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The Heart

Left Ventricle

Left AtriumRight Atrium

Right Ventricle

Tricuspid valve

Pulmonary vein

AortaPulmonary artery

Vena cava

Bicuspid valve

AB

C

D

E F

G

H

I J

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Function of heart?

to pump blood to all parts of body

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How does the Heart work?

blood from the

body

blood from

the lungs

- The heart beat begins when the

atria muscles relax and blood

flows into the atria.

-Deoxygenated blood (from whole body)

enter the right atrium via vena cava- oxygenated blood (from the lung) enterthe left atria via pulmonary vein.

STEP ONE

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- The atria then contract and

the valves open to allow

blood into the ventricles.

- Blood in RA go throughtricuspid valve to enter RV

- Blood in LA go through

bicuspid valve to enter LV.

How does the Heart work?

STEP TWO

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How does the Heart work?

- When the ventricles contract, the

tricuspid and bicuspid valve will

close and semilunar valves is forced

to open.

- At the same time, blood is pushedinto pulmonary artery and aorta.

- At the same time, the atria are

relaxing and once again filling with

blood.

- What happen when the ventricles

relax?

The cycle then repeats itself.

STEP THREE

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There are 3 types of blood vessels

a. ARTERY

b. VEIN

c. CAPILLARY

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lumen

Elastic fibre

Wall

(thick, muscular and

elastic)

Wall

(thin, less muscular and less

elastic)

Arteries Veins

Wall

(one cell thick)

Capillaries

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The ARTERYArteries carry blood away from the heart.

Arteri membawa darah dari jantung

the elastic fibres allow the artery to

stretch under pressure

Blood pressure is high

Carries blood from heart to tissues

(organ)

Bring oxygenated blood except

pulmonary artery

Elastic fibre

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The VEIN

Veins carry blood towards the heart.

Membawa darah kepada jantung

veins have valves which act to stop

the blood from going in the wrong

direction.

Blood pressure is very low

Carries blood from tissues (organ)to

the heart

Bring deoxygenated blood except

pulmonary vein

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The CAPILLARYCapillaries link Arteries with Veins

Menghubungkan arteri dan vena

the wall of a capillary

is only one cell thick

Enable the diffusion of gases, nutrients,

hormones, waste product between

blood and tissue

The exchange of materials between theblood and the body can only occur

through capillaries.

lumen

endothelium(one cell thick)

cell

Blood content is mixed

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artery vein

capillaries

body cell

The CAPILLARYA collection of capillaries is known as a capillary bed.

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lungs

head & arms

liver

digestive system

kidneys

legs

pulmonary artery

aorta

pulmonary vein

main vein

LeftRight

PATH OF BLOOD FLOW IN THE BLOOD CIRCULATORY SYSTEM

Circulatory System

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Lungs

Body cells

the right side of the

system

deals with

deoxygenated blood.

the left side of the

system

deals with

oxygenated blood.