Transcript Transport in Human

Transport in Human
(人類的運輸系統)

Every cell requires food, oxygen &
other useful materials for
metabolism (代謝作用) .
Food
Oxygen
Useful
materials
Metabolism

Metabolism produces toxic waste
products which must be removed.
Metabolism
Toxic waste products
e.g. carbon dioxide
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Many cells are far away from the
small intestine and the lung.
A transport system
is developed to increase
the
O2efficiency of
exchange
CO2 and transport
of materials.
Food
Transport System
Blood 血液
Blood vessels 血管
Heart 心臟
Blood Cells
Blood
Platelet
White Blood
Cell
Red Blood Cell
Blood

Plasma (血漿) (55%)
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90% water
Dissolved substances:
Dissolved food substances
 Plasma Proteins
 Wastes
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Blood cells (血細胞) (45%)
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Red blood cells
White blood cells
Blood platelets
Red Blood Cells

carry oxygen from lungs to all
parts of body
White Blood Cells
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
kill germs (病菌)
help to defend (防衛) us against diseases
Blood Platelets
involved in blood clotting
(凝血作用)
 are
Blood cells are produced by
bone marrow (骨髓).
Blood Vessels
Vein
(靜脈)
Heart
Capillaries (微血管)
Artery
(動脈)
Arteries
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carry blood from
heart to other
parts of the body
thick wall with
muscles
branch into
capillaries
Capillaries
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the smallest blood vessels
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reach every part of the body
Capillaries
have very thin walls => substances can
diffuse across their walls
 are the places for exchange of materials
between the blood and the cells

CO2, wastes
glucose
O2
Tissue cell
Veins

Capillaries join up to
form veins.
 carry blood back to heart
 thinner walls with less
muscles
 have valves (瓣膜) to
prevent backflow of
blood (血液倒流)
How do valves prevent
backflow of blood?
Valves closed
Valves open
Muscle
contracts
Blood is propelled forward
Valves open Valves closed
Muscle
relaxes
Backflow of blood is
prevented by valve.
Which one is artery?
Which one is vein? Why?
Because the wall of artery is thicker than that of vein.
Heart
Structure of a Heart
Aorta (大動脈)
Pulmonary
artery
(肺動脈)
Right auricle
Left auricle
Right ventricle
Left ventricle
(右心耳)
(右心室)
Coronary blood vessels
(冠狀血管 )
(左心耳)
(左心室)
- supply blood
to the heart
Auricles
Right
Veins
From
other
parts of
body
- receive blood from body
Left
Pulmonary
veins
From
lungs
Heart structure
Ventricles
Right
- pump blood out of the heart
Left
Pulmonary
Artery
Aorta
To
lungs
To other
parts of
body
Heart structure
Structure of a human heart
Pulmonary
artery
Vein
Right
auricle
Vein
Right
ventricle
Aorta
Pulmonary
veins
Left
auricle
Valves
Left
ventricle
Blood Circulation (血液循環)
Blood flow is maintained
by pumping action of the
Heart.
Pulmonary Circulation (肺循環)
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Deoxygenated
blood
returns
from
Right
auricle
ventricle
contracts
pumps
blood
and pump
to
blood
to
O2 (缺氧血)
CO
2lungs
Gaseous
Oxygenated
exchange
blood
Oxygenated
body
the right
through
to the
pulmonary
ventricle
right
auricle
. artery
. .
(氣體交換)
in lungs;
flow
back to
left
Blood
blood becomes
auricle
and then
(含氧血)
oxygenated
to
left ventricle
blood
(含氧血)
through
pulmonary vein.
Deoxygenated
Blood (缺氧血)
body
Systemic Circulation (體循環)
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The blood
Left
After
ventricle
flowing
flows
through
pumps
backoxygenated
to
body,
the heart.
the blood
blood to
all parts of
becomes
deoxygenated
body (except. lungs) via aorta.
Oxygenated
Blood
(含氧血)
body
Deoxygenated
Blood (缺氧血)
Double Circulation (雙循環)
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Blood flows through the heart
twice in one complete circulation
Consists of 2 circuits:
1.
2.
Connection between heart with
lungs .
Connection between heart with
the rest of the body .
Is it possible that
blood flows
backwards in heart?
Why?
Backflow of blood in heart
is prevented by valves .
Valves (瓣膜)
Useful Websites

http://www.ehc.com/vbody.asp

http://www.mercksharpdohme.com/
disease/heart/coronary_health/anato
my/home.html
Eating for healthy transport
system
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Takes in too much fat in diet will
make us put on weight easily
Fatty foods also contain a lot of
cholesterol
Cholesterol is a fatty substance
found in the blood. It is used to
make cell membranes and some
hormones.
Eating for healthy transport
system
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Do you remember the chart used
in teaching Diet and Health?
we can also obtain nutritive
values of common food from the
website of Centre for Food
Safety (食物安全中心)：
http://www.fehd.gov.hk/niis/prese
arch3.html
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Too much cholesterol can
deposit on the inner walls of
blood vessels and harden the
walls.
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The vessels cannot expand
easily when blood is forced
into them. This will result in
high blood pressure.
Eating for healthy transport
system
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Cholesterol deposits may block
the coronary arteries that supply
oxygen & nutrients to the heart
muscle and coronary heart
disease results.
The heart may stop beating due
to the lack of oxygen and this
may cause death.
Eating for healthy transport
system
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If there is a blockage or rupture
in the brain arteries, stroke may
result. This may result in
paralysis.
To avoid the trap of cholesterol
in the body, it is recommended
that we limit our average daily
cholesterol intake to less than
300 mg.