Transcript The circulatory system: the transport of blood around the body

The circulatory system: the
transport of blood around the
body
Aims of the session
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To recap on the previous session: the
structure and function of the heart.
To introduce the body’s method of
transporting blood around the body.
To explain blood pressure and what
effects a persons blood pressure.
Introduce types of blood vessels and
blood cells.
The Heart
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Right side – deoxygenated
Left side – oxygenated
Separated by a thick walled septum
Right atrium and ventricle connected by
tricuspid valve
Left atrium and ventricle connected by
bicuspid (mitral) valve
Cuspid valves held shut by Chordae Tendinae
Left ventricle is thicker than the right
Vessels of the Heart
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Pulmonary artery*
Pulmonary vein
Superior and Inferior Vena cava
Aorta*
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*Semi-lunar valves
Control of the Heart
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Sinoventricular node (SV node)
Sends waves of excitation along Purkinje
Fibres which collectively make up the Bundle
of Hiss. Along septum, radiate upwards
Ventricles contract
Both atria and both ventricles contract at the
same time
Systole-contraction of heart
Diastole-Relaxation/filling of the heart
Blood pressure
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Systolic blood
pressure.
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When the heart
contracts pushing the
blood out through the
arteries.
Blood pressure
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Diastolic blood
pressure, when the
heart is relaxed and
allows blood to
enter.
Factors affecting blood
pressure
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Age
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Gender
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Blood pressure in generally higher in males.
Exercise
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Blood pressure tends to increase with age.
Blood pressure increases in short-term exercise but
decreases in long-term.
Stress
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Stress increases blood pressure through adrenalin and
other hormones.
Effects of high blood pressure
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Angina
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Heart Attacks
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Sharp pains in the chest, mainly caused by the
heart not getting enough oxygen.
The heart stops beating due to lack of oxygen.
Strokes
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Damage to the brain due to oxygen starvation.
Blood vessels
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There are three types of blood vessels
you need to know:
Arteries
Veins
Capillaries
Arteries
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Carry oxygenated
blood away from the
heart (the
pulmonary artery
brings blood to the
heart!!)
They have thick
strong elastic walls.
Small arteries are
called arterioles.
Veins
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Carry deoxygenated
blood back to the heart
(the pulmonary vein
carries blood away from
the heart!!).
The veins have thinner
walls as the blood
pressure is lower.
Veins have valves that
keep blood flowing in
the right direction.
Small veins are called
venules.
Capillaries
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Carry digested foods
and oxygen directly
to the tissue.
Take away waste
products of the
body.
Very small and vary
in size.
How it works!!
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Heart
Arteries
Arterioles
Capillaries
Venules
Veins
Heart
Gas exchange
Blood
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Blood is made up of:
Cells
Platelets
Plasma
Blood cells
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Red Blood cells carry
oxygen around the
body in
haemoglobin.
They have no
nucleus (brain) thus
leaving more space
for oxygen
White blood cells
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Fight against
disease.
Destroys bacteria by
using antibodies.
Fights toxins by
using antitoxins.
Kills foreign
microbes by
consuming them.
Plasma
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Includes everything.
Blood cells.
Digested foods
(glucose).
Waste.
Hormones.
Platelets
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Platelets re tine
fragments in the
body that help blood
clot at wounds.
Warm-up questions
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How many circuits are there in the circulatory
system?
What type of blood is carried back to the
heart?
Which type of blood vessel carries blood
away from the heart?
Which type of blood cell carries oxygen?
Which type of blood cell fights diseases?
Next Seminar