Grade 9 Science Module #1 Circulatory System -Definition -Function -Importance

3. The circulatory
system delivers oxygen and
nutrients to cells and takes
away wastes. The heart
pumps oxygenated and
deoxygenated blood on
different sides.
cardiovascular system.

4. Oxygenated Deoxygenated

8. Heart
Blood Vessels
Blood

12. Heart’s Parts and Functions:
1. Left atrium- receives blood full of oxygen from the lungs
and then empties the blood into the left ventricle.
2. Mitral Valve- keeps your blood moving in the right
direction. A leaky valve doesn't close the way it should,
allowing some blood to flow backward into the left
atrium.
3. Left ventricle- is the main chamber of your heart. It is
responsible for pumping oxygen-rich blood into your
aorta.
4. Aortic Valve- It separates the lower left heart chamber
(left ventricle) and the body's main artery (aorta).

13. 5. Aorta- the largest artery in the body. It carries blood
away from your heart to the rest of your body.
6. Superior Vena Cava-It carries blood from the head,
neck, arms, and chest. The inferior vena cava carries
blood from the legs, feet, and organs in the abdomen
and pelvis. The vena cava is the largest vein in the body.
7. Right Atrium- It receives deoxygenated blood from
the systemic circulation. Deoxygenated blood refers
to the blood that has a low oxygen saturation relative
to blood leaving the lungs.

14. 8. Tricuspid Valve-These valve flaps open to let blood flow
from the upper right chamber (right atrium) to the lower
right chamber (right ventricle). The valve flaps then close
tightly to prevent the blood from moving backward.
9. Right Ventricle- the most anterior of the four heart
chambers. It receives deoxygenated blood from the right
atrium (RA) and pumps it into the pulmonary circulation.
10. Pulmonary artery- carries deoxygenated blood from the
right ventricle to the lungs. The blood here passes through
capillaries adjacent to alveoli and becomes oxygenated as
part of the process of respiration.

15. 11. Pulmonary Valve- It's between the lower
right heart chamber (right ventricle) and the
artery that delivers blood to the lungs
(pulmonary artery).
12. Inferior Vena Cava (IVC)- is the largest vein
of the human body. It is located at the posterior
abdominal wall on the right side of the aorta.
The IVC's function is to carry the venous blood
from the lower limbs and abdominopelvic
region to the heart.

16. Four Major Valves in the Heart:
• Mitral Valve- keeps your blood moving in the right direction. A
leaky valve doesn't close the way it should, allowing some blood to
flow backward into the left atrium.
• Aortic Valve- It separates the lower left heart chamber (left
ventricle) and the body's main artery (aorta).
• Tricuspid Valve-These valve flaps open to let blood flow from the
upper right chamber (right atrium) to the lower right chamber
(right ventricle). The valve flaps then close tightly to prevent the
blood from moving backward.
• Pulmonary Valve- It's between the lower right heart chamber (right
ventricle) and the artery that delivers blood to the lungs
(pulmonary artery).

17. Pulmonary Valve
Upper Chamber
Lower Chamber
Aortic Valve

20. What disease is known to be
cancer of the blood?

21. Lungs Left Atrium Mitral Valve Left Ventricle
Veins Cells (Capillaries) Aorta
Right Atrium Tricuspid Valve Right Ventricle

26. Importance of Circulatory System:
•The circulatory system is the life support structure that
nourishes your cells with nutrients from the food you eat
and oxygen from the air you breathe. It can be compared to
a complex arrangement of highways, avenues and lanes
connecting all the cells together into a neighbourhood.
Sequentially, the community of cells sustains the body to
stay alive.
•The circulatory system functions with other body systems
to deliver different materials in the body. It circulates vital
elements such as oxygen and nutrients. At the same time, it
also transports wastes away from the body.