1. CHAPTER 2
BLOOD CIRCULATION AND
TRANSPORT

2. 2.1 The Transport System in Human
Being
 Internal transport system is needed to deliver useful
materials to body cells and remove waste materials
 Internal transport system  Circulatory system
 Human circulatory system Double circulatory
system
 Blood must flow through heart twice
 Pulmonary circulation
 Transport blood between heart and lungs
 Systematic circulation
 Transport blood between the heart and all other parts of
body

4. Characteristics of circulatory
system
• Circulating fluid
 Blood
 Transports useful and waste materials
 Pumping device
 Heart
 Move through body by muscular contractions of heart
 Blood vessels
 3 main types of blood vessels: arteries, veins and
capillaries
 Valves
 Present in some blood vessels
 Prevent backflow
 Ensure blood flows in 1 direction only

5. Structure of human heart
To head
From head and body
and body
To lungs
From lungs
Bicuspid valve /
mitral valve
Septum
From trunk
and legs

6. Blood Vessels and Their
Functions
3 types of blood vessels:
 Arteries
 Veins
 Capillaries
 Human circulatory system is called a
closed system

9. Comparisons
Characteristics Artery Vein Capillary
Cross section
Size of lumen Small Big Small
Thickness of Thick, muscular thinner, Wall only one
wall and elastic muscular and cell thick
walls less elastic
Valves Absent Present Absent
Blood flow Fast and under Slow and under Slow and under
very high low pressure high pressure
pressure

10. Characteristics Artery Vein Capillary
Colour of blood Bright red, Dark red, Bright red,
inside contains contains contains
oxygenated deoxygenated oxygenated
blood (except blood blood
pulmonary
artery)
Function Carries blood Carries blood • Connects
away from to heart arteries and
heart veins
• Allows
exchange of
substances
between
blood and
body cells

11. Path of Blood Flow
Aorta
Pulmonary
artery
Pulmonary
vein
Vena cava

13. Maintaining a healthy heart
 Factors
that increase risk of getting heart
disease:
 Heredity
 Cholesterol and obesity
 Lack of exercise
 Smoking
 Stress
 Alcohol

14. Human Blood
Blood
Plasma Blood Cells Blood Fragments
Red Blood White Blood Platelets
Cells Cells
 Plasma makes up 55% of blood by volume
 The other 45% consists of red blood cells, white
blood cells and platelets

15. Plasma
 Yellow liquid in blood
 90% of plasma is water
 10% of plasma include:
 Nutrients: glucose, amino acids and
vitamins
 Proteins:
antibodies, hormones, enzymes, albumins
and fibrinogen
 Inorganic ions: sodium, calcium, chlorides
and phosphates

16.  Main functions of plasma:
 To transport nutrients to tissues
 To remove waste products from tissues
 To distribute hormones, enzymes, antibodies
and other proteins
 To distribute heat energy from liver and
muscles to all other parts of body

17. Red Blood Cells (erythrocytes)
 Biconcave, disc shaped cells without
nucleus

18.  Transport oxygen from the lungs to all parts
of body
 Contain a red pigment called haemoglobin
which combines with oxygen molecules to
form oxyhaemoglobin
 Carry carbon dioxide from body cells to
lungs
 RBC are produced in bone marrow
 Lifespan: 120 days
 When RBC are worn out, they are destroyed
in liver and spleen

19. White Blood Cells (leucocytes)
 WBC are much larger than RBC and they
each have a nucleus
 Usually irregular in shape, colourless and
do not contain haemoglobin

20.  Produced from bone marrow cells
 Lifespan of WBC depends on type of
WBC. It varies from a few hours to a few
months
 Play a vital role in body’s defense against
diseases
 Produce antibodies
 WBC can squeeze through walls of blood
capillaries into the space among the cells
to destroy the bacteria

21. Platelets (thrombocytes)
 Play an important role in blood clotting

22. Blood groups
 ABO system classifies the human blood
into 4 groups called A, B, AB and O.
 During blood transfusion, donor’s blood
must be compatible with the recipient’s
blood
 When an incompatible type of blood is
transfused, RBC of donated blood will
agglutinate and cause fatal blockages in
recipient’s blood vessels

23. Donor’s blood
O A B AB
O
Recipient’s
blood
A
B
AB
Compatible
Incompatible

24.  Blood group O can safely donate blood,
in small quantities, to anyone. People with
group O are called universal donors
 Blood group AB can safely receive blood
from anyone. Group AB people are
called universal recipients

25. Transport system in Plants
Wilting
 Non woody plants depend on the water
stored in the cells of the stem for support
 Wilting occurs in non woody plants when
water loss through aerial parts of plant
exceeds water absorption by roots
 Cells in plants lose their turgidity (stiffness)
and the plant droops

26. Transport Tissues in Plants
 Transport system in plants is made up of
 Xylem tissues
 Phloem tissues
 They are found in roots, stems and leaves

27. Cross section of root
Cross section of stem

28. Cross section of leaf
Upper
epidermis
Lower
epidermis

29. Xylem tissues
 Made up of xylem vessels
 Form woody tissues of plants and give
support
 Transport water and dissolved minerals from
roots, up the stems and to the leaves

30. Phloem tissues
 Transportfood substances from leaves to
the stems and roots
 Xylem and phloem tissues form vascular
bundles