1. The Circulatory System
Your Body's Transportation
System

2. The heart The blood vessels The blood The Circulatory System
Consists of Three Parts:
The heart
The blood vessels
The blood

3. The Functions of the System
Carries needed materials to the cells
Carries waste products away from the cells
Helps the body fight diseases

4. The Heart
The heart is a hollow muscular organ, about the size of your fist, that is located between your two lungs .
The heart’s function is to pump blood throughout the body.

5. The Heart is actually two separate pumps.
The right side receives blood from the body and pumps it to the lungs.
The left side receives blood from the lungs and pumps it to the body.

6. Each side of the heart is composed of an upper and a lower chamber.
The atrium (upper chamber) receives blood.
The ventricles (lower chamber) pump the blood.
Valves located in the heart keep the blood flowing in one direction.

7. Protection for the Heart
The heart is protected by the skeleton’s sternum and rib cage.
The heart is enclosed by a protective tissue called the pericardium.

8. The Blood Vessels
The human circulatory system is a closed system, the blood is enclosed in vessels.
There are three types of blood vessels: arteries, capillaries, and veins.

9. The Arteries Arteries carry blood away from the heart.
Because the force of the blood leaving the heart is very strong, the walls of the artery are thick and muscular.
Pulse is the expanding and relaxing of the artery walls caused by the blood being force out of the ventricles.

10. Capillaries The capillaries are the smallest blood vessels.
The capillaries are the sites where materials are exchanged with the cells.
Because of this the walls of the capillaries are very thin.

11. Veins Veins carry blood back to the heart.
Because the blood is now moving more slowly, the veins have valves inside to prevent the blood from going backwards.

12. Relationship of Blood Vessels
Blood leaving the heart
enters the arteries. It is
then carried to the
capillaries, where
materials are dropped off
or picked up. Next it travels to the veins for its return trip
to the heart. In-between leaving the heart and returning,
the blood is carried to various cells and organs of the
body by the blood vessels.

13. Blood Pressure
Pressure is the force something exerts over a given area.
Blood exerts a pressure, called blood pressure, on the walls of the blood vessels.
Blood pressure is caused by the force with which the ventricles contract.
The farther away from the contracting ventricle the blood moves, the lower the pressure it exerts, therefore veins have the lowest pressure.

14. Blood is made up of four parts or components: Plasma Red Blood Cells
The Blood
Blood is made up of four parts or components:
Plasma
Red Blood Cells
White Blood Cells
Platelets

15. Plasma Plasma is the liquid part of the blood.
It makes up about 55% of your blood.
90% of the plasma is water, the other 10% is dissolved materials.
Dissolved nutrients, hormones, carbon dioxide, and waste are carried by the plasma
Plasma
Blood Cells

16. Red Blood Cells
Red Blood cells take up and deliver oxygen to the cells.
They are made mostly of hemoglobin, an iron rich protein that chemically binds with the oxygen.
Red blood cells do not have a nucleus, therefore, they only live about 120 days.
Your bone marrow produces new red blood cells.

17. White Blood Cells
White blood cells are the body’s disease fighters.
They are also produced in the bone marrow.
They are larger than red blood cells and have a nucleus, but there are fewer of them in the blood.

18. Platelets
Platelets are cell fragments that are important in clotting blood.
Platelets gather at the site of a wound and release chemicals, eventually forming fibrin, which traps blood cells and forms a clot.

19. Conclusion
Without the circulatory system multi-cellular animals would not be able to maintain life.
It is necessary so that all the cells of the body will receive the required nutrients and oxygen and not die due to the poisons in their waste.

20. Pictures were obtained from the following sites:
Classroom Clipart at
Google Image Search at