The cardiovascular system consists of the heart, blood vessels, and blood. It functions to transport oxygen, nutrients, hormones, and waste products throughout the body. The heart pumps blood through a double circulatory system - the pulmonary circulation carries blood to the lungs to receive oxygen and release carbon dioxide, while the systemic circulation delivers oxygenated blood and nutrients to tissues and organs and returns deoxygenated blood back to the heart. Blood contains red blood cells, white blood cells, platelets, and plasma to perform these critical circulatory functions.

1. Cardiovascular System Notes

7. Cardiovascular System
components
•Blood vessels
•Heart
•Blood

8. Arteries
• Carry blood away from
the heart.
• Under higher pressure
– smaller tubes.
• Carry oxygenated
blood.
• Surrounded by smooth
muscle.

10. Capillaries
• Tiny tubes
• Run close to every cell in yer body.
• Blood cells have to travel in single file.
• Capillary walls are so thin that oxygen,
CO2 and nutrients can pass through them.
• What’s a bruise?

15. Veins
• Carry blood back to the heart.
• Blood is deoxygenated.
• Lower pressure – larger tubes.
• Veins have one-way valves.
• Contracting muscle squeezes veins,
forcing blood back to heart.

16. Cardiovascular System Functions
Function How?
Carry needed
substances to cells
The blood brings oxygen and
nutrients to the cells
Carry wastes
products away
from cells
The blood takes away carbon
dioxide and other wastes
Carry disease
fighting cells
White blood cells prevent you
from getting sick by killing
bacteria or other things in the
blood

17. The Heart’s Structure
Parts
Atrium - receives the blood that is coming
into the heart. Found at the top of the
heart
Ventricle – pumps the blood out of the
heart. Found at the bottom of the heart
Valve – A flap of tissue that prevents the
blood from moving backwards.

18. How the heart works
First Phase – The heart muscles relax,
blood fills the heart
Second Phase – the heart muscles contract,
the blood is pumped out of the heart

19. Pacemaker
Located in the right atrium, it signals the
heart and tells it when to contract.

21. Circulation Systems
Pulmonary Circulation
From the heart to the
lungs and back to the
heart
Picks up oxygen, drops
off carbon dioxide
Systemic Circulation
From the heart to the
body and back to the
heart
Drops off oxygen and
picks UP carbon
dioxide

22. YOUR BLOOD HAS PARTS
• red blood cells
• white blood cells
• platelets
• plasma

23. RBCs (Red Blood Cells)
• RBCs carry oxygen (O2) AND carbon dioxide
(CO2)
• Each RBC has a protein called hemoglobin,
which binds to the O2 or CO2
• Hemoglobin needs iron to work. If you don’t eat
food with enough iron, you could get dizzy or
faint.

24. RED BLOOD CELLS
Unlike most other cells in the body, red blood cells
have no nuclei. Lacking this large internal structure,
each red blood cell has more room to carry the
oxygen the body needs. But without a nucleus, the
cells cannot divide or synthesize new cellular
components.
After circulating within the body for about 120 days,
a red blood cell will die from aging or damage. But
don't worry — your red bone marrow constantly
manufactures new red blood cells to replace those
that perish - at the rate of 2 million per second!

25. WBCs (White Blood Cells)
• Pathogens – bacteria, viruses, or other
microscopic particles that make you sick.
• If pathogens enter the body, WBCs will engulf
(swallow) and digest them.
• Other WBCs release Antibodies – tags that
stick to pathogens. CLICK HERE TO SEE

26. Platelets
• Platelets – tiny particles that clot your blood.
• If an artery or capillary or vein is broken or
damaged, platelets clump together in the
damaged area, forming a plug that helps save
blood from leaking out.
• Clotting: platelets also release chemicals that
react with proteins in the plasma, starting a
chemical reaction that causes tiny fibers to form
a “net” that stops the bleeding.
• CLICK HERE TO WATCH

27. Plasma
• Plasma – the fluid part of the blood.
• Consists of water, minerals, nutrients, sugars,
proteins and more!

28. Fun Fact – you’ve got a lot of blood
tubes!
If you were to lay out all of the arteries, capillaries and
veins in one adult, end-to-end, they would stretch
about 60,000 miles (100,000 kilometers). What's more,
the capillaries, which are the smallest of the blood
vessels, would make up about 80 percent of this
length.
By comparison, the circumference of the Earth is
about 25,000 miles (40,000 km). That means a
person's blood vessels could wrap around the planet
approximately 2.5 times!

29. Fun Fact – the bigger the slower
Across the animal kingdom, heart rate is inversely related to
body size: In general, the bigger the animal, the slower its resting
heart rate.
An adult human has an average resting heart rate of about 75
beats per minute, the same rate as an adult sheep.
But a blue whale's heart is about the size of a compact car, and
only beats five times per minute. A shrew, on the other hand, has
a heart rate of about 1,000 beats per minute. Hummingbirds
have a heart rate of 1,260 beats per minute, but their hearts slow
to 50 beats per minute at night when they enter a hibernation
state known as torpor.

30. Fun Fact – your heart doesn’t need
your body to beat!
The heart actually can still beat after
being removed from the body.
This eerie pulsing occurs because the
heart generates its own electrical
impulses, which cause it to beat. As long
as the heart continues to receive oxygen,
it will keep going, even if separated from
the rest of the body.

31. Not so Fun Fact – you can have a
“broken heart.”
A condition called stress cardiomyopathy entails a
sudden, temporary weakening of the muscle of the
heart (the myocardium). This results in symptoms
akin to those of a heart attack, including chest pain,
shortness of breath and arm aches.
The condition is also commonly known as "broken
heart syndrome" because it can be caused by an
emotionally stressful event, such as the death of a
loved one or a divorce, breakup or physical
separation from a loved one.