The document discusses the circulatory system and its major components. It explains that the circulatory system transports oxygen, nutrients, and wastes throughout the body. The three major parts of the circulatory system are the heart, blood, and blood vessels. The heart pumps blood through the blood vessels to circulate nutrients and oxygen to cells and tissues, and to remove wastes. Blood vessels include arteries, veins, and capillaries that carry blood throughout the body.

2. When a pregnant woman goes to her
first check-up with the doctor, the first
thing the doctor does is to listen to the
baby’s heartbeat. It is the first sign of
life, and it is also the last to stop before
the person passes away – this occur
when the heart rate falls to zero.

3. In the previous lesson, you learned that
the oxygen are transported through
circulatory system. In this lesson you
will find out what are the important
parts in circulatory system and its
functions.

4. 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 neighborhood.

5. Sequentially, the community of cells
sustains the body to stay alive.
Another name for the circulatory
system is the cardiovascular system.

6. 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.

8. What are the three major parts
of the circulatory system and
their roles?

9. Heart
pumps the blood throughout the
body

10. Blood
carries the materials
throughout the body

11. Blood vessel
carries the blood throughout the
body

12. The main types of blood
vessels

13. Arteries
carry oxygenated blood away
from the heart to the cells,
tissues and organs of the body

14. Veins
carry deoxygenated blood to
the heart

15. Capillaries
the smallest blood vessels in the
body, connecting the smallest
arteries to the smallest veins -
the actual site where gases and
nutrients are exchanged

16. Circulation

18. 2. Coronary
Circulation
Movement of
blood
through the
tissues of the
heart

21. Activity 4
Let’s organize

22. Objectives:
- Identify the components of the
circulatory system
- Explain the different types of
circulation

23. Procedure:
Using the given graphic
organizer, fill in the missing
parts, description, and
functions to complete the entire
concept.

25. The Human Heart

26. Do you know how big your
heart is?
Take a look at your fist.

27. The heart is
a hollow
muscle, as
seen in
Figure 7,
which is
just as big
as your fist.

28. It has four chambers
with specific tasks to do:
- two ventricles and
- two atria.

29. The atria are the receiving
chambers of the heart,
accepting blood from the body
(right atrium) and from the
lungs (left atrium).

30. The ventricles are the pumping
chambers, moving blood to the
lungs (right ventricle) and into
the body (left ventricle).

31. The heart has two pumps. Each
pump has two chambers, the
upper and lower chambers. The
upper chamber is the atrium that
receives blood coming in from the
veins. The lower chamber is the
ventricle that forces the blood out
into the arteries.

32. There is a valve between each
atrium and ventricle to prevent
the blood from flowing
backwards. The valves are like
one-way doors that keep the
blood moving in only one
direction.

33. Valves control movement of
blood into the heart
chambers and out to the
aorta and the pulmonary
artery.