circulatory system form5

7/29/2019 Circulatory System form5

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Circulation

The circulatory systemcarries blood and

dissolved substance to

and from different placesin the body.

Our body resembles a

large roadmap, There

are routes or arteriesthat take you downtown

to the heart of the city.


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3 Major Parts of the Circulatory

system

Medium blood or haemolymph- carries important *stuff through

body

Heartpumps or pushes blood through body

Blood Vessels arteries, veins andcapillaries.

- routes blood travels

* Stuff includes oxygen, food, & waste


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whats in

Erythrocytes

(red blood cells)Leucocytes

(white blood cells)

plateletsplasma


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The Blood

plasma

red blood cell white blood cell

platelets


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Plasma

A straw-coloured

liquid thatcarries thecells and theplateletswhich helpblood clot.

carbon dioxide

glucose

amino acids

proteins

minerals

vitamins

hormones waste materials

like urea.

It also contains usefulthings like;


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Erythrocytes


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Erythrocytes

contain haemoglobin, amolecule specially designedto hold oxygen and carry it

to cells that need it.

can change shape to an amazingextent, without breaking, as itsqueezes single file through the

capillaries.

a biconcave disc that isround and flat withoutanucleus


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Platelets

Platelets are bits of cell

broken off larger cells.

Platelets producetiny fibrinogenfibres to form a net.

This net traps otherblood cells to form ablood clot.


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Leucocytes

Fight and kill

germs thatmay enter your

bloodstream


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Granulocytes Agranulocytes

Leucocytes

Neutrophils Eosinophils Basophils Lymphocytes Monocytes


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Erythrocytes Leucocytes

Has biconcave disc

shape

No fixed shape

No nucleus Has a big nucleus

Transporting Oxygengases Fight infection invarious way


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blood from the heart gets around

the body through blood vessels

There are 3 types of blood vessels

a. ARTERY

b. VEIN

c. CAPILLARY


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lumen

Elastic fibreWall

(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 stretchunder 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 whichact to stop the blood

from going in the wrongdirection.

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 capillaryis only one cell thick

Enable the diffusion ofgases, nutrients,

hormones, waste productbetween blood and tissue

The exchange of materialsbetween the blood and thebody can only occur throughcapillaries.

lumen

endothelium(one cell thick)

cell

Blood content is mixed


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artery vein

capillariesbody 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

How does this system work?

Circulatory System


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Lungs

Body cells

Our circulatory system is a double circulatory system.

This means it has two parts

the right side of

the system

deals with

deoxygenatedblood.

the left side of

the system

deals with

oxygenatedblood.

Circulatory System


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The Heart

These are arteries.They carry bloodaway from the heart.

This is a vein. It bringsblood from the body,except the lungs.

Coronary arteries,the hearts ownblood supply

The heart has four chambers

2 atria

2 ventricles

now lets look inside the heart


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The Heart

Left Ventricle

Left AtriumRight Atrium

Right Ventricle

Tricuspid valve

Pulmonary vein

AortaPulmonary artery

Vena cava

Bicuspid valve


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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 venacava

- oxygenated blood (from the lung)enter the left atria via pulmonaryvein.

STEP ONE


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- The atria then contractand the valves open toallow blood into the

ventricles.- Blood in RA go through

tricuspid valve to enter

RV- Blood in LA go throughbicuspid valve to enterLV.


STEP TWO


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- When the ventricles contract,the tricuspid and bicuspidvalve will close and semilunarvalves is forced to open.

- At the same time, blood ispushed into pulmonary arteryand aorta.

- At the same time, the atriaare relaxing and once again

filling with blood.- What happen when the

ventricles relax?

The cycle then repeats itself.

STEP THREE


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Lub

If you listen toyour heartbeat,it makes a lubdub sound.

The lub is when bloodis pushed out of the

heart into the bodyand the dub is thereloading of the heartwith more blood readyto push it out to the

body

Dub

Th i f h t


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The pumping of heart

Cardiac muscle is myogenic, which means

can contract and relax without the impulsefrom nervous system.

The pumping of heart coordinated by a

pacemaker The primary pacemaker is known as SA node

which located at upper wall of right atrium

The impulse from SA node will cause theatria to contract before the impulse reach the

AV nodes which located at the bottom wall of

right atrium.


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From AV node, the impulses spread tobunle of His, bundle branches and

Purkinje fibres which cause the ventricles

to contract. The pacemaker is regulated by:

Parasimpathetic nerve: slow down the heart

beat Sympathetic nerve: speed up the heart beat.

Adrenaline hormone: speed up the heart beat

during fear/excitement


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1.7 contraction of skeletal muscle

around the veins

Blood pressure in veins is lower compared

to artery.

Therefore, the flows of blood back to heart

are helped by

When the skeletal muscles contract, the

veins will constrict and the blood push

along the veins in one direction due to thepresence of valve in vein.


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SUMMARY

copy and complete the following;

Arteries take blood ______ from the heart. The walls of an artery

are made up of thick _________ walls and elastic fibres. Veins

carry blood ________ the heart and also have valves. The

_________ link arteries and veins, and have a one cell thick wall.

Blood is made up of four main things ______, the liquid part of the

blood; Red Blood Cells to carry ______; White Blood cells to protect

the body from disease and _________ to help blood clot.

away

platelets

towards

capillaries

plasma

oxygen

muscular

circulatory system form5

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