than veins)
Transports blood under lower
pressure (than arteries)
Do not have valves
Have valves to prevent blood
flowing in the wrong direction
0.1-10mm 5mm 0.02mm

31. circulatory system

32. Blood Pressure
Blood Pressure - the force of blood on the wall of the
blood vessels
Is blood pressure highest in arteries or veins?
Arteries
Systolic pressure - pressure caused when the ventricles
contract and blood is pushed out of the heart
Diastolic pressure - pressure that occurs when the
ventricles fill with blood just before they contract again.

33. Atherosclerosis
Fatty deposits build up on
arterial walls and cause
the arteries to harden and
narrow.
Atherosclerosis is the usual
cause of heart attacks and
strokes.
What can lead to this
disease?
High Blood Pressure
High levels of cholesterol
Smoking
High levels of sugar in
the blood
Cardiovascular Disease

34. Cardiovascular Disease
Hypertension or High Blood Pressure
The higher the pressure the harder the heart has
to pump. Hypertension can lead to damaged
organs, kidney failure, aneurysm, heart failure,
stroke, or heart attack.
The causes of hypertension are:
Smoking
Obesity
Diabetes
Sedentary lifestyle
Lack of physical activity

36. Cardiovascular Disease
Heart Failure
The heart cannot pump blood efficiently.
It might be cause by a weakened heart muscle
or heart valves not working properly.

37. Preventing Cardiovascular
Disease
Ways to prevent cardiovascular disease
Regular check ups
A healthy diet – choosing foods low in salt, sugar,
cholesterol and saturated fats
Exercise
Not smoking