PHYSIOLOGY 1: The Heart
IB topic(s): 6.2, D.1 and D.4
Essential Idea(s): Internal and external factors influence heart function.
Lesson Topic
Days Statement(s) and Objective(s)
SKILLS/ Activities
1
1
TOK: symbols are used as a
form of non-verbal
communication. Why is the
heart used as a symbol for
love? What is the importance
of symbols in different areas of
knowledge.
Structure
6.2.S2: Recognition of the
chambers and valves of the
heart and the blood vessels
connected to it in dissected
hearts or in diagrams of heart
structure (Oxford Biology Course
Companion page 295).
 Label a diagram of the heart
with the following structure
names: superior vena cava,
inferior vena cava, pulmonary
semilunar valve, aorta,
pulmonary artery, pulmonary
veins, aortic semilunar valve,
left atrioventricular valve, left
ventricle, septum, right
ventricle, left atrium, right
atrium and right
atrioventricular valve.
6.2.U7: There is a separate
circulation for the lungs (Oxford
Biology Course Companion page
295).
 Draw a diagram to illustrate
the double circulation system
in mammals.
 Compare the circulation of
blood in fish to that of
mammals.
 Explain the flow of blood
through the pulmonary and
systemic circulations.
 Explain why the mammalian
heart must function as a double
pump.
2
Cardiac
Cycle
2
6.2.U6: Valves in veins and the
heart ensure circulation of blood
by preventing backflow (Oxford
Biology Course Companion page
294).
Utilization: understanding of
the structure of the
cardiovascular system has
allowed for the development
of heart surgery.
Aim 6: a heart dissection is
suggested as a means of
studying heart structure

Outline the structure and
function of a pocket valve.
D.4.U6: Normal heart sounds
are caused by the
atrioventricular valves and
semilunar valves closing causing
changes in blood flow (Oxford
Biology Course Companion page
688).
 State the cause of each of the
two sounds of the heartbeat.
D.4.NOS: Developments in
scientific research followed
improvements in apparatus or
instrumentation—the invention
of the stethoscope led to
improved knowledge of the
workings of the heart (Oxford
Biology Course Companion page
687).
 List variables that lead to the
development of the
stethoscope.
 State the function of the
stethoscope.
6.2.A3: Pressure changes in the
left atrium, left ventricle and
aorta during the cardiac cycle
(Oxford Biology Course Companion
page 300).
 Explain the pressure changes in
the left atrium, left ventricle
and aorta during the cardiac
cycle.
 Explain the relationship
between atrial and ventricular
pressure and the opening and
closing of heart valves.
 Explain the atrial, ventricular
and arterial pressure changes
as illustrated on a graph of
pressure changes during the
cardiac cycle.
 Identify the time of opening
and closing of heart valves on a
graph o f pressure changes
during the cardiac cycle.
3
Heart
Beat
2
6.2.U8: The heartbeat is
initiated by a group of
specialized muscle cells in the
right atrium called the sinoatrial
node (Oxford Biology Course
Companion page 298).
 Define myogenic contraction.
 Outline the role of cells in the
sinoatrial node.
6.2.U9: The sinoatrial node acts
as a pacemaker(Oxford Biology
Course Companion page 299).
 State the reason why the
sinoatrial node is often called
the pacemaker.
6.2.U10: The sinoatrial node
sends out an electrical signal
that stimulates contraction as it
is propagated through the walls
of the atria and then the walls of
the ventricles (Oxford Biology
Course Companion page 299).
 Describe the propagation of
the electrical signal from the
sinoatrial node through the
atria and ventricles.
D.4.U2: Signals from the
sinoatrial node that cause
contraction cannot pass directly
from atria to ventricles (Oxford
Biology Course Companion page
685).
 Explain the events of the
cardiac cycle, including atrial
and ventricular systole and
diastole and the movement of
the signal to contract through
the heart.
 Outline the role of the
atrioventricular node in the
cardiac cycle.
D.4.U3: There is a delay
between the arrival and passing
on of a stimulus at the
atrioventricular node (Oxford
Biology Course Companion page
686).
 Outline the causes of the
delayed initiation of
contraction of ventricles.
D.4.U4: This delay allows time
for atrial systole before the
atrioventricular valves close
(Oxford Biology Course Companion
page 687).
 State the function of a delayed
contraction of the ventricle.
D.4.U5: Conducting fibres
ensure coordinated contraction
of the entire ventricle wall
(Oxford Biology Course Companion
page 687).
 Describe the motion of the
signal to contract from the AV
node through the ventricles.
 List features of Purkinje fibers
that facilitate rapid conduction
of the contraction signal
through the ventricle.
 State that the contraction of
the ventricle begins at the
heart apex.
D.4.S3: Mapping of the cardiac
cycle to a normal ECG trace
(Oxford Biology Course Companion
page 689).
 State the function of an
electrocardiogram.
 Label the P, Q, R, S and T
waves on an ECG trace.
 State the cause of the P wave,
the QRS wave and the T wave.
 State an application of the use
of ECG technology.
D.4.A1: Use of artificial
pacemakers to regulate the
heart rate (Oxford Biology Course
Companion page 689).
 State the purpose of an
artificial pacemaker device.
D.4.A2: Use of defibrillation to
treat life-threatening cardiac
conditions (Oxford Biology Course
Companion page 690).
 State the cause and effect of
ventricular fibrillation.
 State the purpose of a
defibrillator.
D.4.U1: Structure of cardiac
muscle cells allows propagation
of stimuli through the heart
wall. (Oxford Biology Course
Companion page 685).
 Compare cardiac muscle tissue
to skeletal muscle tissue.
 Contrast cardiac muscle tissue
to skeletal muscle tissue.
 Describe how the Y-shape,
intercalated discs and gap
junctions of cardiac muscle
cells allow for propagation of
the stimulus to contract.
4
Heart
Rate
2
6.2.U11: The heart rate can be
increased or decreased by
impulses brought to the heart
through two nerves from the
medulla of the brain (Oxford
Biology Course Companion page
301).
 Outline the structures and


functions of nervous tissue
that can regulate heart rate.
Describe factors that will
increase heart rate.
Describe factors that will
decrease heart rate.
6.2.U12: Epinephrine increases
the heart rate to prepare for
vigorous physical activity(Oxford
Biology Course Companion page
302).
 Outline conditions that will
lead to epinephrine secretion.
 Explain the effect of
TOK: our current
understanding is that emotions
are the product of activity in
the brain rather than the
heart. Is knowledge based on
the science more valid than
knowledge based on intuition?
epinephrine on heart rate.
D.4.S1: Measurement and
interpretation of the heart rate
under different conditions
(Oxford Biology Course Companion
page 688).
 List variables that can influence
heart rate.
 Outline methods for detecting
heart rate.
5
Disease
1
Aim 8: the social implications
of coronary heart disease could
be discussed.
UNIT 2: The Circulatory System
IB topic(s): 6.2, 6.3, D.1 and D.4
Essential Idea(s): The blood system continuously transports substances to cells and
simultaneously collects waste products.
Lesson Topic
1
Double
circulation
Days Statement(s) and Objective(s)
6.2.A1: William Harvey’s discovery of the
circulation of the blood with the heart acting as
the pump (Oxford Biology Course Companion page
290).
 Outline William Harvey’s role in discovery of
blood circulation.
6.2.NOS: Theories are regarded as uncertainWilliam Harvey overturned theories developed by
the ancient Greek philosophy Galen on
movement of blood in the body (Oxford Biology
Course Companion page 290).
 Outline Galen’s description of blood flow in the
body.
 Describe how Harvey was able to disprove Galen’s
theory.
2
Arteries
6.2.U1: Arteries convey blood at high pressure
from the ventricles to the tissues of the body
(Oxford Biology Course Companion page 291).
 State the function of arteries.
 Outline the role of elastic and muscle tissue in
arteries.
 State the reason for toughness of artery walls.
6.2.U2: Arteries have muscle cells and elastic
fibres in their walls (Oxford Biology Course
Companion page 291).
 Describe the structure and function of the three
layers of artery wall tissue.
6.2.U3: The muscle and elastic fibres assist in
maintaining blood pressure between pump cycles
(Oxford Biology Course Companion page 292).
 Describe the mechanism used to maintain blood
flow in arteries between heartbeats.
 Define systolic and diastolic blood pressure.
 Define vasoconstriction and vasodilation.
6.2.S1: Identification of the blood vessels as
arteries, capillaries or veins from the structure of
their walls (Oxford Biology Course Companion page
Skills/
Activities
294).
 Compare the diameter, relative wall thickness,
lumen diameter, number of wall layers,
abundance of muscle and elastic fibres and
presence of valves in arteries, capillaries and
veins.
 Given a micrograph, identify a blood vessel as an
artery, capillary or vein.
3
Blood
pressure
D.4.S2: Interpretation of systolic and diastolic
blood pressure measurements (Oxford Biology
Course Companion page 691).
 State the cause of systolic and diastolic pressure.
 Describe how sound is used to measure blood
pressure.
4
Capillaries
6.2.U4: Blood flows through tissues in capillaries.
Capillaries have permeable walls that allow
exchange of materials between cells in the tissue
and the blood in the capillary (Oxford Biology
Course Companion page 293).
 Describe the structure and function of capillaries.
 Describe the cause and effect of diffusion of blood
plasma into and out of a capillary network.
6.2.S1: Identification of the blood vessels as
arteries, capillaries or veins from the structure of
their walls (Oxford Biology Course Companion page
294).
 Compare the diameter, relative wall thickness,
lumen diameter, number of wall layers,
abundance of muscle and elastic fibres and
presence of valves in arteries, capillaries and
veins.
 Given a micrograph, identify a blood vessel as an
artery, capillary or vein.
5
Veins
6.2.U5: Veins collect blood at low pressure from
the tissues of the body and return it to the atria of
the heart (Oxford Biology Course Companion page
293).
 State the function of veins.
 Outline the roles of gravity and skeletal muscle
pressure in maintaining flow of blood through a
vein.
6.2.U6: Valves in veins and the heart ensure
circulation of blood by preventing backflow
(Oxford Biology Course Companion page 294).

Outline the structure and function of a pocket
valve.
6.2.S1: Identification of the blood vessels as
arteries, capillaries or veins from the structure of
their walls (Oxford Biology Course Companion page
294).


6
Circulatory
diseases
Compare the diameter, relative wall
thickness, lumen diameter, number of wall
layers, abundance of muscle and elastic fibres
and presence of valves in arteries, capillaries
and veins.
Given a micrograph, identify a blood vessel as
an artery, capillary or vein.
6.2.A2: Causes and consequences of occlusion of
the coronary arteries (Oxford Biology Course
Companion page 297).
 Describe the cause and consequence of
atherosclerosis.
 Outline the effect of a coronary occlusion on
heart function.
6.3.A1: Causes and consequences of blood clot
formation in coronary arteries (Oxford Biology
Course Companion page 304).
 State the function of the coronary arteries.
 Define coronary thrombosis.
 List sources of arterial damage that increase the
risk of coronary thrombosis.
 List factors that are correlated with an increased
risk of coronary thrombosis and heart attack.
D.1.A5: Cholesterol in blood as an indicator of
the risk of coronary heart disease (Oxford Biology
Course Companion page 669).
 Outline factors that indicate that dietary
cholesterol may not be the exclusive cause of the
correlation between blood plasma cholesterol
levels and risk of coronary heart disease.
D.4.A3: Causes and consequences of
hypertension and thrombosis (Oxford Biology
Course Companion page 690).
 Describe the relationship between



atherosclerosis and thrombosis.
Describe the relationship between
atherosclerosis and hypertension.
List consequences of hypertension.
Outline factors that are correlated with a
greater incidence of thrombosis and
hypertension.
D.1.U8: Overweight individuals are more likely to
suffer hypertension and type II diabetes (Oxford
Biology Course Companion page 664).
 Define hypertension.
 Outline the reasons for the relationship
between weight gain and hypertension.
D.4.S4: Analysis of epidemiological data relating
to the incidence of coronary heart disease
(Oxford Biology Course Companion page 692).
 Define epidemiology.
 List epidemiological factors that can predispose
ethnic groups to coronary heart disease.