Download Blood circulation

Circulatory system
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What are we going to learn ?
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Heart
Blood circulation
Blood vessels
Blood
Blood groups
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Heart
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Acts like a pump of the
circulatory system supplying
blood to the whole body
Located between the lungs a little
to the left; size roughly equal to a
fist
Made up of muscle with a dual
protective layer
Two internal sections
unconnected to each other
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Left section contains Oxygen-rich
blood received from the lungs
Right section contains Oxygen-poor
blood to be sent to lungs
Each section has two chambers
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Upper chamber called Atrium;
Lower chamber called as Ventricle
Atrium and ventricle connected to
each other by a one-way valve
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Heart
Internal structure
Superior vena cava
(carries blood to heart)
Right pulmonary veins
(carry blood from lungs)
Pulmonary artery valve
Right atrium
Tricuspid valve
Aorta (carries blood to
body)
Left pulmonary
arteries (carry blood to lung)
Left atrium
Aorta valve
Mitral valve
Left ventricle
Right ventricle
Inferior vena cava
Pericardium
(carries blood to heart)
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How does the heart function?
Oxygen-poor blood
from all over the
body
Oxygen-rich blood
from the lungs
Both atria expand and the
blood enters right atrium
through vena cava and left
atrium through pulmonary
veins
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Atria contract,
both valves open
and blood enters
ventricles
Both valves close so that blood
cannot go back to atria.
Ventricles contract and blood
goes out to lungs through
pulmonary arteries and to the rest
of the body through the aorta.
Atria then expand and the cycle
starts again.
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Heart beats
 Heart beats occur due to the
rhythmic expansion-contraction of
the heart muscles.
 Normally they range between 60
to 80 per minute.
In other words the heart
expands and contracts almost
one hundred thousand times
day !
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Blood circulation
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This is the process of supply of
blood to all the limbs of the
body and its return to the heart.
Two types
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Lungs
Pulmonary circulation: Oxygenpoor blood travels from the heart
to the lungs and Oxygen-rich
blood travels back
Systemic circulation: Oxygen-rich
blood travels from the heart to the
all the limbs of the body and
Oxygen-poor blood travels back
Cells in the body
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Blood circulation video
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Blood vessels
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Blood circulates through
blood vessels
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Network of vessels spread
throughout the body
Circulation only in one
direction
Three types
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Arteries
Veins
Capillaries
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Arteries
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Carry blood from the heart to
various limbs
No valves
Blood flows under pressure
(100mm of Hg)
Other than pulmonary arteries all
arteries carry Oxygen-rich blood
Walls of arteries are made of three
layers of muscle. These thick
walls contract and push blood
forward
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Veins
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Except for pulmonary veins all
other veins carry Oxygen-poor
blood from various limbs to the
heart
Walls are thin
Valves stop blood from flowing
in reverse direction
Blood flows under low pressure
(2 mm of Hg)
Valves permit flow
only in one
direction
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Capillaries
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Consist of a network of microscopic vessels joining
arteries with veins
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Extremely thin walls
Capillaries permit exchange of nutrients, gases etc.
in the blood with the cells
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Capillary
network
Artery
Veins
Cells
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Constituents of blood - 1
Plasma
Red blood cells
Oxygen
White blood cells
Blood
Platelets
Carbon dioxide
Unwanted items
Ammonia, Urea
Nutrients
Hormones
(Glucose, Amino acids)
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Constituents of blood - 2
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Plasma
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Blood cells
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Red blood cells
Platelets
Light yellow colour
Alkaline
90% water, 7% proteins, 3% nonorganic matter
Plasma 54.3%
Red blood cells
White blood cells
Platelets
White blood cells
and platelets 0.7%
White blood cells
Plasma
Red blood cells
45%
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Red blood cells
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Circular shape, No nucleus,
concave on both sides
Function: Supply Oxygen to
body cells
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Hemoglobin in the red blood
cells acts as the transport of
Oxygen
1 cubic mm contains 500 to
600 thousand red blood cells
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White blood cells
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Colourless, amoeba-like
cells with nucleus
Function: Protect body
from bacteria
1 cubic mm contains 5000
to 10000 white blood cells
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Platelets
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Small, irregular shape
Function: Help in coagulation
of blood
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After a wound platelets create a
network of fibrin strings
Red blood cells are trapped in
the network and form a scab on
the wound
1 cubic mm = 150 to 400
thousand platelets
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Blood groups
Blood is grouped into 4 categories based on proteins in it
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A, B, O, AB
Sub-groups Rh+ and Rh- in each group
Before donating blood the blood groups have to be matched as under
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Blood group of Blood can be donated to Blood can be received
a person
from
A
A, AB
A, O
B
B, AB
B, O
AB
AB
A, B, AB, O
O
A, B, AB, O
O
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The end
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