1. 2.3 The Circulatory and Respiratory Systems
The circulatory system consists of the heart, arteries, capillaries, and veins.
Your heart is a pump that pushes approximately 4 L of blood through your body every minute.
The main purpose of the respiratory system is to exchange gases.
The main organ of the respiratory system are the lungs.
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2. Taking a Closer Look at the Heart
The heart pumps blood throughout the body.
The heart has four chambers:
Left atrium
Blood arrives from your lungs
Right atrium
Blood arrives from your body
Left ventricle
Pumps blood to your body
Right ventricle
Pumps blood to your lungs
Between each of these chambers is a valve.
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3. The Circulatory System
The circulatory system moves blood throughout the body.
There are three types of blood vessels:
Arteries
Carry oxygenated blood away from your heart
Capillaries are tiny blood vessels
Responsible for transfer of oxygen and nutrients into the body cells and collecting waste from the cells.
Veins
Blood containing waste products returning to the heart.
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4. The Circulatory System
Starting with the right atrium, try placing the following structures in the correct order that blood flows through the body.
Left ventricle Body
Right atrium Left atrium
Lungs Right ventricle
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5. The Components of Blood
About 55% of blood is a liquid called plasma.
Contains proteins, minerals, and other substances.
Red blood cells carry oxygen from the lungs to the cells.
White blood cells fight infection.
Platelets are important for clotting blood.
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6. The Respiratory System
The respiratory system moves oxygen into your body and carbon dioxide out of your body.
When you inhale, air is filtered by tiny hairs called cilia.
Air passes through your larynx and continues down your trachea towards your lungs.
At the base of the trachea are two tubes called bronchi.
Bronchi branch into smaller air tubes called bronchioles.
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7. Gas Exchange in the Alveoli
There are millions of alveoli at the ends of the bronchioles, and this is where gas exchange takes place.
Oxygen and carbon dioxide move back and forth between the alveoli and the surrounding blood vessels.
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8. Smoking Smoking may cause both respiratory disease and heart disease.
Respiratory diseases could include emphysema and lung cancer.
Emphysema causes the alveoli walls to lose their elasticity. This may make breathing very difficult.
Smoking also destroys the cilia lining your respiratory system.
Take the Section 2.3 Quiz
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