4. Plants
Water & mineral Food
xylem phloem
Vascular
tissues
involves
stem root leaf
structure
translocation
need
Transported by
Relate to
Relate to
involves
Root
pressure
Transpirational pull
Factors
1. Air movement
2. Temperature
3. Light intensity
4. Relative humidity
Capillary
action
affecting
Transpiration
Results in
Found in
4
5. animals
Circulatory system
blood clotting mechanism
Lymphatic
systemLymph
Lymphatic
vessels
Lymph
nodes
Defense
system
immune
system
Blood
Blood
vessel
heart
Closed
system
Open
system
doublesingle
incomplete complete
types
Divided into
includes
needs
contributes
includes
Made up of comprises
When damaged
Blood cells,
blood plasma
comprises
5
6. Defence system
specificNon specific
1st line 2nd
line
3rd
line
•Skin
•mucous
membrane
Phagocyte
Phagocytosis
lymphocyte antibody
passive active
naturalartificial natural artificial
immunisation
immunity
Divided into
Divided into is
through
produce
gives
Divided into
Divided into Divided into
are
Carry out
eg
6
7. The circulatory system
•Delivers nutrients and oxygen to cells
•Carries waste products away from the cells
•Protects the body from infections
•It has three major components;
– A medium
– A pump
– Vessels
7
8. • A medium is required to carry materials
around the circulatory system
• In human and animals blood
• In invertebrates (insects) haemolymph
• The blood is a type of connective tissue
made up of plasma, blood cells and platelets.
8
9. • The heart functions as a muscular pump
that circulates the blood throughout the
body.
• The blood vessels are vessels consisting
of arteries, capillaries and veins that are
connected to the heart to deliver blood to
all body tissues.
9
10. The functions of blood
• Transports oxygen from the lungs to the
cells of the whole body, carbon dioxide
from cells to the lungs.
• Transport nutrients, hormones and
antibodies throughout the body.
• Transport waste products away from the
cells to the organs of the excretory
system.
10
11. • Regulates
– The pH of body fluids
– The body temperature
– The water content of cells
• Protects us
– From excessive blood loss in an injury
through the mechanism of blood clotting
helps to heal wounds.
– From diseases and helps to fight against
infections
The functions of blood…cont
11
12. The function of haemolymph
• Transports water, inorganic salts and
organic compounds throughout the
haemocoel.
• Does not transport respiratory gases
• In insect, respiratory gases are
transported via the tracheal system.
12
16. The differences between arteries, capillaries
and veins
Characteristic Arteries Capillaries Veins
Wall
Thick,
muscular,
elastic
One-cell thick,
no muscle or
elastic tissue
Thin, less
muscular, less
elastic
Lumen Small Very small Large
Valve No valve No valve Have valves
Blood pressure High Very low Low 16
17. Characteristic Arteries Capillaries Veins
Direction of
blood flow
From the heart to
the organs
From arteries to
veins
From all parts of
the body to the
heart
Blood content
Oxygenated blood
except the
pulmonary artery
Oxygenated blood at
the arteriole ends &
deoxygenated blood
at the venule ends
Deoxygenated
blood except the
pulmonary artery
Function
To transport blood
quickly at high
pressure from the
heart to the
Allow rapid gaseous
exchange between
the blood and the
body cell by
Allow blood from
the tissues to
return to the
heart
17
20. The flow of blood in the heart
1. Oxygenated blood from the lungs
enters the left atrium through the
pulmonary veins.
2. Deoxygenated blood from the rest of
the body enters the right atrium via
the vena cava.
3. As blood fills the atria contract and
push the blood through the bicuspid
and tricuspid valves into the two
ventricles. 20
21. The flow of blood in the heart… cont
4. When the ventricles contract, the
semi-lunar valves are forced open
and blood is pushed into the
pulmonary arteries and the aorta.
5. Deoxygenated blood is pumped
through the pulmonary arteries to
the lungs.
6. Oxygenated blood is pump through
the aorta to the rest of the body.
21
22. The pumping of the heart
• Each time the heart contracts, it
acts as a pump which sends blood
throughout the body.
• The heart is made up of a strong
muscle, called the cardiac muscle.
22
23. The pumping of the heart… cont
• The cardiac muscle cells are
interconnected
• This interconnection allows
electrical impulses to spread rapidly
through the heart and, at the same
time, stimulates the cardiac muscle
cells to contract in a coordinated
movement.
23
24. The pumping of the heart… cont
• The cardiac muscle is myogenic.
• This means it contracts and relaxes
without the need to receive
stimulation by nerve impulses to
make it contract.
• The contractions of the heart are
initiated and coordinated by a
pacemaker.
24
25. The pumping of the heart… cont
• The pacemaker is a cluster of
specialised heart ,muscle cells that
set the rate of contraction.
• It is located in the wall of the right
atrium.
• The pacemaker generates electrical
impulses which spread rapidly over
the walls of both atria, causing the
atria to contract rhythmically.
25
26. The pumping of the heart… cont
• The heart’s primary pacemaker is the
sinoatrial (SA) node because it keeps the
heartbeats regular.
• From the SA node, the impulses are
relayed to the atrioventricular (AV) node,
located at the bottom of the right atrium.
• From the AV node, bundle of His fibres,
bundle branches and Purkinje fibres send
the impulses to the apex of the heart and
throughout the walls of the ventricles.
26
29. 1. The SA node generates electrical
impulses.
2. The electrical impulses spread rapidly
over the walls of both atria, making the
walls contract simultaneously.
Contractions of the atria help to pump
blood into the ventricles.
3. The electrical signals reach the AV node.
The bundle of His fibres, bundle branches
and Purkinje fibres send the impulses to
the apex of the heart.
4. The electrical impulses spread to the
ventricles, causing them to pump and
push blood out to the lungs and body
29
31. The regulatory mechanism of blood pressure
• Blood pressure is the force that pumps blood
along the arteries and the capillaries.
• When blood flows along a vessel, it exerts
pressure against the walls of the blood vessel.
• Blood pressure is greater in arteries than in
veins.
• Blood flows from areas of high pressure to
areas of lower pressure.
• During the contraction of the ventricles, blood
pressure is the highest in the aorta and large
arteries when blood is pumped into the aorta
and pulmonary arteries.
31
32. The regulatory mechanism of blood pressure… cont.
• At rest, a healthy adult has a blood pressure of
120/80 mm Hg
• The first number is the systolic pressure, the
highest recorded pressure in an artery when
the ventricles contract (systole stage).
• The second number, the diastolic pressure, is
the lowest recorded pressure during the
relaxation phase of the heartbeats (diastole
stage)
32
38. ProduceTrombokinas
e
Wound in skin
Platelet gather StickyForms a
temporary plug
in leaking vessel
Fibrinogen
Fibrin
Forms the threads
of the clot
Later
Harden (scab)
Mechanism
of blood clotting
Need
Vitamin K
Trombokinase
Ion Calcium
ProthrombinThrombin
38
43. Thread of clot
•Thrombin converts soluble fibrinogen (plasma
protein formed by the liver) into insoluble fibrin.
•Fibrin forms the threads of the clot.
•A mesh-like network of fibrin traps red blood cells
together, forming the blood clot, which later hardens
into a scab. 43
44. Consequences of an impaired Blood
Clotting Mechanism
• Haemophilia is a hereditary disease due to the lack
of certain gene for the production of certain
clotting factors.
• This is an impaired clotting mechanism which
causes serious bleeding particularly in the joints.
• The afflicted person may die as a result of
excessive bleeding from even minor cuts and
bruises because blood clotting cannot take place.
Haemophilia
44
45. Consequences of an impaired Blood Clotting
Mechanism
• Sometimes a local blood clot (thrombus) is
formed on the damaged rough inner wall of
the artery. This may cause blockage of the
artery, a condition known as thrombosis.
• When a thrombus dislodges and is carried
away by blood circulation, it is known as an
embolus. The embolus may be trapped in a
small artery where it blocks the blood flow.
This condition is called embolism.
Thrombosis
45
46. Consequences of an impaired Blood Clotting
Mechanism
• The blocked coronary artery cuts off the
supply of oxygen and nutrients to the heart
muscles, hence causes heart attack.
Thrombosis
46
49. Formation of the Interstitial Fluid and Lymph
• When the blood flows from arteries into capillaries,
there is higher hydrostatic pressure at the arterial
end of the capillaries.
• This high pressure forces some fluid out through the
capillary walls into the intercellular spaces between
the cells.
• Once the fluid leaves the capillary walls, it is called
interstitial or tissue fluid. The interstitial fluids fills
the spaces between the cells and constantly bathes
the cells.
49
50. Formation of the Interstitial Fluid and Lymph
• The interstitial fluid that has not been reabsorbed
into the bloodstream goes into the lymph
capillaries. Once inside the lymph capillaries, the
fluid is known as lymph.
50
51. Composition of the Interstitial Fluid
•The composition of the interstitial fluid is
similar to the blood plasma.
– Consists of water, dissolved nutrients, hormones,
waste products, gases, small proteins and
leucocytes.
– Has no erythrocytes, platelets and large protein
molecules (albumin, globulin and fibrinogen)
51
52. Importance of the Interstitial Fluid
•Interstitial fluid is important because :
– It forms the internal environment of the body.
– It bathes the cells and supplies them with oxygen
and nutrients which diffuse from the blood
through the interstitial fluid into the cells.
– Excretory waste products (carbon dioxide and
urea) diffuse out of the cells into the interstitial
fluid.
52
53. Structure of the Lymphatic System
•The lymphatic system is a one-way system
consisting of a network of lymph capillaries,
lymphatic vessels and lymph nodes.
•The lymph capillaries are blind-ended tubes
located in the spaces between the cells.
•The interstitial fluid that has not been
reabsorbed into the bloodstream goes into
the lymph capillaries. Once inside the lymph
capillaries, the fluid is known as lymph. 53
54. Structure of the Lymphatic System
•Lymph is the colourless fluid found in the
lymphatic vessels.
•Lymph capillaries converge into larger
lymphatic vessels.
•Lymph nodes are located at intervals along
the lymphatic vessels. The lymph nodes
produce lymphocytes that help to protect the
body against infections.
54
55. Structure of the Lymphatic System
•Lymph contains a higher number of
lymphocytes than blood.
•Within the lymphatic vessels are one-way
valves to ensure the continuous flow of the
lymph to prevent the backflow of the lymph.
55
56. The Relationship between the Lymphatic
System and Circulatory System
•Lymph is returned to the circulatory system via
the thoracic duct and the right lymphatic duct.
•The vessels from the left side of the body flow
into the thoracic duct. The thoracic duct is the
largest lymphatic vessel in the body that
carries lymph to the left subclavian vein back
into the bloodstream.
•The right lymphatic duct transport lymph from
the right side of the head and chest into the
right subclavian vein. 56
57. Role of the Lymphatic System in Transport
• Collects the interstitial fluid and returns it to the
circulatory system.
• Fats and fat-soluble vitamins are absorb through
lacteals and transported to the blood circulatory
system.
• The lymph nodes filter out bacteria and other
foreign particles. Phagocytes present in the nodes
engulf and destroy foreign particles.
• Lymphocytes produce antibodies which aid in the
destruction of pathogens and the neutralization of
toxins.
57
59. ROLE OF CIRCULATORY SYSTEM IN THE BODY’S
DEFENCE SYSTEM
• Beside transport function, our circulatory system also defends
the body against disease abolition of the disease-causing
microorganisms or pathogens.
• There are three lines of defence mechanisms in our body:
– The first line of defence: prevention of pathogens entering the
body.
– The second line of defence: killing the pathogens that entered
our body by action or phagocytic white blood cells.
– The third line of defence: killing the pathogens by means of
antibody actions.
Body’s Defence Mechanisms
59
60. • Prevention of pathogens entering the body by mean of
physical and chemical barriers.
• A non-specific defence, that is never differentiate among
various type of pathogens.
i. Skin
– As a physical barrier, skin is made up of a dead keratinised
layer, tough enough for pathogens to penetrate.
– If there is a scratch or cut, the blood clots to seal the wound
and avoids infections.
– Also acts as chemical barrier as it secretes sweat which
contains salt. Sebaceous glands produce sebum which
contains acid and oil. All these substances are unfavourable
for growth of microorganisms.
– Sweat also contain lysozyme which destroy pathogens.
The First Line of Defence
60
61. ii. Tears and Saliva
– Contain lysozymes which protect the eyes and mouth
from pathogen invasion.
ii. Gastric juice in stomach
– Contain hydrochloric acid which destroys most
pathogens in foods and drinks taken.
ii. Mucous membranes
– Secrete mucus in nasal cavity and trachea to trap the
dust particles and spores.
– The cilia in the respiratory track sweep the trapped
particles to the pharynx and stimulates sneeze or cough
to expel out the pathogens.
The First Line of Defence
61
62. • The killing action brought by some of the white blood cells
like neutrophil and monocyte. They are called phagocytes
and the process is phagocytosis.
• It is also a non-specific defence.
• Phagocytosis occur when pathogens get through the first line
defence. Phagocytes move to the infected area due to the
stimulation by chemicals released by damaged cells,
example cut skin.
• Sometimes the phagocytes are killed by toxins produced by
the pathogens.
• Dead bacteria, tissue cells and phagocytes may accumulate
to form pus at the site of injury
The Second Line of Defence
62
63. • The steps involved in phagocytosis by a phagocyte
e.g. Neutrophil
pathogen
pseudopodium
vacuole
63
64. • Neutrophil moves toward a bacterium by using its
pesudopodia.
• Pseudopodia elongate and surround the bacterium.
• Neutrophil engulfs the bacterium to form a vacuole.
• Enzymes (lysozyme) are released into the vacuole to
digest the pathogen.
• Useful product of digestion is the absorbed and
assimilated by phagocyte
64
65. • The third line of defence in the body is antibody.
• Antibody is a kind of protein released by lymphocyte in
response to the presence of foreign substance, called antigen
in our body.
• Lymphocytes are white blood cells found in lymph nodes and
in the blood circulatory system. There are two types of
lymphocytes, B-lymphocyte that secretes antibodies and T-
lymphocyte that helps B-lymphocyte in antibody production.
• An antigen is a substance (usually protein) normally found on
the outer surface of pathogen. Different types of pathogen act
as different types of antigen.
The Third Line of Defence
65
66. • The third line of defence is a specific defence because when a
specific antigen invades the body, lymphocyte is stimulated
and produces specific antibody to destroy these specific
antigens.
• This response is known as immune response because it
resists the body from pathogens or diseases.
• After any infection, some lymphocytes remain in the body as
memory cells which may last for several months or years. This
memory cells help to defend the body against next infection
by the same antigen. During this period, someone is sad to
be immuned for that particular disease.
• Therefore, the word ‘immunity’ refers to the ability of an
organisms to defend itself against infection by pathogens.
The Third Line of Defence
66
67. • What is the mechanism used by antibodies to destroy
antigen?
– Antibody binds to the specific antigen binding site
– Hence, inactivates antigen by several ways
The Third Line of Defence
Neutralisation
Antibody or antitoxin coats the
bacterial toxin or viral binding
sites
67
68. The Third Line of Defence
Agglutination
Agglutinates bacteria cell and
stops their moving and
stimulate phagocytosis
Disintegration (lysis)
Breakdown the bacterial cell
wall.
68
69. The Third Line of Defence
Opsonisation
Attaches itself to the bacteria
surface and stimulates
phagocytosis.
69
70. AIDS
• Acquired Immunodeficiency Syndrome
• Caused by HIV – Human Immunodeficiency Virus
• Attacks the central nervous system and helper T-cells
in the body’s immune system.
• Helper T-cells are essential to activate B-cell
lymphocyte in antibody production.
• HIV needs 8-10 years of incubation period before the
symptom appears.
70
71. AIDS
• The immune system of infected person gradually
becomes weakened and defenceless against many
pathogens.
• Decreases in function of central nervous system
followed by body weight loss.
• Eventually death occurs. The patient does not die
from AIDS itself but from other secondary infections
such as pneumonia and meningitis, tuberculosis,
fungal infections or certain forms of cancer like
Kaposi’s sarcoma
71
72. AIDS – Transmission Methods
• HIV only survive in body fluid such as semen, blood
and vaginal fluid.
• Therefore, HIV can be transmitted through :
– sexual intercourse
– Blood transfusion
– Injection with contaminated needle used to inject drugs
• HIV infected mother can pass HIV to her baby
through placenta or breast milk.
• HIV cannot be spread by touching, sharing of food
or through the use of public toilets. 72
73. Appreciating a Healthy Cardiovascular System
• Disorder of the heart and blood circulatory system;
hypertension, artherosclerosis, coronary
thrombosis, arteriosclerosis, angina, stroke.
• Factors that contribute to cardiovascular diseases;
– Obesity
– A diet high in saturated fat and cholesterol in daily life
and low in fibres.
– Salty foods
– Lack of exercise
– Cigarette smoking
– Mental stress
73
