Transcript Circulatory System

Circulatory System
Human Circulatory System
• This is the transport system of the body and
has four main functions;
Human Circulatory System
This is the transport system of the body and has
four main functions;
1. Transportation of H2O, O2 and CO2
2. Distribution of nutrients (from digestion) and
removal of wastes
3. Maintenance of body temperature
(Vasoconstriction/Vasodilation)
4. Circulation of Hormones
What does the system need in order to
meet all of it’s functions?
• Needs to be able to reach every cell in the
body
• To distribute the necessary nutrients in a
usable form
• Has to do all of this without disrupting the
other systems in the body.
What does the system need in order to
meet all of it’s functions?
• Needs to be able to reach every cell in the bodyArteries, Veins and capillaries stretch throughout
the whole body in order to reach every cell.
• To distribute the necessary nutrients in a usable
form- Blood is a fluid in which nutrients are
supported.
• Has to do all of this without disrupting the other
systems in the body- A pump (the heart) pushes
the fluid (the blood) through the body (arteries,
veins and blood vessels) without affecting other
systems
Circulatory VS Cardiovascular
• On your own, you have two minutes to find
the difference between the Circulatory system
and the Cardiovascular system.
• What each system does, what parts of the
body are involved, how they may overlap?
Put these into a Glossary page
• Circulatory-A system that circulates blood
throughout the body, consisting of the heart
and blood vessels as well as the lungs.
• Cardiovascular- System that involves the heart
and blood vessels
What is blood?
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Red Blood cells
White blood cells
Plasma
Platelets
Plasma
• 55% of blood by volume is plasma of that 91%
is water, the remainder largely consists of
dissolved protein
• Plasma suspends red blood cells
• Buffers the Ph of blood
• Promotes clotting
White blood cells
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Less than 1/10th of 1% of blood by volume
Destroy foreign cells
Remove debris
Immune response
Life is variable, shorter if infection is present
Red blood cells
• 45% of blood is red blood cells
Red blood cells
• Transport oxygen via haemoglobin
• Haemoglobin is a protein containing iron
which oxidises in the presence of oxygen
• Therefore oxygenated blood is red
• Have no nuclei
• Last for 120 days
• Produced in the bone marrow
Platelets
• Less than 1/100th of 1% of blood by volume
• Clump together to block holes in blood vessels
• Platelets membranes break releasing clotting
factors
• Converts soluble protein to insoluble fibrin
• Causes blood cells to stick together
• Live about 1 week
Blood disorders
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Leukaemia; high numbers of white blood cells
Anaemia; too few red blood cells
Polycythemia; too many red blood cells
Haemophilia; deficiency in clotting agents
• Carbon Monoxide Poisoning-
Glossary
• Red Blood cells (erythrocytes)- Transport Oxygen
around the body via haemoglobin, have no
nucleus, large % of blood is RBC (45%).
• White blood cells (leukocytes)- Protect the body
against micro-organisms and toxins and contains
a nucleus. Involved in the immune response.
• Plasma-Liquid component of blood,
• Platelets- Blood clotting agent. 1/100th of 1%
(.01%) of blood by volume.
Concept!
• Blood is the fluid of the circulatory system. It
is essential to life.
• It consists of a solid part, the cells, and the
liquid part, plasma.
• Blood carries oxygen and nutrients to and
from the cells via arteries, veins and
capillaries.
The Heart
The Heart
• The heart is a two sided, four chambered
pump.
• It is made up mostly of muscle.
• Unlike all the other muscles in the body, the
heart muscle cannot afford to get tired....Why?
The Heart
1. The heart is the size of a fist.
2. It is made of a very strong muscle.
3. The heart is divided into four chambers: right
atrium, right ventricle, left atrium, left
ventricle.
4. A series of valves open to allow blood flow
from one chamber to the next.
5. A muscle wall called the septum separates the
left and right side of the heart
Functions
1. It contracts sending
oxygen-rich blood to
the tissues and
oxygen-poor blood to
the lungs.
2. The nervous system
controls heart beat
and tissue known as
the pacemaker also
controls heart beat.
Glossary
• Heart- The heart is divided into four
chambers: right atrium, right ventricle, left
atrium, left ventricle. It acts as a pump to
move blood and nutrients around the body
YouTube Clip
• Circulatory System
http://www.youtube.com/watch?v=D3ZDJgFDdk
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Getting the Blood around the body
• How do we do this? What is involved?
• There are three varieties of blood vessels:
arteries, veins, and capillaries.
• During blood circulation, the arteries carry
blood away from the heart.
• The capillaries connect the arteries to veins.
Finally, the veins carry the blood back to the
heart.
A VERY VERY long system
• If you took all of the blood vessels out of an
average child, and laid them out in one line,
the line would be over 96,000 km long!
• An adult's vessels would be closer to 160,000
km long
Glossary
• Aorta- the largest artery leading out of the left
ventricle to the rest of the body.
• Vena Cava- The main veins that receive blood
from the rest of the body.
– Inferior: Drains lower body
– Superior : Drains head and arms.
Arteries
• Carry oxygenated blood away
from the heart
• An artery has three layers:
– an outer layer of tissue,
– a muscular middle,
– and an inner layer of epithelial
cells.
• The muscular wall of the
artery helps the heart pump
the blood.
Capillaries
• The capillaries are one epithelial
cell thick. RBC only pass through
them in single file.
• The exchange of oxygen and
carbon dioxide takes place
through the thin capillary wall.
• The tissue releases its waste
products, like carbon dioxide,
which pass through the wall and
into the red blood cells.
Veins
• Veins are similar to arteries but
transport blood at a lower pressure.
• Veins have three layers:
– an outer layer of tissue,
– muscle in the middle,
– and a smooth inner layer of epithelial
cells. However, the layers are thinner,
containing less tissue.
• Receive waste-rich blood from
capillaries and take it back to the lungs
and heart.
• Valves are like gates that only allow
blood to move in one direction.
Valves
Glossary
• Arteries- Are thick walled blood vessels that
transport oxygenated blood from the heart to
the body
• Capillaries- blood vessels that connect the
arteries to tissues, then tissues to the veins.
Very thin, only 1 RBC thick.
• Veins- blood vessels with thinner walls and
valves that take blood to the heart.
• Valves- allow blood flow in one direction only.
Getting Oxygen into the Blood Stream
1. Air Passes into
the lungs through
the nose and mouth
4. Each bronchus
divides into smaller
tubes called
Bronchioles.
2. Travels past the
throat and larynx into
the trachea
3. Trachea branches
into two bronchi,
which lead to the
lungs
5. Each bronchiole
ends in a cluster of
tiny air sacs called
alveoli
Getting Oxygen into the Blood stream
6. Gas exchange
occurs at the
Alveoli. 700 million
alveoli in the lungs
give a surface area
of approximately
the size of a tennis
court.
8. The thin wall of the
alveolar cell and the one
cell thick capillary wall
separate the two.
7. Each alveolus has a
network of capillaries
around it.
9. The distance between
the alveolar and a RBC is
less than 1 micrometre, so
gas exchange is very easy.
Controlling Breathing
• Note. Breathing is
controlled by the
movements of the ribs and
the diaphragm.
-Inhalation; Muscles lift
ribs upwards and outwards
-while the muscular
diaphragm contracts and
moves downwards.
-This increases the
volume of the chest cavity
Controlling Breathing
• The reverse happens
for exhalation
– Ribs come
downwards and
inwards
– Diaphragm expands
and moves upwards
– Decreasing volume of
chest cavity
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Capillaries of
head and
forelimbs
Anterior
vena cava
Pulmonary
artery
Aorta
Pulmonary
artery
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6
Capillaries
of right lung
Capillaries
of left lung
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4
3
3
11
Pulmonary
vein
5
Left atrium
Pulmonary
vein
1
Right atrium
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Left ventricle
Right ventricle
Aorta
Posterior
vena cava
8
Capillaries of
abdominal organs
and hind limbs
YouTube
• Circulatory Song
http://www.youtube.com/watch?v=q0s1MC1hcE