Circulatory System & Diet

D. Crowley, 2007

Circulatory System & Diet• To know how a healthy circulatory system works, and how

a poor diet can affect it

Wednesday, April 19, 2023

Circulatory System• Match the circulatory

key words with their function

• It consists of the heart; arteries; veins; and capillaries

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

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!

VeinsBlood 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

• 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)