Transcript Circulatory System

The 3 main parts of The
Circulatory system
 The
Heart
 The
Blood Vessels
 Blood
The Heart
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Is a pump
Actually it is TWO pumps
One pump deals with blood to the lungs, the
other pump deals with blood to the body.
Heart is made of Cardiac Muscle
The two sides are separated by a thick wall
of muscle called the SEPTUM
The blood for the two pumps is kept
separate in mammals.
Septum
Fetal Heart circulation
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Because the fetus is not using its lungs,
the blood is “shunted” between the right
and left atria through a hole called the
foramen ovale. This usually closes within
the first days of birth.
Babies who do not have the foramen
ovale closed are born with a “hole in the
heart”
Structure of the Heart.
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Four chambers, 2 upper called ATRIA
& 2 lower called VENTRICLES
The Right side of the heart receives deoxygenated
blood from the body via the superior and inferior
vena cava.
The Left side receives oxygenated blood from the
lungs via the Pulmonary veins
Valves of the Heart
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Between the right atria and right ventricle is the TRICUSPID valve
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Between the left atria and left ventricle is the MITRAL valve.
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SEMILUNAR valves are found at the base of the PULMONARY artery and
AORTA.
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The purpose of the valves is to prevent blood flowing backwards.
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Leaking of these valves can result in a heart murmur
Watch the heart valves at this link
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http://watchlearnlive.heart.org/CVML_Player.php?moduleSelect=an
atom
Path of Blood in heart
https://www.youtube.com/watch?v=BEWjOC
VEN7M
(Pulmonary valve)
(Aortic valve)
(tricuspid valve)
(Mitral valve)
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/table22-3_blood_flow_th.jpg
Cardiac Cycle - Heart
Beat.
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Phase 1 SYSTOLE – Contraction
Occurs when the Ventricles contract, closing the AV Valves
and opening the SL Valves to pump blood into two major
vessels leaving the heart.
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Phase 2 DIASTOLE – Relaxation
Occurs when the Ventricles relax, allowing the back
pressure of the blood to close SL Valves and opening AV
valves.
https://www.youtube.com/watch?v=jLTdgrhpDCg
Your blood pressure is recorded as two numbers. The
systolic blood pressure (the “upper” number) tells how
much pressure blood is exerting against your artery walls
while the heart is pumping blood.
The diastolic blood pressure (the “lower” number) tells
how much pressure blood is exerting against your artery
walls while the heart is resting between beats.
Atrial Systole
Ventricular Systole
Ventricular Diastole
Blood pressure activity
Cardiac Output & Fitness
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Like all muscles, the heart needs exercise
The volume of blood pumped out by the
heart is known as the CARDIAC OUTPUT.
Factors that affect cardiac output are heart
rate and stroke volume
Cardiac output = heart rate X stroke volume
Stroke volume (SV) is the amount of blood pumped out of the heart
(left ventricle - to the body) during each contraction measured in
mL/beat (milliliters per beat).
Average person data
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Stroke volume = 70mL
Heart rate = 70 beats/minute
Cardiac cycle = 70mL X 70beats/min
= 4900mL/min
There is a correlation between heart
health and fitness
Relationship between stroke
volume, heart rate & and cardiac
output
Individual
A
Cardiac
output
Stroke
Volume
mL/beat
Heart Rate
Beats/min
•C is exceptionally fit has
a high stroke volume
and maintain a low hear
rate.
4900
70
70
•B is less fit
•Regular cardiovascular
exercise increases the
resting stroke volume.
B
4900
50
98
C
4900
140
35
D
9800
70
140
•Fitness is measured by
how quickly the heart
rate returns to the
resting rate before
exercise began.
Pulse activity
Types of Blood Vessels
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Arteries
-Carry blood away from the Heart
-The Aorta is the largest artery
Veins
-Carry blood to the Heart
-Veins contain valves
-The Vena Cava is the largest vein
Capillaries
-Known as the “Distribution Pipes”
Arteries
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Thick, muscular, hollow tubes which are highly
ELASTIC
– allows them to DILATE (widen) and
CONSTRICT (narrow) as blood is forced down
them by the heart
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Arteries branch and re-branch, becoming smaller
until they become small ARTERIOLES which
are even more elastic.
– Arterioles force blood into the capillaries (high
pressure).
Veins
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VENULES (very small veins) merge into VEINS which
carry blood back to the heart (low pressure).
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The vein walls are similar to arteries but thinner and less
elastic.
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Veins possess valves at intervals to prevent the backflow
of blood as it moves against the force of gravity back to
the heart.
CAPILLARIES
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Distribute the nutrients and oxygen to the body's tissues
(blood pressure) and remove deoxygenated blood and waste
by diffusion.
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They are extremely thin, the walls are only one cell thick and
connect the arterioles with the venules (blood cells travel
single-file).
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No cell in the body is more than 2 cells away from a
capillary
Function of Blood
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Transport oxygen – oxyhemoglobin
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Transport nutrients: - glucose, amino acids,
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Transport wastes – CO2 , urea, water
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Transport hormones – adrenalin, sex hormones etc.
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Transport heat
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Clotting during injury
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Provide immune response: - white blood cells
Blood is made up of: Plasma
Blood is made up of: Cells
The Composition of Blood
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The Plasma
(Fluid) makes up
55%- 60% of the
blood volume.
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The Solids
(Cells) make up
40%- 45% of the
blood volume.
ERYTHROCYTES (red cells)
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Made in the Bone Marrow and destroyed in
the Spleen.
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Live for about 120 days
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Contain Hemoglobin
(transports oxygen to body
and CO2 to lungs)
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Are Bi-concave discs
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Have no nucleus
Your normal RED BLOOD CELL COUNT or Hb is
between 12 and 14,
(some hospitals measure this as 120 to 140,
both are correct, just different units used).
Liver or Kidney disease causes
RBC to be damaged or destroyed
LEUKOCYTES (white cells)
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Help the body fight bacteria and infection.
THROMBOCYTES (platelets)
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Your normal PLATELET COUNT is between 150 and
400 (Which is actually 150,000 to 400,000 per
cubic millimetre of blood!!!)
Platelets… are made in the bone
marrow
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Concerned with blood clotting.
Circulate in the blood for about 10 days then die.
How much blood is in the
average person?
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Enough to fill one
or two one-gallon milk
jugs.
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Blood accounts for
about seven percent of
human body weight,
and its density is only
slightly more than that
of pure water.
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A man weighing 154 pounds (70
kilograms) would have about 5.5
quarts (5.2 liters) of blood.
A woman weighing 110 pounds (50
kilograms) would have about 3.5
quarts (3.3 liters) of blood.
How much blood can a
human lose?
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An adult human can lose 10-15%
without clinical damage.
If one loses 30% it can be fatal
(haermorraghic [shock due to loss of
blood]).
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An "average" adult male has some 5
litres of blood.
Sudden loss of 1/3 of his blood can be
fatal.
However if the lose rate is slow (say:
24 hours) he can lose as much as 2/3
of the blood with much risk (well
documented).
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So it's not only the amount of blood
that one is losing but, the rate one
loses it. It's also a matter of
maintaining the blood pressure.
Interesting....
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In one day, your blood travels nearly
12,000 miles.
Your heart beats around 35 million
times per year.
Your heart pumps a million barrels of
blood during the average lifetime -enough to fill three supertankers.
Vascular System Problems
Aneurysm
Arteriosclerosis
Atherosclerosis
Varicose veins
Anemia
Aneurysm
A fluid-filled
bulge found in
the weakened
wall of an
artery which
may eventually
rupture and
lead to cell
death (common
cause of
strokes)
Arteriosclerosis
Degeneration of
blood vessel
due to
accumulation
of fat deposits
along the inner
wall.
Atherosclerosis
Blood vessels thicken, harden, wind,
and lose their elasticity
Varicose
Veins
Weakening
of the veins
that causes
blood to
pool and
vessels to
bulge.
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Sickle Cell disease – RBC are not round but sickle
shaped, (genetic mutation for assisting in Malaria
prevention) results in blood cells being destroyed
prematurely.
More commonly associated with people of African
decent.
Anemia
Reduction of blood oxygen due to low
levels of hemoglobin or poor red
blood cell production
Normal
Low Iron