The document discusses the human circulatory system and its key components. It explains that multicellular organisms require a transport system to efficiently distribute nutrients, oxygen, and waste throughout the body. It then describes the major parts of the human circulatory system, including the heart, blood, and blood vessels. The heart pumps blood through the vessels and uses double circulation to oxygenate blood in the lungs and transport nutrients and oxygen to cells. The blood contains plasma, red blood cells, white blood cells, and platelets that each serve important functions in circulation and immunity.

1. transport
in humans

2. learningOBJECTIVES
At the end of the lesson, you should be able to:
- Explain why multi-cellular organisms such as human
beings and plants need a transport system.
- Describe the parts of the human transport system –
heart, vessels, blood.
- Describe the parts of the heart - atrium, ventricle. 4
main vessels from and to the heart.
- Describe the different components of blood and
their functions.
- Explain how blood acts as a transport medium.
- Explain how diffusion and osmosis are involved in the
transport system.
- Describe double circulation.

3. funFACT
It would take about
1,200,000 mosquito bites
to completely drain the
average human of blood.
(Discover magazine,
August 2007)

4. whyTRANSPORT?
If you stay within 500 m – 1 km of the school,
you probably would not mind walking to school…

5. whyTRANSPORT?

6. whyTRANSPORT?
BUT if you stayed at Bedok, Woodlands, or even Boon
Lay…
You would probably take a form of public transport.
(or go to a school within walking distance…)
WHY?

7. whyTRANSPORT?

8. whyTRANSPORT?
Likewise, in unicellular organisms,
The cell is in direct contact with the external
environment.
Diffusion alone is enough to:
- transport essential materials such as oxygen
and nutrients to the cell
- remove waste such as carbon dioxide rapidly

9. whyTRANSPORT?

10. whyTRANSPORT?
In multicellular (complex) organisms,
Cells are far from the external environment.
Diffusion alone is too slow to:
- transport essential materials such as food to
the various organs
- remove waste products efficiently

11. whyTRANSPORT?
Thus, a transport system is developed to move these
substances
 eg. Blood system in humans
This will ensure
- a continual supply of nutrients, oxygen and other
useful materials for metabolism
- the removal of toxic waste products produced by
metabolism

12. circulatorySYSTEM
The human circulatory
system consists of three
parts: heart
• heart (pumps blood
blood
around the body)
vessels
• blood (liquid which
blood
carries materials)
• blood vessels (tubes
which carry blood around
the body)

13. theHEART
left atrium
right atrium
left ventricle
right ventricle

14. theHEART

15. theHEART
• pumps blood around the body
• all mammals have hearts that are
similar in structure
• human heart is about the size of our
fists
• made up of cardiac muscles
• comprises 4 chambers
 2 upper chambers called atria
(left and right)
 2 lower chambers called
ventricles (left and right)

16. theHEART
• right side of heart pumps blood to
lungs only (which are a short
distance from the heart)
• left side of heart pumps blood
around the body (which are further
away from the heart)
• hence left ventricle has thicker
muscular walls than the right
ventricle

17. theHEART
The blood is then
De-oxygenated pumped from the
This blood passes
blood from the body ventricle out of
left Oxygenated blood
from the right
enters the right atrium heart to the restthe lungs enter
from
ventricle the out into
then
and then into the the left atrium and
the lungsthe body
of
right ventricle flow into the left
ventricle
Right atrium Left atrium
Left ventricle
Right ventricle

18. theHEART
This blood passes The blood is then
from the right pumped from the
ventricle then out into left ventricle out of
the lungs the heart to the rest
of the body
De-oxygenated Oxygenated blood
blood from the body from the lungs enter
enters the right atrium the left atrium and
and then into the flow into the left
right ventricle ventricle
Right atrium Left atrium
Left ventricle
Right ventricle

19. bloodCIRCULATION
• In mammals, blood flows through the heart
twice in one complete circuit. This is known as
double circulation.

20. bloodCIRCULATION
From the heart to the lungs and
back to the heart,
• In the lungs, the blood collects
oxygen and releases carbon
dioxide.
• Blood that returns to the heart
is now rich in oxygen, called
oxygenated blood.

21. bloodCIRCULATION
From the heart to the rest of the
body and back to the heart,
• As blood passes the small
intestine, it collects digested
food.
• The blood supplies all the cells
of the body with this digested
food together with oxygen
picked up in the lungs.
• After oxygen is deposited in
body tissues, the blood now has
little oxygen, called
deoxygenated blood.

22. systemicCIRCULATION

23. circulatorySYSTEM
The human circulatory
system consists of three
parts: heart
• heart (pumps blood
blood
around the body)
vessels
• blood (liquid which
blood
carries materials)
• blood vessels (tubes
which carry blood around
the body)

24. bloodCOMPONENTS

25. BLOOD
Has two main functions:
 To carry materials round the body. These
materials include nutrients, oxygen, carbon
dioxide and other waste substances.
 To protect us against diseases.
BLOOD
plasma red blood cells white blood cells platelets

26. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
PLASMA
•Pale yellowish liquid
•Contains mainly water (90%)
•Contains mainly dissolved substances
 like nutrients (digested food), hormones,
antibodies and waste products (carbon
dioxide and urea).

27. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
•Contains haemoglobin
 gives RBC red colour when
combined with oxygen; or
purplish colour when
combined with carbon dioxide
 combines reversibly with
oxygen so RBC can transport
oxygen around the body

28. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
•Does not contain nuclei
 More space to contain
haemoglobin for oxygen
transport

29. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
WHITE BLOOD CELLS

30. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
WHITE BLOOD CELLS
•Much bigger in size than RBC
•Fewer in number than RBC
•Colourless (no haemoglobin)
•Contains a nucleus

31. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
WHITE BLOOD CELLS
•Two types:
 Phagocytes  Ingests foreign
particles by phagocytosis
 Lymphocytes  Produces antibodies
that neutralise bacteria and viruses

32. bloodCOMPONENTS
BLOOD
red blood cells white blood cells Platelets
plasma
(erythrocytes) (leukocytes) (thrombocytes)
PLATELETS
•Cell fragments (not complete cells)
•No nucleus
•Involved in the process of blood clotting

33. circulatorySYSTEM
The human circulatory
system consists of three heart
parts:
blood
• blood vessels
• heart blood
• blood vessels

34. bloodVESSELS
• The blood vessels are a network of tubes to carry
blood around the body.
• Namely the artery, vein & capillary

35. bloodVESSELS - summary
Artery Vein Capillary
Structure Thick, elastic, Thinner, less One-cell thick
muscular walls elastic, less endothelium
muscular walls
Functions Transports Transports Transports
blood away blood towards nutrients &
from the heart the heart waste
materials
Blood High blood Lowest blood Low blood
pressure from pressure pressure
Pressure heart

36. bloodDISORDERS
Condition/ Description Possible causes Treatment
Disease
Haemophilia Genetic illnesses that Lack of one of the No cure, controlled
affect the ability of clotting factors by regular injection of
blood to clot caused by a deficient the deficient clotting
gene factor
Anaemia Deficiency of red Excessive blood loss, Iron supplement,
blood cells or deficient blood cell increased intake of
haemoglobin production (such as food rich in iron,
due to deficient iron blood transfusion
intake)
Leukaemia Cancer of the blood Exposure to Chemotherapy, bone
or bone marrow radiation, certain marrow transplant
characterised by chemicals or viruses,
excessive production genetic
of usually white blood predisposition
cells

37. heartDISEASES
Disease Description Possible causes Treatment
Heart attack Occurs when blood supply to a Blood clot in heart Ensure oxygen intake,
part of the heart is interrupted arteries bypass surgery,
leading to damage or death of Increased risk factor: medications
heart tissue smoking, excessive
alcohol consumption,
abuse of drugs, high
cholesterol,
hypertension,
diabetes, heart
diseases
Stroke Rapid loss of brain function due Blood clot, Medications, ensure
to interruption of blood supply to haemorrhage (share oxygen intake, surgery
all or part of the brain some of the risk
factors as heart attack)

38. bloodTRANSFUSION
• Process of transferring blood or blood-based
products from one person to the circulatory system of
another
• Life-saving especially to people who suffer
excessive blood loss due to trauma or surgery
• Compatibility of blood types:
Individual with blood type Can accept blood of type
A A, O
B B, O
AB A, B, AB, O
(Universal recipient)
O O
(Universal donor)