SECTION 1.1.2f
LESSON TWENTY ONE
THE CARDIOVASCULAR SYSTEM
1.2.2a:Understand the immediate and short-term effects of exercise
and physical activity on the cv system
1.2.2b : Understand the long-term effects of exercise and physical
activity on the cv system
LESSON OBJECTIVES
•WALT
1.2.2a:Understand the immediate and short-term
effects of exercise and physical activity on the
cv system
1.2.2b : Understand the long-term effects of
exercise and physical activity on the cv system
LESSON OUTCOMES
•
All of you – will understand the immediate and short-term effects of
exercise and physical activity on the cv system and the long-term effects
of exercise and physical activity on the cv system
•
Most of you– will understand the immediate and short-term effects of
exercise and physical activity on the cv system and the long-term effects
of exercise and physical activity on the cv system
and be able to answer exam questions/complete worksheets with help
from teacher
Some of you
- – will understand the immediate and short-term effects of exercise and
physical activity on the cv system and the long-term effects of exercise
and physical activity on the cv system
and be able to answer exam questions/complete worksheets
independently.
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The cardiovascular system
The heart is a muscular pump that pumps blood away from
the heart around the body through a system of arteries
which take oxygen rich blood and nutrients to the
muscles to allow them to work
Blood then picks up CO2 as a waste product from the
muscles and carries this back to the heart in veins. From
there it is pumped to the lungs where it is breathed out
and in exchange O2 is breathed in = gaseous exchange.
This happens because muscles need energy in the form of
O2 and nutrients to produce movement. CO2 is produced
when we exercise.
The CV system helps us get rid of waste products and
supplies muscles with the O2 and nutrients needed to
keep working
•When exercising muscles need more O2 - so the
heart needs to beat stronger and quicker
•Heart rate rises because of adrenaline
•This means more blood is pumped to the lungs so that
more O2 and nutrients can be circulated and waste
removed
•Training helps body to cope better when exercising
•A fit person has a bigger and stronger heart
Definitions
What are blood
pressure, cardiac
output, heart rate,
stroke volume ?
answer
• Blood pressure = the force exerted
by circulating blood on the walls of the
blood vessels
• Cardiac output= the amount of blood
ejected from the heart in one minute
• Heart rate = the number of times the
heart beats per minute
• Stroke volume = the volume of
blood pumped out of the heart by each
ventricle during one contraction
• THE IMMEDIATE AND SHORT
TERM EFFECTS OF
PARTICIPATION IN EXERCISE
AND PHYSICAL ACTIVITY ON THE
CV SYSTEM
BLOOD PRESSURE
The heart beats more strongly during
exercise, causing blood pressure
(bp)to rise.
BP has 2 parts
• Systolic = high pressure
measured when blood is pumped
out of heart – this number is
higher when exercising
• Diastolic =pressure when heart
relaxes between beats – the lower
number
Effects of regular exercise on
the cv system
Regular exercise
cv system
becomes stronger. Changes are:
• Stroke volume increases
• Heart Rate increase
• Cardiac output increases
Heart rate x stroke volume = cardiac
output
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Blood pressure increase
Blood is shunted to the working muscles
Digestive system are by-passed by the blood
Oxygen and Haemoglobin (Oxyhaemoglobin)
combine and are transported to the working
muscles.
Amount of exercise influences the heart rate
Cardiac centre controls and regulates the heart
rate
Blood vessels dilate at skin surface, to release
heat, causing skin to redden
Waste products such as salt and water exit body
via pores and capillaries at skin surface (sweat)
The endothelium (internal space of arteries) of
arteries automatically widens to let more blood
through.
DIET – CHOLESTEROL
HIGH CHOLESTEROL LEVELS CAN INCREASE THE RISK OF CHD
CHOLESTEROL = Fatty substance carried in blood by lipoproteins
HDL ( High density lipoprotein )
LDL (Low density lipoprotein )
HDL = good cholesterol because it takes cholesterol away from blood
vessels.
LDL = bad cholesterol – builds up in arteries, makes them less flexible
and more difficult for blood to pass through – so heart attack or
stroke can occur.
Combination of high blood pressure and high blood pressure = risk of
heart attack/stroke
REST
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REST and RECOVERY are 2
principles of training that
allow body to adapt to
training.
The same applies to the CV
system as rest allows the
heart to increase in size and
the number of capillaries to
increase
Recreational drugs.
NICOTINE – found in tobacco
Smoking increases heart rate and BP – which leads to
high blood pressure
Nicotine also reduces amount of HDL – so smoking
combined with diet high in LDL – higher risk of heart
disease.
ALCOHOL – drinking too much causes high blood
pressure.
Complete past paper questions
http://www.bhf.org.uk/heart-health/conditions/high-blood-pressure.aspx