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SENIOR SCIENCE
BIONICS
Part 2: Circulatory System
1
Explain the relationship between the
structure and function of the following
parts of the heart
– valves
– atria
– ventricles
– major arteries and veins
Circulatory System
1
The blood enters the heart
from the body through the
vena cava. It enters the right
atrium travels through the
tricuspid valve and flows into
the right ventricle.
Circulatory System
2
The muscle surrounding the
right ventricle contracts,
pushing blood through the
pulmonic valve.
Circulatory System
3
Blood then travels to the
lungs through the pulmonary
artery.
Circulatory System
4
Here it exchanges carbon
dioxide for oxygen. The blood
then flows back to the heart
through the pulmonary vein
into the left atrium.
Circulatory System
5
Once the left atrium fills with
blood, the bicuspid valve
opens to allow blood into the
left ventricle.
Circulatory System
6
The left ventricle then
contracts, pushing blood
through the aortic valve into
the aorta.
Circulatory System
7
From here, oxygen rich
blood is circulated around
the body, giving oxygen and
nutrients to cells.
Arteries Vs Veins
•d
Arteries Vs Veins
a) Blood from the aorta travels to the body
T F
b) Blood moves into the left atrium through the tricuspid valve
T F
c) Blood travels through the pulmonic valve from the right ventricle
T F
d) The vena cava delivers blood to the heart from the lungs
T F
e) The left side of the heart contains oxygen rich blood
T F
f) The right side of the heart contains blood rich in carbon dioxide
T F
g) The pulmonary vein sends blood to the left ventricle
T F
h) The aortic valve opens, allowing blood from the left ventricle
into the aorta
i) The left ventricle is more muscular than the right ventricle.
T
F
T F
2
Explain that specialised tissues in the
heart produce an electrical signal that
stimulates rhythmic contractions of the
cardiac muscle
Electrical Activity of the Heart
• Sinoatrial (SA) node in the right atrium
send an electrical signal to the atria,
contracting the atria.
• This sends blood through the valves to
the ventricles on both sides of the heart.
• The electrical impulse from the atria
passes to an atrioventricular (AV)
junction to the ventricles.
• The AV junction can be likened to wires
between the atria and ventricles. The
impulse is slowed here, before being
passed to the ventricles. This allows the
atria to relax (and fill with blood) before
the ventricles contract.
Electrical Activity of the Heart
Electrical Activity of the Heart
Heart Beat
• The sound of a heartbeat is often described
as ‘lub–dub
• Lub = a long low–pitched sound, is produced
by the closing of the valves between the atria
and ventricles.
• Dub = a short, louder and high–pitched
sound, comes from the closing of the valves
between ventricles and the aorta and
pulmonary artery.
Electrocardiograph (ECG)
Electrocardiograph (ECG)
• Record these electrical impulses
• Metal electrodes are attached to the
skin on a person's arms, legs and
chest. The electrodes detect the
electrical activity and record it on
moving paper or electronically to
produce an electrocardiogram
(ECG).
• Doctors can use the patterns
produced to help diagnose heart
problems.
ECG
P Wave
produced by the
electrical signals that
cause the atria to
contract, forcing blood
into the ventricles.
QRS Wave
signals that bring about
the contraction of the
ventricles.
T Wave
recovery wave as the
electrical signals
spreads back over the
ventricles in the
opposite direction.
ECG
Identifying Aspects of a Heartbeat
Activity
• Spotlight Senior Science
• Pg 170
3
Discuss the problems that can result from
interruptions to the normal rhythm of the
heart
Interruptions to the heart’s normal rhythms
• Summarise each of the following from the Spotlight textbook (page 171)
•
•
•
•
Heart murmur
Ischaemia and fibrillation
Tachycardia and bradycardia
Damage to the pacemaker region of heart
4
Identify that a pacemaker will produce a
regular electrical impulse
5
Identify the types of materials used to make
pacemakers and the properties that make
these suitable for implanting in the body
Palpitations
• Palpitations occur when the heart beats too fast or too slow or beats in a
irregular manner. This happens when there is a malfunction in some part of
the heart's electrical system. These can be felt as:
rapid
heartbeat
Common Problems Requiring Medical Treatment
1
the heart beats too quickly
(more than 100 beats per minute)
2
the heart beats too slowly
(less than 50 beats per minute)
3
the heart beats irregularly
(disorganised electrical impulses)
Treatment
Artificial Pacemaker
Artificial Pacemaker
• Spotlight Senior Science
• Page 171-172
6
Describe the problems that can result
from faulty valves in the heart
Heart Valves
Heart Valves
Faulty Valves
Faulty valves can cause symptoms such as:
• chest pain
• shortness of breath
• inability to sleep
• fatigue and an inability to carry out daily activities
• swollen ankles
• abnormally large abdomen.
1
Stenosis
• Valve cannot open all the way because of disease or injury.
• Blood has a hard time flowing to the next heart chamber.
• Heart valves can become calcified (coated in layers of
calcium salts.)
• Narrow opening
of the valve.
2
Insufficiency or regurgitation
• Valve does not close
completely, and blood
leaks backwards.
• The heart has to work
harder to pump blood - it
has to push harder to get
blood through smaller
openings or it has to repump blood that has
leaked backwards.
2
Insufficiency or regurgitation
7
Describe the properties of materials such as
teflon/pyrolytic carbon that make them
versatile materials for making artificial body
parts, including heart valves
Artificial Valves
• Spotlight Senior Science
• Page 172-173
Artificial Valves
8
Describe and explain the effects of a build-up
of plaque on the walls of major arteries and
veins on blood flow to and from the heart
9
Discuss ways in which plaque could be
eliminated or altered to ease blood flow
Heart Health
• Spotlight Senior Science
• Page 173
Treatment for Coronary Heart Disease
• Spotlight Senior Science
• Page 173-174
THE END
• Spotlight Senior Science
• Answer To Think Questions
• Page 174