Download A and P lesson 7 - Calthorpe Park Moodle

GCSE
PE
Lesson 7:
Cardiac Cycle and
Cardiac Output
5/2/2017
Starter activity
Collect a card that describes the
function of the cardio-respiratory
system
Work as a class to line yourselves
around the room in order
Learning
Challenges
➔ Understand the cardiac cycle and how
this relates to blood pressure
➔ Understand how to calculate cardiac
output
➔ Understand how cardiac output
responds to exercise
Activity 1: Cardiac cycle
Practise taking your blood pressure
(do not worry about your actual
reading – several factors can affect
blood pressure readings)
What is happening to the heart during
the systolic (higher top reading) and
diastolic (lower bottom reading)
10
phases?
Which of the heart’s chambers is
responsible for this?
Extension
Create an analogy to
help you to
remember the
cardiac cycle.
You might want to
consider inflating a
balloon, tyre or hose
pipe
minutes
Cardiac cycle and blood pressure
When you measured your blood pressure you
were given two readings
The systolic phase occurs when the heart
contracts and squeezes blood into the arteries.
Eg. 120/80
This causes high pressure in the arteries, hence
the higher figure on your blood pressure reading
The top figure is the systolic measurement
The bottom figure is the diastolic measurement
The diastolic phase occurs when the heart
relaxes and its chambers fill with blood.
This results in lower pressure in the arteries,
hence the lower reading on your blood pressure
reading.
One contraction and relaxation of the heart is
known as a cardiac cycle
Extension
Activity 2: Cardiac output
Can your stroke
volume change?
Explain…
Practical activity
Using an average stroke volume of 60ml per beat, calculate your
cardiac output at rest
Participate in a short bout of vigorous activity
How has your cardiac output changed?
Why?
10 minutes
Cardiac output (Q)
= Stroke volume
(SV) x Heart rate
(HR)
Activity 3: Why might this have
happened to Chris O’Hare after a race?
• Use the textbooks to research your
answer.
• Use as many relevant key terms
as possible.
10 minutes
Extension
Imagine that the
arteries do not
constrict and dilate,
how would this have
changed Chris’
performance?
Tip: You may want to
consider the digestive
system
Key terms
Diastole
The phase of the heartbeat when the chambers of the heart relax and fill with blood.
Systole
The phase of the heartbeat when the chambers of the heart contract and empty of
blood; when blood is ejected from the heart.
Cardiac cycle
One cycle of diastole and systole is one cardiac cycle.
Blood pressure
The pressure that blood is under. The systolic reading measures the pressure the blood
is under when the heart contracts. The diastolic reading measures the pressure the
blood is under when the heart relaxes.
Vasoconstriction
The narrowing of the internal diameter of a blood vessel to
decrease blood flow. The arteries constrict during exercise so
that less blood is delivered to inactive areas.
Vasodilation
The widening of the internal diameter of a blood vessel to
increase blood flow. The arteries dilate during exercise so that
more blood is delivered to active areas, increasing their oxygen
supply.
Exam tip
The heart is often
called a double
pump as it has two
circuits that
transport
oxygenated blood
and deoxygenated
blood.
Plenary
Learning
Challenges
Pyramid
Come up with a
question that no one
in the room can
answer about today’s
learning
Learning
Challenges
➔ Understand the cardiac cycle and how
this relates to blood pressure
➔ Understand how to calculate cardiac
output
➔ Understand how cardiac output
responds to exercise
Home Learning
● Next person in the register adds the
key terms to the Moodle glossary
● Complete worksheets 1.17 and 1.18
up to, but not including EPOC
● Remember the equations for aerobic
and anaerobic
● Provide examples of each type of
exercise