We Present a Science Topic from the book

‘SCIENCE VISION’ Grade 4 (by VWP)

Heart and

Blood Vascular System

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Blood Vascular System

HeartHeart

CapillaryCapillaryNetworkNetwork

ArteriesArteries Veins

Veins

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Aorta

LeftAuricle(atrium)

Vena cava

(veins)

Right Auricle(atrium)

Ventricles

arteries

Our heart

Ventral View

Aorta

vein

artery

artery

vein

heart

Our heart…….It goes on and on and on….

From the moment we start our lives,

till the deathit does not stop for a moment.

What an Organ!

Cells and tissues

Carbon dioxide gets into the blood

Left ventricle

Left atrium

Rightventricle

Lungs

Cells and tissues

Body cells give off carbon dioxide

Impure blood from the body is brought to

heart by veins.

Rightatrium

Remember: Atria are receiving chambers; they receive blood. Ventricles are pumping chambers. They send the blood to

various parts of the body. Left side of the heart has pure blood, (oxygenated blood) Right side of the heart has impure or deoxygenated blood.

Pure blood is supplied to all cells of the body

Lungs

Heart

Body parts

Capillary network

Body parts

Capillary network

Vein from body parts carrying impure blood

Artery from heart carrying impure blood to lungs for purification

Vein bringingPure blood from lungs to heart

Arteries supplying pure blood to body parts

Path of blood in heart, body parts and lungsPath of blood in heart, body parts and lungs

1

2

Blood flows in aBlood flows in a closed network closed network of of

vesselsvessels

Heart is theHeart is the pumping organ pumping organ

Arteries Arteries are the vessels thatare the vessels that

take the bloodtake the blood away from heart away from heart

Veins Veins bring bloodbring blood back to the heart back to the heart

Capillaries Capillaries are very thin walledare very thin walled

vessels;vessels; they join artery to vein they join artery to vein

LeftRightVeins bring blood to

the heart

Veins bring blood to the heart

Right atrium of the heart receives impure blood

Left atrium of the heart receives pure blood

Atria (auricles) are receiving chambers, while ventricles are distributing chambers of the heart.

vein

venules

artery

arterioles

Left ventricle

Right auricle

Right ventricle

Left auricle

What is heart? It is a muscular organ lying in the chest, a little towards the left side.

What does it do? It pumps blood to all parts of the body.

Why is it important to pump the blood to all parts of the body? Because blood carries food material and oxygen to every tiny cell of the body.

Why do cells need oxygen, nutrients (food material) and water?

Because cells are components of the body machine. Each cell itself is a factory where energy is generated as a result of very complicated chemical processes. Cells make use of food material, make energy, and produce waste material. if the cell does not get oxygen it will

suffocate and die.

Look at this diagram of heart. Can you tell:• Which side is right side and which one is the left side?

• Why one side of the heart is shown in dark color?

• What do blue arrows show

• What do white arrows show?

• Can you label this diagram correctly?

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