Download The Body`s Transport System 1

The Body’s Transport System
Cardiovascular system
• Heart
• Blood Vessels
– Arteries
– Veins
– Capillaries
• Blood
Cardiovascular System
• The overall function of the circulatory
system is to transport materials
throughout the body toward and away
from particular target organs and tissues.
• Carries need materials to cells and removes
waste from cells.
How the heart works
• Keeps blood moving through the blood
vessels.
• Large organ composed of Cardiac muscle
• Two phases
1. The heart muscle relaxes and fills with blood.
2. The heart then contracts and pumps blood
forward.
The heart
• At REST, the heart pumps about 5 QUARTS of
blood a minute.
• During EXTREME EXERTION (exercise) it can
pump 40 quarts a minute.
• Average resting heart beat
- 60-100 beats per min.
- 100-170 beats per min
The heart
Heart Structure
• Four chambers
– Two upper (Atrium)
• Right Atrium
• Left Atrium
– Two lower (Ventricles)
• Right Ventricle
• Left Ventricle
- Valves separate
Chambers and keep
Blood from flowing
Backwards.
Key terms
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Pacemaker
Atrium
Valve
ventricle
Two Loops
• Pattern of blood flow.
• In the 1st loop, blood travels
From the heart to the lungs
And then back to the heart.
- In the 2nd loop, blood is
Pumped from the heart
Throughout the body and then
Returns again to the heart.
Arteries
- Carries blood away from the heart.
– Large
– Thick-walled, Muscular
– Elastic
– Oxygenated blood
•
Exception Pulmonary Artery
– Carried under great pressure
– Steady pulsating
Arterioles: smaller vessels, enter tissue
Arteries
Capillaries
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Smallest vessel
Microscopic
Walls one cell thick
Nutrients and gases diffuse here
Veins
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–
Carry blood to the heart.
Carries blood that contains waste and CO2
•
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Exception pulmonary vein
Blood not under much pressure
Valves to prevent much gravity pull
Blood Pressure
• The force that blood pushes against the walls
of blood vessels.