Download The Heart!

• Every cell in your
body needs
oxygen to live.
The role of the
heart is to send
blood that is full
of oxygen to all
the cells in your
body.
• Blood has two major parts:
– 55% plasma
• 92%water
• 8% fats, proteins, ions, sugars,
amino acids and nitrogenous
waste
– 45% blood cells
• 99% red blood cells
• 1% platelets & white blood cells
• Plasma is the liquid portion of blood –
a protein-salt-sugar-fat, etc. solution
in which red and white blood cells and
platelets are suspended.
• Plasma also contains proteins:
– albumin (a protein needed to both
maintain growth and repair tissues),
– fibrinogen (clotting of blood)
– globulins (antibodies, which to identify
and neutralize foreign objects such as
bacteria and viruses).
• RBCs carry fresh oxygen throughout the body - gives
your blood its bright red color
• RBCs are round with a flattish, indented center (like
doughnuts without a hole)
• Hemoglobin is the protein inside RBCs that carries
oxygen.
• RBCs also remove carbon dioxide from your body,
transporting it to the lungs for you to exhale.
• RBCs are made inside your bones, in the bone marrow.
• RBCs typically live for about 120 days, and then they
die.
• Bone marrow is
the flexible tissue
in the interior of
bones.
• In humans, red
blood cells are
produced by
cores of bone
marrow
• WBCs account for only about 1% of your blood
– Also called leukocytes
• Your immunity cells; flow through your
bloodstream to battle viruses, bacteria, and
other foreign invaders that threaten your
health
• Produced inside the bone marrow; stored in
your blood and lymphatic tissues
• Lifespan of 1-3 days; bone marrow is constantly
producing them
• Monocytes. They have a longer lifespan than many white
blood cells and help to break down bacteria.
• Lymphocytes. They create antibodies to defend against
bacteria, viruses, and other potentially harmful invaders.
• Neutrophils. They kill and digest bacteria and fungi. They
are the most numerous type of white blood cell and your
first line of defense when infection strikes.
• Basophils. These small cells appear to sound an alarm
when infectious agents invade your blood. They secrete
chemicals such as histamine, a marker of allergic disease,
that help control the body's immune response.
• Eosinophils. They attack and kill parasites, destroy cancer
cells, and help with allergic responses.
• Not actually cells (small fragments of cells)
• Help the clotting process (or coagulation);
gather at the site of an injury, stick to the lining
of the injured blood vessel, and form a platform
on which blood coagulation can occur – a scab!
– A higher than normal number of platelets can cause
unnecessary clotting, which can lead to strokes and
heart attacks
– Too few platelets can lead to extensive bleeding
• You will now make 250 grams of "blood.”
• Today you will use weight instead of volume
because the materials you will use are
granular solids with air spaces between the
grains.
– A true volume cannot be found by simply
putting the materials in a graduated cylinder
• There are 8 different blood types
• Red Blood Cells (RBCs) determine
what blood type a person has
based on what type of antigens are
present on the surface of these red
blood cells…What are antigens?
–Let’s read about it!
• Take a look at the handout on blood
disorders and diseases…
• Now it’s your turn to do the teaching!
1. The passageways
that carry this blood
are called blood
vessels.
1. The passageways
that carry this blood
are called blood
vessels
2. Arteries carry
oxygen-rich blood to
the cells that need it
– The largest artery is
the aorta
1.
The passageways that carry this
blood are called blood vessels.
2. Arteries carry oxygen-rich blood
to the cells that need it.
– The largest artery is the aorta.
3. Veins carry blood back to the
heart again. It is pumped into
your lungs where it picks up
oxygen and then goes back to
your heart, from where it is
pumped back again into your
body.
1.
It only takes about 20 seconds to
pump blood to every cell of your
body.
• The human heart is a muscle that lies left of the
chest .
• It has about the size of a fist .
• The heart is like a pump that sends blood
around your body. The blood gives you the
oxygen you need .
• An average heart pumps about 70 milliliters of
blood into your body with every beat .
– That’s about 5 liters every minute or about 7200
liters every day.
• The heart is made up of 4 chambers
– Atria: the top two chambers
• These fill with blood
– Ventricles: bottom two chambers
• Their job is to squirt out the blood
– In the middle of the heart there is a thick
muscle called the septum that separates
the left and the right side
• The atria and ventricles work together. The atria fill
with blood and when they are full they let the
blood into the ventricles.
• When these ventricles pump the blood out of the
heart, the atria fill up again and the whole process
starts again.
• There are four valves in the heart
that make sure that the blood is
pumped in the right direction.
• When the heart contracts , it
pumps blood from its chambers
into the body.
• Then the heart muscle relaxes
and lets the chambers fill up.
• Valves are flap-like structures that allow
blood to flow in one direction.
• Prevents the back flow of blood as it is
pumped.
•
•
•
•
The tricuspid valve
The pulmonary valve
The mitral valve
The aortic valve
1. The veins of the body all eventually drain into
the right atrium
2. Once the right atrium is full, the tricuspid valve
opens, allowing the de-saturated blood to flow
into the right ventricle
– De-saturated = no oxygen
3. The right ventricle then fills with the desaturated blood.
– As the pressures begin to change in the right
atrium and right ventricle, the tricuspid valve
closes.
• As the de-saturated blood leaves the right
ventricle, it passes through the pulmonary
valve, which has been closed as the right
ventricle was filling.
• The pulmonary valve opens, allowing the blood
to leave the right ventricle and flow to the
lungs via the pulmonary artery.
• Once the right ventricle has emptied, the
pulmonary valve closes, thereby keeping the
blood from re-entering the right ventricle.
• As the de-saturated blood passes through
the lungs, the carbon dioxide that was
added to the red blood cells by the body’s
organs is exchanged for a new supply of
oxygen.
• The newly oxygenated blood then flows
from the lungs to the left atrium, which is
the receiving chamber on the left side of the
heart.
• The valve located in the left atrium is the mitral valve.
• As the left atrium fills with the newly oxygenated
blood, the mitral valve remains closed.
• As the pressure changes within the left atrium and
left ventricle, the mitral valve opens, allowing the
oxygenated blood to flow into the left ventricle.
• As the left ventricle fills, the pressures in the left
atrium and left ventricle begin to change.
• Once the left ventricle is filled, the mitral valve closes
as the left ventricle begins to contract.
• By closing at this time, the mitral valve prevents the
oxygenated blood in the left ventricle from flowing
back to the lungs.
• The left ventricle is the
pumping chamber of the
left side of the heart and
is the most muscular
portion of the heart.
– When you hear some say
their blood pressure is 120
over 80, it is the left
ventricle that is generating
these pressures.
• As the left ventricle contracts, the oxygenated
blood leaves the heart and crosses the aortic
valve, which is the valve that helps to control
the flow of blood out of the heart to the body.
• The oxygenated blood leaving the left ventricle
and crossing the aortic valve enters the main
artery of the body, known as the aorta.
• The aorta then travels to the body’s organs via
branches that carry the blood to the individual
organs.
Put It All Together Now…
• The amount of pressure on one’s
arteries every time the hear beats.
• Systolic Pressure – the first number
– The amount of pressure on the arteries
when the heart beats
• Diastolic Pressure – the second
number
– The pressure on the hearties when the
heart is NOT beating
• Average blood pressure readings for
teenagers is 100/60
• High Blood Pressure
– A sign that the heart is working harder than it
should to push the blood through the blood
vessels
• Reading is 140/90 or over
• Leads to enlargement of the main pumping chamber
of the heart (the left ventricle) and overtaxing the
heart
– Stroke, eye damage, blood clots & aneurysm, heart
attack/failure, kidney damage
• Risk factors – overweight, eating a diet high in
sodium, smoking, stress, lack of exercise, family
history, age
Hypertension
• Low Blood Pressure
– May be a sign of good health and a decreased
risk of heart disease, but in some people,
hypotension can be a problem
• Can result in a decreased supply of oxygen and
nutrients to your brain, which can eventually lead to
life-threatening shock, damaging your brain or heart
• Reading is under 90/60