Transcript Circulatory System & Diet

Circulatory System & Diet
D. Crowley, 2007
Monday, April 11, 2016
Circulatory System & Diet
• To know how a healthy circulatory system works, and how
a poor diet can affect it
Circulatory System
• Match the circulatory
key words with their
function
Circulatory System
• What is the function of the circulatory system? What parts
make it?
• The circulatory system is the body's main transport system,
carrying food and oxygen to the cells and taking waste
products (carbon dioxide) away
• It consists of the heart; arteries; veins; and
capillaries
Circulatory System
Heart
• The heart pumps blood around the body – in humans this is
a four chambered pump
• The right side of the heart pumps deoxygenated blood to the
lungs to pick up oxygen
• The left side of the heart pumps the oxygenated blood from
the lungs around the rest of the body (which is why it is
more muscular)
Arteries
Blood is carried by three different types of vessel
• Arteries are thick-walled muscular tubes which carry blood
away from the heart - fast flowing!
Veins
Blood is carried by three different types of vessel
• Veins are thin walled tubes which carry blood back to the
heart – they have a large diameter and valves as the blood
flows slower
Capillaries
Blood is carried by three different types of vessel
• Capillaries are extremely narrow tubes which carry blood
through our tissues: their walls are just one cell thick - so
thin that oxygen, food and waste products can easily pass
through them
Blood
• Blood is a liquid tissue whose function is to fight disease
and to transport materials around the body
• It consists of a straw coloured liquid called plasma, with red
blood cells, white blood cells and platelets
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Blood plasma (liquid) containing glucose, amino acids, nutrients, hormones, as well as waste materials like urea
Red blood cells contain haemoglobin, a protein which picks up oxygen molecules in the lungs
White blood cells fight disease by making antibodies and fighting germs
Platelets are cell fragments. Together with fibrinogen they form clots to repair cuts or tears in nearby tissue
Worksheet
• Complete the circulatory
system worksheet
Arteries
Heart
Veins
Capillaries
One cell thick
Problems
• Poor diet can affect our circulatory system in a variety of ways
• Brainstorm what else you think affects the circulatory system (what
is heart disease)?
• Explain in your own words how and why the circulatory system
gets affected
Problems
• Heart disease occurs when some of the heart muscle cells die. It is
often caused by a build up of fatty substances inside the arteries
(arteriosclerosis)
• This fatty material reduces the amount of blood which can get to the
heart muscle tissue
• Smoking, drinking, lack of exercise and poor diet can all increase
the likelihood of heart disease: a complete blockage leads to a heart
attack (smoking constricts the blood vessels)
• Exercise can help - it strengthens the heart muscle tissue and
improves circulation and blood flow
Out Of Breath
• People who are unfit tend to get out of breath much quicker
than a healthy person - why is this?
• If a person is unfit their heart is not as muscular as a fit
persons - this means it needs to work harder to pump blood
around the body
• After exercise the heart will be working very hard, but if the
arteries are clogged with excess cholesterol then not enough
blood (containing oxygen) can get around the body
• This means the person’s cells will not be getting enough
oxygen to function - which can be life threatening (hence if
you are unfit you breathe harder and faster than a fit person
after some exercise)