The circulatory system consists of the heart, blood vessels, and blood. The heart pumps oxygen-rich blood received from the lungs through the arteries to the body's tissues, and deoxygenated blood returns to the heart via veins to be re-oxygenated in the lungs. The circulatory system transports nutrients, gases, hormones, and waste products throughout the body and helps fight infections through white blood cells.

1. Parts and Functions of the
Circulatory System

2. The Circulatory System
• known as the
body’s transport
system
• MAIN FUNCTIONS:
deliver food and
oxygen to the cells
Pick up the cells
waste materials and
carbon dioxide

3. The Circulatory System
• consists of the
blood, the blood
vessels, and the
heart

4. Human Blood
• consists of the
liquid part,
plasma, and the
solid
components,
blood cells

5. Functions of the blood:
1. Transports gases, wastes
products, and hormones.
2. Maintains water balance and pH
3. Carries platelets for clotting
4. Destroys foreign materials
5. Distributes antibodies for immunity
6. Regulates body temperature

6. PLASMA
• it is the clear, yellowish
portion of the blood.
• transports blood cells
particularly red blood
cells
• carries food to the cells
and picks up waste
materials
• contains antibodies
that protect your body
from infection

7. Erythrocytes (red blood cells)
• most abundant
type of blood cells
• carry oxygen to all
cells of the body
and collect
carbon dioxide for
disposal
• rich in hemoglobin

8. Erythrocytes (red blood cells)
• red blood cells are produced in
the bone marrow of long bones
• Red blood cells can live for only
three (3) months, they are
degraded by the spleen and iron
is returned to the bone marrow
where new red blood cells will be
formed.

10. Leucocytes (white blood cells)
• are colorless and do not
contain hemoglobin
• The main function is to
protect the body against
infection.
• can live for many months
or years
• are produced in the
bone marrow

11. Different Types of Leucocytes
Types of
Leucocyte
Function Picture
Neutrophil targets
bacteria and
fungi
Eusinophil Targets large
parasites and
modulates
allergic
inflammatory
responses.

12. Different Types of Leucocytes
Types of
Leucocyte
Function Picture
Basophil Releases histamines,
w/c are substance for
inflammatory
responses
Lymphocyte two types: B-cells(
release antibodies) and T-
cells(undergo
phagocytosis or the
process wherein a cell
engulf a foreign body)

13. Different Types of Leucocytes
Types of
Leucocyte
Function Picture
Monocyte Differentiates into
macrophages, w/c
can also perform
phagocytosis
BLOOD CELLS

14. BLOOD VESSELS
• are the transport “highways”
of the blood
Three Major Types of Blood
Vessels:
Arteries
Veins
Capillaries

15. a. Artery
• carries oxygen-rich
blood away from
the heart and into
the organs of the
body
• has very thick walls
that are elastic and
durable

16. a. Artery
• The largest artery
is the aorta.
• Arterioles are the
smallest arteries.
• The only artery
that carries
oxygen-poor
blood is the
pulmonary artery..

17. b. Capillary
• Smallest type of blood
vessels
• Its thin walls allow the
exchange of
important substances
between the blood
and the tissues
through diffusion

18. b. Capillary
• Exchange of gases
(C𝑂2and 𝑂2) and other
delivery of important
nutrients to cells
happen along
capillary walls.

19. b. Vein
• The largest vein in the human body is the
vena cava.
• The only vein that carries oxygen-rich
blood is the pulmonary vein.
• This vessel carries
deoxygenated blood
toward the heart.
• Veins are thinner than
arteries.

20. • The heart is a hollow
muscular organ that
pumps blood
throughout the body.
• It is composed of
primarily of cardiac
muscles and some
connective tissues.
• The pericardium, a
connective tissue,
encloses the heart.
Heart

21. FOUR CHAMBERS
• The heart is divided
into FOUR
CHAMBERS.
The two upper
chambers are
called the atria and
the two lower
chambers are
called the
ventricles.

22. • The rhythmic beat of the heart is
maintained by a specialized system
of nerves.
• The beat is initiated by the sinoatrial
node (SA node) or the pacemaker.

23. • The signal from
the SA node
travels to the
atrioventricular
node(AV node) ,
which is then sent
to the Purkinje
fibers.

25. • How does the
blood flow
through the
heart?

26. Flow of Blood in the Heart
• It is in the right
atrium where
oxygen-poor
blood, from all
parts of the body,
enters through two
large blood vessels
called the vena
cavae.

27. Flow of Blood in the Heart
• Blood from the
upper part of the
body is collected
by the superior
vena cava while
the inferior vena
cava collects
blood from the
lower part of the
body.

28. Flow of Blood in the Heart
• The heart relaxes
and the pressure
causes the right
atrium to fill up, in
between beats.
The right atrium
contracts and
blood is pushed
into the right
ventricle through
the tricuspid valve.

29. Flow of Blood in the Heart
• The heart muscle
again contracts
and blood flows
out of the right
ventricle to the
lungs passing
through the
pulmonary
artery.

30. Flow of Blood in the Heart
• In the lungs,
blood gives off
its carbon
dioxide load and
takes in oxygen.
• After the
exchange of
gases, blood is
oxygen-rich.

31. Flow of Blood in the Heart
• Oxygen-rich blood
flows back to the
heart passing
through the
pulmonary veins.
• Contraction of the
heart muscle
pushes it through
the bicuspid valve
to the left
ventricle.

32. Flow of Blood in the Heart
• From the left
ventricle, blood
flows to all parts
of the body
passing through
the largest artery
called the aorta.