Download The Human Heart

Our Body System will be the Circulation System
The circulatory system is responsible
for pumping ______
blood around the body.
We need blood to be taken around the
oxygen
body because blood contains ________
glucose These are needed so
and _______.
cells in our bodies can
that all the ____
energy through _________.
respiration
produce _____
The main organs in the circulatory system
heart the lungs and the kidneys.
are the _____,
Words – energy, heart, blood, glucose,
respiration, oxygen, cells
Fascinating Facts!

It is about the size of a fist.


It beats on average 70 times per minute.
That’s 4200 per hour.
Approximately one hundred thousand
beats per day.
 365 million beats per year.


About 30 billion beats in an average life
time of 80 years.
Fascinating Facts!

An adult heart pumps 7,500 litres of blood
daily.

It takes 20 seconds to pump blood to every
cell in your body.

Blood is cleaned by the kidneys.

If you lined up all the blood vessels in
your body end to end, they would wrap
around the earth twice!
The Heart
 There
is one muscle in your body
that is vital for your survival... The
Heart.
 The
heart is a involuntary muscle.
This means it works on its own
without us having to think about
making it beat.
The Heart
 The
heart is responsible for two
things.
1. Through the blood it pumps, the heart
provides oxygen and nutrients to our
cells to keep us alive.
2. Carry away wastes from these active
cells to special organs that rid them
from our bodies.
The Heart
 The
heart has four different hollow
areas called chambers.
 There
are two chambers on each side
of the heart.
The Heart
 The
heart is actually two pumps in one.
 The
right side receives blood from the
body and pumps it to the lungs to get
oxygen.
 The
left side receives the oxygenated
blood from the lungs and pumps it
around the body.
The “Double Circulatory”
1.System
Deoxygenated
2. The blood
blood is pumped
from the heart to
the lungs
4. The oxygen
leaves the blood
to be used for
respiration in the
body and the
blood goes back
to the heart
receives oxygen
and is pumped back
to the heart
3. The oxygenated
blood is then
pumped to the rest
of the body
Label the lines on the diagram - words to use - left atrium
- left ventricle
- right atrium
- right ventricle
What’s our blood made of?
What’s our blood made of?
Blood is made of a clear liquid called plasma (blood is in
fact 55% plasma) and 3 types of cells (these make up the
other 45% of blood) these cells are:
White blood cells –
these help fight bugs
Red blood cells – the haemoglobin in these carry
the oxygen round our body
Platelets – these stop bleeding by forming clots.
Arteries, veins and capillaries
Arteries carry high pressure
blood away from the heart.
They have no valves and have
elastic walls that contract
Capillaries have thin walls
(one cell thick) to allow
glucose and oxygen to pass
through. Also used to
connect arteries to veins.
“Lumen”
Veins carry low pressure blood back to the
heart. They have thinner, less elastic walls and
have valves to prevent backflow of blood.
How blood gets back to the heart?

By veins under low pressure

The blood moves back to the heart
because of muscle contractions

Sometimes when we are not active for
a while (eg on long plane flights) our
muscles don’t contract and blood
pools in our legs

Remember veins are the only blood
vessels that have valves to stop
backflow
Blood Pressure (BP)
BP is the measurement of force applied
to the artery walls as the heart pumps
blood around the body.
Pressure is determined by the force,
the amount of blood pumped and the
size and flexibility of the arteries.
Blood Pressure Is Affected By:
•
•
•
•
•
•
•
•
Volume of blood
Size and condition of arteries
Volume of water in the body
Salt content in body-fluid shifts/osmosis
Condition of the kidneys
Nervous system control
Blood vessels-constriction/dilation
Various chemicals- eg Adrenaline
Normal Blood Pressure (BP)
• BP Should be <120/80 and if >140/90 is
considered Hypertension
• Changes in BP depending on age, activity,
temperature, posture, physical state,
emotional state and medication use
• BP is lowest when sleeping and rises as
you get up.
Hypotension
• Inadequate flow of blood to heart, brain,
kidneys and other vital organs
• Body will attempt to compensate with
raised HR,BP
• If not corrected the inadequate supply of
oxygen leads to changes in some organs
e.g. heart and kidneys and eventually
death
Your Task
 Write
up a flow chart that describes
the movement of blood through the
heart and it’s major vessels.
 Try
to make the flow chart into a
complete cycle.
Your Task
1.
Deoxygenated blood enters the
right atrium from the vena cava.
2.
It then passes through the trcuspid
valve and into the right ventricle.
Your Task
5.
Deoxygenated blood is then pumped
from the right ventricle to the lungs
by the pulmonary artery
6.
Oxygenated blood is then pumped
back to the left atrium
Your Task
7.
Blood is then pumped from the right
atrium through the mitral valve into
the left ventricle
8.
blood is then pumped from the left
ventricle to the body by the aorta
How does the heart keep us
healthy?
1. By supplying oxygen to the cells in our organs
2. It supplies glucose to our cells
(Remember the respiration reaction where:
glucose + oxygen react to form energy and the waste
products – carbon doxide and energy)
3. By removing waste products like CO2 ,water and heat
from our body
What does plasma have in it?

Nutrients eg Glucose
Parts of the blood and their function

Red blood cells – carry oxygen from the
lungs to the cells of the body
White blood cells swallow foreign bodies
Others produce antibodies which attach to
the foreign microbes and make them
inactive.(fight disease)
Platelets – cells that blood clot
Plasma – takes glucose to the cells and
CO2 away
Why does our heart beat faster
when we exercise?

Because our muscles need more
oxygen
How can we tell if someone is
fit?

by getting them to do exercise and
then timing how long it takes for their
heart rate to return to normal
Why do we have circular bones
in our trachea?

– to give it strength and flexibility
bones
Remember them from
our dissection?
How do we breath using our
diaphragm?
Look at your diagram
Arthrosclerosis (aka heart disease)

Is the narrowing of arteries (with
plaque build up) that supply the
heart muscle (coronary arteries)

Caused when to much fatty food is
eaten ,smoking and not enough
exercise
Respiration equation
glucose + oxygen
carbon + water + energy
dioxide
Why are there capillaries around
alveoli–
 Because
they are small and thin
to give large surface area for
gases to dissolve
Why are alveoli moist?
The
moisture dissolves oxygen
to helps with gas exchange
through the capilliary walls

Remember to learn your parts of the
heart and which way blood flows
through it

Why is the heart thicker on the left side?