STEP-BY-STEP GCSE PE ©STEP-BY-STEP GCSE PE ©

Chapter content:

1. How the cardiovascular system works

2. A healthy active lifestyle and the cardiovascular system

• The immediate and short-term effects of participation in exercise and physical activity

• The long-term effects of participation in exercise and physical activity

• The importance of rest in-between exercise sessions

• The effects of diet on the circulatory system

• The effects of recreational drugs on the circulatory system

Second edition

A healthy, active lifestyle and A healthy, active lifestyle and your cardiovascular systemyour cardiovascular system

SECTION 1.2 Your healthy, active bodyYour healthy, active body

1.2.2 1.2.2

p.80

There are three components to the circulatory / cardiovascular system:

The heart

The main function of the circulatory system is transportation.

• It carries blood from the heart to all the cells of the body to provide them with food and oxygen.

• It carries waste products, including carbon dioxide, away from the cells to the lungs so that oxygen and carbon dioxide can be exchanged.

• How the cardiovascular system worksHow the cardiovascular system works11

The blood The blood vessels

p.80

Humans have a double circulation

When a blood cell travels through the circulatory system it goes through the heart twice. This is known as double circulation. This occurs because there are two circuits for the blood to travel through:

1 The systemic circuit (Takes blood around the body)

• It carries oxygenated blood around the body via the arteries, reacting with glucose in foods to release energy in the muscles.

• It then carries deoxygenated blood back to the heart along the veins – this is then pumped through the second circuit.

• The pulmonary circuit (Takes blood to the lungs)

• It carries deoxygenated blood from the heart to the lungs to be oxygenated.

• The oxygenated blood then travels back to the heart along the veins to re-start the process in the systemic circuit.

p.80

An analogy of how the circulatory system works A red football

leaves Anfield, the home of Liverpool F.C.

It enters Wembley (the heart of English football) and leaves red because Wembley is a neutral venue

The red football enters Goodison Park, the home of Everton F.C.

The football leaves blue

It enters Wembley and leaves blue

because Wembley is a neutral venue

The blue football enters Anfield

p.81

Vein (pulmonary vein)

Artery (pulmonary

artery)

OXYGENATED BLOOD

Transported through arteries (except

pulmonary artery)

DEOXYGENATED BLOOD

Transported through veins (except pulmonary vein)

PULMONARY CIRCUIT

SYSTEMIC CIRCUIT

The circulatory system in more detail

Artery (aorta)

Vein (vena cava)

p.82

How blood is pumped around the body

Below is a simple plan of the circulatory system:

Blood flows around the body in a ‘figure of eight’ circuit. It passes through the heart twice on each circuit.

Label the arteries and veins on the diagram:

Blood travels AWAY from the heart through ARTERIES. ( A )Blood travels BACK to the heart through VEINS. ( V )

Label the 2 separate ‘loops’ to the circuit:The top loop carries blood from the heart to the LUNGS and back. (Pulmonary Circuit) The bottom loop carries blood from the heart around the BODY and back. (Systemic Circuit)

Complete this key:

STUDENT TASKV

V

A

A

OxygenatedDeoxygenated

Systemic

Pulmonary

p.83

The heart in more detail

• The heart is made up of cardiac muscle. Its function is to act as a pump for blood.

• The heart contains four hollow chambers.• The top two chambers are called atria (where the blood enters the heart).• The bottom chambers are called ventricles (where the blood leaves the heart).

RIGHT ATRIUM LEFT

ATRIUM

RIGHT VENTRICL

E

LEFT VENTRICL

E

CARDIAC MUSCLE

p.84

1 Colour in both sides of the heart to represent oxygenated and deoxygenated blood.2 Label the four chambers of the heart.3 Using arrows draw the direction of the blood flow.4 Label the entries and exits of the heart with one of the following:

Blood flowing: To lungs From lungs To body From body

RIGHT ATRIUM

RIGHT VENTRICL

E

LEFT VENTRICL

E

From lungs

To bodyTo lungsFrom body

STUDENT TASK:

p.85

Important parts of the heart

The function of the labelled parts:THE SEPTUM – Divides the two sides of the heart preventing oxygenated blood

mixing with deoxygenated blood.THE PULMONARY VEIN – Transports oxygenated blood to the heart.THE AORTA – Transports oxygenated blood away from the heart to the body.THE VENA CAVA – Transports deoxygenated blood from the body back to the heart.THE PULMONARY ARTERY – Transports deoxygenated blood to the lungs.

AORTAPULMONARY VEIN

PULMONARY ARTERY

VENA CAVA

SEPTUM

p.86

How the heart pumps blood

The heart is divided into two sides. Each side is a pump. Consequently, the heart is a double pump.

THE RIGHT SIDE – Receives deoxygenated blood from the body and pumps it to the lungs to be oxygenated.

THE LEFT SIDE – Receives oxygenated blood from the lungs and pumps it to the rest of the body.

p.87

The cardiac cycle

The heart relaxes

allowing both sides to fill

with blood from the veins

The atria contract

forcing blood into the ventricles

The ventricles contract

forcing blood out of the heart into the

arteries

Stage 1 Stage 2

1 2 3

Stage 3

p.87

STUDENT TASK: Use the diagram below to describe in detail how blood moves around the body.

The blood leaves the right side of the heart through the pulmonary

artery to the lungs where it is

oxygenated.

After being used by the body the blood becomes

deoxygenated and returns to the heart

through the vena cava.

The blood travels back to the left side of the

heart through the pulmonabbbry vein.

Oxygenated blood is pumped out of the heart and around the body via

the aorta.

Pulmonary artery

x xwsxwxwx

w

The blood leaves the right side of the heart through the pulmonary

artery to the lungs where it is

oxygenated.

Lungs The blood travels back to the left

side of the heart through the

pulmonary vein.Aorta

Vena cava

Pulmonary vein

After being used by the body the blood becomes

deoxygenated and returns to the heart

through the vena cava.

Oxygenated blood is pumped out of the heart and around the body via the

aorta.

Pulmonary artery

Heart

Body

p.88

Valves in the heart

Valves within the heart separate the upper and lower chambers. This allows blood flow in one direction only, preventing back flow.

SEMI-LUNAR VALVES

BICUPSPID (MITRAL) VALVE

TRICUPSPID VALVE

p.89

Blood vessels

Blood moves around the body in blood vessels. There are three types of blood vessel.

Arteries• Carry blood away from the heart.• Carry oxygenated blood.

(Except the pulmonary artery)• They have thick elastic muscular walls.• They contain no valves.• They have small lumen (inner space).

Veins• Carry blood back to the heart.• Carry deoxygenated blood.

(Except the pulmonary vein)• They have thin muscular walls.• They contain valves.• They have large lumen.

Capillaries• Connect arteries to veins.• Carry food and oxygen direct to the

tissues.• Take waste away from the tissues.• They are microscopic in size.

BLOOD

ArteryVein

Wall of capillaries

Valve

BLOOD

p.90

Blood is composed of three different types of cells and a fluid known as plasma, which is mainly made up of water and gives the blood its liquid appearance.

1 Red blood cellsCarry oxygen around the body in red haemoglobin.

The composition of blood

2 White blood cellsFight against infection.

3 PlateletsWhen the skin is broken they clot the blood.

p.91

The pulse rate

• A pulse is caused by the heart as it pumps blood around the body.

• The pulse can be felt every time the heart beats because the artery walls expand and then contract.

• The pulse can be measured wherever an artery passes close to the surface of the skin, these areas are known as pulse rate points.

p.91

1 Insert the correct names for the valves within the heart on the diagram below: (3 marks)

2 What is the purpose of valves within the heart? (1 mark)

3 How does the blood on both sides of the heart manage to get through the valves? (2 marks)

Semi-lunar valves

Tricuspid valve Bicuspid (mitral) valve

To allow blood to flow in one direction only, preventing backflow.

The atria contract and then the ventricles contract. Each time forcing blood through the valves.

STUDENT QUESTIONSp.92

4 State whether the following statements apply to arteries or veins: (7 marks)

a) Usually carry oxygenated blood –

b) Usually carry deoxygenated blood –

c) Have thick walls –

d) Work under low pressure –

e) Contain valves –

f) Blood is carried towards the heart in the -

g) Blood is carried away from the heart in the -

5 Capillaries are the third type of blood vessel and are connected to both veins and arteries. What is their function? (2 marks)

6 Blood contains four major components. Complete this table by listing these components correctly. (4 marks)

To carry food and oxygen to the tissues and take the waste away from them.

ACTION COMPONENT

Fight infection

Help clotting

Carry oxygen

Transport substances

Arteries

Arteries

Arteries.

Veins

Veins

Veins

Veins.

White blood cells

Platelets

Red blood cells

Plasma

Total marks /24

7. Complete the following sentences: (5 marks)

i) A pulse is caused -

ii) The pulse can be felt due to the -

iii) The pulse can be measured at –

iv) When we exercise the pulse rate -

v) This enables more oxygen to be -

By the heart as it pumps blood around the body

Artery walls expanding and contracting

Pulse rate points

Speeds up

Delivered to working muscles

p.93

• A healthy active lifestyle and the A healthy active lifestyle and the cardiovascular systemcardiovascular system

22p.94

The immediate and short-term effects of participation in exercise and physical activity

Heart rate increases

Blood pressure increases

Blood vessels expand at skin

surface, to release heat,

causing the skin to redden

Blood is shunted to the working

muscles

The amount of exercise

influences the heart rate

Waste products water and salt

exit the body via pores at skin

surface

Arteries widen automatically to let more blood

through

Heart rate

• The heart rate is the number of times the heart beats per minute.

• A normal resting heart rate is between 60 – 80 beats per minute.

• Oxygen and nutrients are carried to the muscles by the blood. During exercise the muscles require more oxygen and nutrients so the heart has to pump faster, increasing the heart rate.

p.94

Blood pressure

• Blood pressure is a measurement of how much pressure the blood flowing through an artery puts on the artery wall.

• When exercise begins, blood pressure increases. This increases blood flow to meet the demand of the working muscles.

• Systolic blood pressure is caused by blood being forced into the arteries by the contraction of the left ventricle.

p.95

• Diastolic blood pressure is caused by the left ventricle relaxing once blood has entered it via the atrium. At this point the arteries relax allowing a reading of their elasticity which indicates the vessel’s quality.

p.95

• A blood pressure reading can range from between 100 over 60 and 140 over 90 for an average person.

The long-term effects of participation in exercise and physical activity

Decreased resting heart

rate Faster recovery from exercise

Stroke volume increases

Heart increases in size

Reduces risk of coronary heart

disease

Reduced blood pressure

Healthy veins and arteries

Oxygen delivered to the working muscles more effectively

Cardiac output increases

p.96

The benefits of regular exercise on the cardiovascular system

p.96

Resting heart rate

• Resting heart rate gives an indication of fitness.

• Regular exercise increases the size and strength of the heart, allowing it to supply the same amount of blood with fewer beats.

• Regular exercise can decrease the resting heart rate.

Heart recovery rate

• Heart rate recovery is the rate at which the heart returns to its normal state after exercise.

• The faster the recovery rate the better the level of cardiovascular fitness.

• Regular exercise can increase the heart recovery rate.

p.97

Stroke volume

• Stroke volume is the amount of blood pumped out of the heart with each beat.

• Regular exercise will increase the stroke volume both at rest and at work.

This is due to the heart becoming stronger and more efficient.

• At rest the heart pumps about 85ml of blood. During exercise this could increase to 130ml.

Cardiac output

• Cardiac output is the amount of blood ejected by the heart per minute.

• Cardiac output (CO) = Stroke volume (SV) x Heart rate (HR)

• The changes that take place to stroke volume and heart rate through regular exercise affect the cardiac output.

p.97

Blood pressure

• Blood pressure is used as an indication of how fit the circulatory system is.

• High blood pressure can lead to angina, heart attacks and strokes.

• Blood pressure can be affected by four main factors:1 AGE – it generally increases with age.2 GENDER – it is generally higher in men.3 EXERCISE – it increases in the short-term but reduces in the long-term.4 STRESS – increases blood pressure.

• Regular exercise can reduce blood pressure.

A patient has her blood pressure taken by a doctor

Veins and arteries

• Regular exercise can increase the number of capillaries within the heart.

• Regular exercise improves the flexibility and efficiency of blood vessels, reducing the risk of coronary heart disease (CHD).

p.98

The importance of rest in-between exercise sessions

• In order to improve cardiovascular fitness levels the cardiovascular system needs to be put under increased stress from exercise.

• Rest is essential after exercise sessions in order to maximise the effect of training.

• Rest allows the heart to grow in size and thickness and the number of capillaries to increase.

p.98

The effects of diet on the circulatory system

• Diet can affect blood pressure and cholesterol.

• A diet low in fat, salt and sugar but high in fruit and vegetables can help to reduce the risk of high blood pressure.

• Including omega 3 essential fatty acids in a diet can help to keep the blood from clotting.

• Cholesterol is a fatty substance carried in the blood by lipoproteins, which come in two forms:

1 Low density lipoprotein (LDL) ‘BAD CHOLESTEROL’Consists mainly of FAT and can cause deposits, called ‘PLAQUE’, to build up inthe arteries which restrict blood flow. This can raise blood pressure and increase the risk of heart problems.

2 High density lipoprotein (HDL) ‘GOOD CHOLESTEROL’Consists mainly of protein with small amounts of fat. It helps reduce the amount of cholesterol building up in the arteries.

• Reducing the intake of animal fats and salt and increasing the intake of fibre, fruit and vegetables will help to control cholesterol levels.

p.98

The effects of recreational drugs on the circulatory system

• Smoking cigarettes, which contain the drug nicotine, releases adrenaline which constricts the arteries increasing the heart rate and raising blood pressure.

• Smoking lowers HDL cholesterol which increases the chance of blocked arteries.

• Smoke contains carbon monoxide which reduces the red blood cells’ ability to transport oxygen. This has an impact on fitness levels.

• Alcohol in moderation can increase HDL which can lead to lower blood pressure.

• Alcohol in excess can be detrimental to blood circulation.

p.99

John Daly has struggled with diet, smoking and alcohol problems throughout his golfing career

p.99

3 Why is rest important in-between exercise sessions? (1 mark)

4 What effect does drinking alcohol have on blood pressure? (1 mark)

5 Identify five immediate and short-term effects of exercise on the cardiovascular system. (5 marks)

6 Identify five long-term benefits of regular exercise on the cardiovascular system. (5 marks)

Total marks /14

STUDENT QUESTIONS

The amount of blood shunted to working musclesThe amount of blood ejected by the heart per minuteThe number of times the heartbeats per minuteThe amount of blood pumped out of the heart with each beat

The number of times the heart beats per minuteThe amount of blood ejected by the heart per minuteThe amount of blood pumped out of the heart with each beatThe amount of blood shunted to working muscles

1 Cardiac output is: (1) 2 Stroke volume is: (1)

X

X

To maximise the effect of training, to allow the heart to grow and to let the number of capillaries increase

It raises blood pressure

Heart rate increases; Blood pressure increases; Blood vessels expand at skin surface, to release heat, causing the skin to redden; Blood is shunted to the working muscles; The amount of exercise influences the heart rate; Waste products water and salt exit the body via pores at skin surface; arteries widen automatically to let more blood through

Decreased resting heart rate; Faster recovery from exercise; Stroke volume increases; Heart increases in size; Reduces risk of coronary heart disease; Blood pressure reduced; Healthy veins and arteries; Oxygen delivered to the working muscles more effectively; Cardiac output increases

A

B

C

D

A

B

C

D