Transcript POWERPOINT® LECTURE SLIDE PRESENTATION by LYNN CIALDELLA, MA, MBA, The University of Texas at Austin Additional Text by J Padilla exclusively for.

POWERPOINT® LECTURE SLIDE PRESENTATION
by LYNN CIALDELLA, MA, MBA, The University of Texas at Austin
Additional Text by J Padilla exclusively for Physiology 31 at ECC
UNIT 3
14
PART A
Cardiovascular
Physiology
HUMAN PHYSIOLOGY
AN INTEGRATED APPROACH
DEE UNGLAUB SILVERTHORN
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
FOURTH EDITION
About this Chapter
 Anatomical Review of the heart
 Cardiac muscle and the heart
 Cardiac muscle cell contraction
 Cardiac muscle cell action potential
 Conduction system and EKG
 The heart as a pump
 Mechanical Events of cardiac cycle
 Cardiac Cycle
 Wigger’s diagram
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation of the heart
The heart is the size of
your fist and weighs
less than a pound. It
began beating 22 days
after conception and
continues to
rhythmically contract
until the times dies. It
is located in the
thoracic cavity
posterior to the ribs and
just superior to the
diaphragm. It is
position so the apex
points to the left and
anterior to the rest of
the heart. The base
faces posteriorly.
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Structure of the Heart
The heart is composed mostly of myocardium
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Figure 14-7e–f
Anatomy: The Heart
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Structure of the Heart
The heart valves ensure one-way flow
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Figure 14-7g
Heart Valves
PLAY Animation: Cardiovascular System: Anatomy Review: The Heart
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-9
Heart Valves
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Cardiac Muscle versus Skeletal Muscle
 Smaller and have single nucleus per fiber
 Have intercalated disks
 Desmosomes allow force to be transferred
 Gap Junctions provide electrical connection
 T-tubules are larger and branch
 Sarcoplasmic reticulum is smaller
 Mitochondria occupy one-third of cell volume
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Anatomy: Cardiac Muscle Tissue
1% of myocardial
cells are
designed to
spontaneously
generate an
action potential.
They can
contract without
outside signal=
autorhythmic.
Pacemaker cells
do not have
sarcomeres
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-10
Histology of Myocardium
 Involuntary muscle
 Striated, has sarcomeres
 Many mitochondria
 Uni- or binucleated
 Branched
 Intercalated Disc
 Rhythmic contractions
 Does not fatigue as
easily as skeletal
 Does not have individual
neuromuscular junctions
 Independent contractions
 Require
high
O2
Copyright © 2007
Pearson
Education, Inc., publishing as Benjamin Cummings
Excitation-contraction coupling and relaxation
in cardiac muscle
1 Action potential enters
from adjacent cell.
Ca2+
ECF
1
2 Voltage-gated Ca2+
channels open. Ca2+
enters cell.
ICF
Ryanodine
receptor-channel
3 Ca2+ induces Ca2+ release
through ryanodine
receptor-channels (RyR).
2
3
SR
Sarcoplasmic
reticulum
(SR)
Ca2+
T-tubule
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-11, steps 1–3
Excitation-contraction coupling and relaxation
in cardiac muscle
1 Action potential enters
from adjacent cell.
Ca2+
ECF
1
2 Voltage-gated Ca2+
channels open. Ca2+
enters cell.
ICF
Ryanodine
receptor-channel
3 Ca2+ induces Ca2+ release
through ryanodine
receptor-channels (RyR).
2
3
SR
Sarcoplasmic
reticulum
(SR)
Ca2+
T-tubule
4
4 Local release causes
Ca2+ spark.
2+
5 Summed Ca Sparks
2+
create a Ca signal.
Ca2+
spark
5
Ca2+ signal
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-11, steps 1–5
Excitation-contraction coupling and relaxation
in cardiac muscle
1 Action potential enters
from adjacent cell.
Ca2+
ECF
1
2 Voltage-gated Ca2+
channels open. Ca2+
enters cell.
ICF
Ryanodine
receptor-channel
3 Ca2+ induces Ca2+ release
through ryanodine
receptor-channels (RyR).
2
3
SR
Sarcoplasmic
reticulum
(SR)
Ca2+
T-tubule
4
Ca2+
spark
5
4 Local release causes
Ca2+ spark.
2+
5 Summed Ca Sparks
2+
create a Ca signal.
2+
6 Ca ions bind to troponin
to initiate contraction.
Ca2+ signal
6
Contraction
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-11, steps 1–6
Excitation-contraction coupling and relaxation
in cardiac muscle
1 Action potential enters
from adjacent cell.
Ca2+
ECF
1
2 Voltage-gated Ca2+
channels open. Ca2+
enters cell.
ICF
Ryanodine
receptor-channel
3 Ca2+ induces Ca2+ release
through ryanodine
receptor-channels (RyR).
2
3
SR
Sarcoplasmic
reticulum
(SR)
Ca2+
T-tubule
Ca2+
stores
4 Local release causes
Ca2+ spark.
2+
5 Summed Ca Sparks
2+
create a Ca signal.
ATP
4
Ca2+
spark
8
Ca2+
2+
6 Ca ions bind to troponin
to initiate contraction.
5
7 Relaxation occurs when
Ca2+ unbinds from troponin.
Ca2+ signal
Ca2+
6
Contraction
7
Relaxation
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Actin
2+
8 Ca is pumped back
into the sarcoplasmic
reticulum for storage.
Myosin
Figure 14-11, steps 1–8
Excitation-contraction coupling and relaxation
in cardiac muscle
9
Ca2+
Ca2+
10
3
Na+
ECF
1
1 Action potential enters
from adjacent cell.
2 K+
ATP
ICF
Ryanodine
receptor-channel
2 Voltage-gated Ca2+
channels open. Ca2+
enters cell.
3 Na+
Ca2+
3 Ca2+ induces Ca2+ release
through ryanodine
receptor-channels (RyR).
2
3
SR
Sarcoplasmic
reticulum
(SR)
Ca2+
T-tubule
Ca2+
stores
4 Local release causes
Ca2+ spark.
2+
5 Summed Ca Sparks
2+
create a Ca signal.
ATP
4
Ca2+
spark
8
Ca2+
2+
6 Ca ions bind to troponin
to initiate contraction.
5
Ca2+
7 Relaxation occurs when
Ca2+ unbinds from troponin.
signal
Ca2+
6
7
Actin
2+
8 Ca is pumped back
into the sarcoplasmic
reticulum for storage.
9 Ca2+ is exchanged
with Na+.
Contraction
Relaxation
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Myosin
10 Na+ gradient is maintained
by the Na+-K+-ATPase.
Figure 14-11, steps 1–10
Myocardial Contractile Cells
Action potential of a cardiac contractile cell
+20
Na+ passes through
double gated voltage
channels
Plateau results from
decreased K+ and
increased Ca++
Plateau end when flux
is reversed
2
PK and PCa
0
Membrane potential (mV)
Resting membrane
potential is -90mv.
PX = Permeability to ion X
PNa
1
-20
-40
3
0
PNa
-60
-80
PK and PCa
4
4
-100
0
Phase
100
200
Time (msec)
300
Membrane channels
0
Na+ channels open
1
Na+ channels close
2
Ca2+ channels open; fast K+ channels close
3
Ca2+ channels close; slow K+ channels open
4
Resting potential
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Figure 14-13
Myocardial Contractile Cells
Refractory periods and summation in skeletal and
cardiac muscle- this prevents summation as it
happens in skeletal muscle
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-14c
Action Potentials in Cardiac Autorhythmic Cells
The membrane potential of pace maker cells is -60mv (pace
maker potential)but it drifts to threshold because of If
channels. Treshold is reached because If channels (allow
current to flow) are permeable to both K+ and Na+.
PLAY Animation: Cardiovascular System: Cardiac Action Potential
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-15
Modulation of Heart Rate
by the Nervous System
Sympathetic
stimulation
targets If
channels to
open rapidly.
Parasympathet
ic stimuation
targets K+ and
Ca++ channels,
it hyperpolarizes the
cell and slows
depolarization
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Figure 14-16
Action Potentials
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Electrical Conduction in Myocardial Cells
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Figure 14-17
Electrical Conduction in Heart
1
1
SA node
AV node
2
THE CONDUCTING SYSTEM
OF THE HEART
1 SA node depolarizes.
SA node
3
Internodal
pathways
2 Electrical activity goes
rapidly to AV node via
internodal pathways.
3 Depolarization spreads
more slowly across
atria. Conduction slows
through AV node.
AV node
A-V bundle
Bundle branches
4
Purkinje
fibers
4 Depolarization moves
rapidly through ventricular
conducting system to the
apex of the heart.
5 Depolarization wave
spreads upward from
the apex.
5
Purple shading in steps 2–5 represents depolarization.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-18
Electrical Conduction in Heart
1
1
SA node
AV node
THE CONDUCTING SYSTEM
OF THE HEART
1 SA node depolarizes.
SA node
Internodal
pathways
AV node
A-V bundle
Bundle branches
Purkinje
fibers
Purple shading in steps 2–5 represents depolarization.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-18, step 1
Electrical Conduction in Heart
1
1
SA node
AV node
2
THE CONDUCTING SYSTEM
OF THE HEART
1 SA node depolarizes.
2 Electrical activity goes
rapidly to AV node via
internodal pathways.
SA node
Internodal
pathways
AV node
A-V bundle
Bundle branches
Purkinje
fibers
Purple shading in steps 2–5 represents depolarization.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-18, steps 1–2
Electrical Conduction in Heart
1
1
SA node
AV node
2
THE CONDUCTING SYSTEM
OF THE HEART
1 SA node depolarizes.
SA node
3
Internodal
pathways
2 Electrical activity goes
rapidly to AV node via
internodal pathways.
3 Depolarization spreads
more slowly across
atria. Conduction slows
through AV node.
AV node
A-V bundle
Bundle branches
Purkinje
fibers
Purple shading in steps 2–5 represents depolarization.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-18, steps 1–3
Electrical Conduction in Heart
1
1
SA node
AV node
2
THE CONDUCTING SYSTEM
OF THE HEART
1 SA node depolarizes.
SA node
3
Internodal
pathways
2 Electrical activity goes
rapidly to AV node via
internodal pathways.
3 Depolarization spreads
more slowly across
atria. Conduction slows
through AV node.
AV node
A-V bundle
Bundle branches
4
Purkinje
fibers
4 Depolarization moves
rapidly through ventricular
conducting system to the
apex of the heart.
Purple shading in steps 2–5 represents depolarization.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-18, steps 1–4
Electrical Conduction in Heart
1
1
SA node
AV node
2
THE CONDUCTING SYSTEM
OF THE HEART
1 SA node depolarizes.
SA node
3
Internodal
pathways
2 Electrical activity goes
rapidly to AV node via
internodal pathways.
3 Depolarization spreads
more slowly across
atria. Conduction slows
through AV node.
AV node
A-V bundle
Bundle branches
4
Purkinje
fibers
4 Depolarization moves
rapidly through ventricular
conducting system to the
apex of the heart.
5 Depolarization wave
spreads upward from
the apex.
5
Purple shading in steps 2–5 represents depolarization.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-18, steps 1–5
Electrical Conduction
 AV node
 Direction of electrical signals
 Delay the transmission of action potentials
 SA node
 Set the pace of the heartbeat at 70 bpm
 AV node (50 bpm) and Purkinje fibers (25-40 bpm)
can act as pacemakers under some conditions
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Einthoven’s Triangle
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Figure 14-19
The Electrocardiogram
Three major waves: P wave, QRS complex, and T wave
Waves correspond to events of the cardiac cycle
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Figure 14-20
Electrical Activity
Correlation between an ECG and electrical events in the
heart
P wave: atrial
depolarization
START
P
The end
R
PQ or PR segment:
conduction through
AV node and A-V
bundle
T
P
P
QS
Atria contract.
T wave:
ventricular
Repolarization
Repolarization
R
T
P
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
QS
P Q wave
Q
ST segment
R
R wave
R
P
QS
P
R
Ventricles contract.
Q
P
S wave
QS
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-21
Electrical Activity
P wave: atrial
depolarization
START
P
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-21 (1 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
PQ or PR segment:
conduction through
AV node and A-V
bundle
P
Atria contract.
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-21 (2 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
PQ or PR segment:
conduction through
AV node and A-V
bundle
P
Atria contract.
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
P Q wave
Q
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Figure 14-21 (3 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
PQ or PR segment:
conduction through
AV node and A-V
bundle
P
Atria contract.
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
P Q wave
Q
R wave
R
P
Q
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Figure 14-21 (4 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
PQ or PR segment:
conduction through
AV node and A-V
bundle
P
Atria contract.
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
P Q wave
Q
R wave
R
P
R
Q
P
S wave
QS
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Figure 14-21 (5 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
PQ or PR segment:
conduction through
AV node and A-V
bundle
P
Atria contract.
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
P Q wave
Q
ST segment
R
R wave
R
P
QS
P
R
Ventricles contract.
Q
P
S wave
QS
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Figure 14-21 (6 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
PQ or PR segment:
conduction through
AV node and A-V
bundle
P
Atria contract.
T wave:
ventricular
Repolarization
Repolarization
R
T
P
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
QS
P Q wave
Q
ST segment
R
R wave
R
P
QS
P
R
Ventricles contract.
Q
P
S wave
QS
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-21 (7 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
The end
R
PQ or PR segment:
conduction through
AV node and A-V
bundle
T
P
P
QS
Atria contract.
T wave:
ventricular
Repolarization
Repolarization
R
T
P
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
QS
P Q wave
Q
ST segment
R
R wave
R
P
QS
P
R
Ventricles contract.
Q
P
S wave
QS
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-21 (8 of 9)
Electrical Activity
P wave: atrial
depolarization
START
P
The end
R
PQ or PR segment:
conduction through
AV node and A-V
bundle
T
P
P
QS
Atria contract.
T wave:
ventricular
Repolarization
Repolarization
R
T
P
ELECTRICAL
EVENTS
OF THE
CARDIAC CYCLE
QS
P Q wave
Q
ST segment
R
R wave
R
P
QS
P
R
Ventricles contract.
Q
P
S wave
QS
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-21 (9 of 9)
Electrical Activity
Comparison of an ECG and a myocardial action
potential
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Figure 14-22
Electrical Activity
Normal and abnormal electrocardiograms
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Figure 14-23
Mechanical Events
Mechanical events of the cardiac cycle
1
START
5
Late diastole: both sets of
chambers are relaxed and
ventricles fill passively.
Isovolumic ventricular
relaxation: as ventricles
relax, pressure in ventricles
falls, blood flows back into
cups of semilunar valves
and snaps them closed.
Ventricular ejection:
4 as ventricular pressure
rises and exceeds
pressure in the arteries,
the semilunar valves
open and blood is
ejected.
Atrial systole: atrial contraction
forces a small amount of
additional blood into ventricles.
2
3
Isovolumic ventricular
contraction: first phase of
ventricular contraction pushes
AV valves closed but does not
create enough pressure to open
semilunar valves.
PLAY Animation: Cardiovascular System: Cardiac Cycle
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-24
Mechanical Events
1
START
Late diastole: both sets of
chambers are relaxed and
ventricles fill passively.
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Figure 14-24, step 1
Mechanical Events
1
START
Late diastole: both sets of
chambers are relaxed and
ventricles fill passively.
2
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial systole: atrial contraction
forces a small amount of
additional blood into ventricles.
Figure 14-24, steps 1–2
Mechanical Events
1
START
Late diastole: both sets of
chambers are relaxed and
ventricles fill passively.
Atrial systole: atrial contraction
forces a small amount of
additional blood into ventricles.
2
3
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Isovolumic ventricular
contraction: first phase of
ventricular contraction pushes
AV valves closed but does not
create enough pressure to open
semilunar valves.
Figure 14-24, steps 1–3
Mechanical Events
1
START
Late diastole: both sets of
chambers are relaxed and
ventricles fill passively.
Atrial systole: atrial contraction
forces a small amount of
additional blood into ventricles.
2
Ventricular ejection:
4 as ventricular pressure
rises and exceeds
pressure in the arteries,
the semilunar valves
open and blood is
ejected.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
3
Isovolumic ventricular
contraction: first phase of
ventricular contraction pushes
AV valves closed but does not
create enough pressure to open
semilunar valves.
Figure 14-24, steps 1–4
Mechanical Events
1
START
5
Late diastole: both sets of
chambers are relaxed and
ventricles fill passively.
Isovolumic ventricular
relaxation: as ventricles
relax, pressure in ventricles
falls, blood flows back into
cups of semilunar valves
and snaps them closed.
Ventricular ejection:
4 as ventricular pressure
rises and exceeds
pressure in the arteries,
the semilunar valves
open and blood is
ejected.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial systole: atrial contraction
forces a small amount of
additional blood into ventricles.
2
3
Isovolumic ventricular
contraction: first phase of
ventricular contraction pushes
AV valves closed but does not
create enough pressure to open
semilunar valves.
Figure 14-24, steps 1–5
Cardiac Cycle
Left ventricular pressure-volume changes during one
cardiac cycle
KEY
EDV = End-diastolic volume
ESV = End-systolic volume
Stroke volume
Left ventricular pressure (mm Hg)
120
D
ESV
80
C
One
cardiac
cycle
40
EDV
B
A
0
65
100
Left ventricular volume (mL)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
135
Figure 14-25
Cardiac Cycle
At the beginning of the diastolic phase the
ventricles are relax and contain a very small
amount of blood
KEY
Left ventricular pressure (mm Hg)
EDV = End-diastolic volume
ESV = End-systolic volume
120
80
40
A
0
65
100
Left ventricular volume (mL)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
135
Figure 14-25 (1 of 4)
Cardiac Cycle
At then of the diastolic phase the volume as
increased because the ventricle has filled after
the ventricles contracted
KEY
Left ventricular pressure (mm Hg)
EDV = End-diastolic volume
ESV = End-systolic volume
120
80
40
EDV
B
A
0
65
100
Left ventricular volume (mL)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
135
Figure 14-25 (2 of 4)
Cardiac Cycle
At point C (systole phase) the pressure has
increased but the volume has not changed
KEY
EDV = End-diastolic volume
ESV = End-systolic volume
Left ventricular pressure (mm Hg)
120
80
C
40
EDV
B
A
0
65
100
Left ventricular volume (mL)
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135
Figure 14-25 (3 of 4)
Cardiac Cycle
At the end of systole the pressure is at is
highest and the volume has dropped.
Stroke volume= EDV - ESV
KEY
Left ventricular pressure (mm Hg)
EDV = End-diastolic volume
ESV = End-systolic volume
Stroke volume
120
D
ESV
80
C
One
cardiac
cycle
40
EDV
B
A
0
65
100
Left ventricular volume (mL)
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
135
Figure 14-25 (4 of 4)
Wiggers Diagram
This diagram
shows the
relationship
between the
cardiac cycle,
the ECG, the
heart sounds,
and pressure
changes in the
left ventricle
and aorta
0
Time (msec)
200 300 400
100
QRS
complex
Electrocardiogram
(ECG)
P
500
600
700
800
QRS
complex
Cardiac cycle
T
P
120
90
Dicrotic
notch
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
S1
Heart
sounds
S2
135
Left
ventricular
volume
(mL)
Atrial systole
65
Atrial Ventricular
systole
systole
Isovolumic
Ventricular
ventricular
systole
contraction
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Ventricular
diastole
Early
ventricular
diastole
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26
Wiggers Diagram
0
Electrocardiogram
(ECG)
P
100
Time (msec)
200 300 400
QRS
complex
Isovolumic
ventricular
contraction
Ventricular
systole
600
700
800
QRS
complex
Cardiac cycle
T
P
Atrial Ventricular
systole
systole
Atrial systole
500
Ventricular
diastole
Early
ventricular
diastole
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Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (1 of 13)
Wiggers Diagram
0
100
Time (msec)
200 300 400
500
600
700
800
135
Left
ventricular
volume
(mL)
Atrial systole
65
Isovolumic
ventricular
contraction
Atrial Ventricular
systole
systole
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
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Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (2 of 13)
Wiggers Diagram
0
100
Time (msec)
200 300 400
500
600
700
800
90
Pressure
(mm Hg)
60
30
Left atrial
pressure
Left
ventricular
volume
(mL)
135
65
Atrial Ventricular
systole
systole
Atrial systole
Isovolumic
ventricular
contraction
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (3 of 13)
Wiggers Diagram
0
Time (msec)
200 300 400
100
500
600
700
800
120
90
Pressure
(mm Hg)
60
Left
ventricular
pressure
30
S1
Heart
sounds
135
Atrial systole
Isovolumic
ventricular
contraction
S2
Atrial Ventricular
systole
systole
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (4 of 13)
Wiggers Diagram
0
100
Time (msec)
200 300 400
500
600
700
800
90
Pressure
(mm Hg)
60
30
Left
ventricular
volume
(mL)
135
Left
ventricular
pressure
S1
S2
65
Atrial Ventricular
systole
systole
Atrial systole
Isovolumic
ventricular
contraction
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (5 of 13)
Wiggers Diagram
0
Time (msec)
200 300 400
100
500
600
700
800
120
90
Pressure
(mm Hg)
60
Dicrotic
notch
Left
ventricular
pressure
30
Heart
sounds
S1
S2
Atrial Ventricular
systole
systole
Atrial systole
Isovolumic
ventricular
contraction
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (6 of 13)
Wiggers Diagram
0
Time (msec)
200 300 400
100
500
600
700
800
120
90
Dicrotic
notch
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
Heart
sounds
S1
S2
Atrial Ventricular
systole
systole
Atrial systole
Isovolumic
ventricular
contraction
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (7 of 13)
Wiggers Diagram
Time (msec)
0
Electrocardiogram
(ECG)
P
120
90
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
Heart
sounds
135
Left
ventricular
volume
(mL)
65
Atrial
systole
Atrial systole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-26 (8 of 13)
Wiggers Diagram
Time (msec)
0
Electrocardiogram
(ECG)
100
P
120
90
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
Heart
sounds
135
Left
ventricular
volume
(mL)
65
Atrial
systole
Isovolumic
ventricular
contraction
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-26 (9 of 13)
Wiggers Diagram
0
Time (msec)
200 300
100
QRS
complex
Electrocardiogram
(ECG)
P
T
120
90
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
S1
Heart
sounds
135
Left
ventricular
volume
(mL)
65
Atrial Ventricular
systole
systole
Ventricular
systole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-26 (10 of 13)
Wiggers Diagram
0
Time (msec)
200 300 400
100
QRS
complex
Electrocardiogram
(ECG)
P
T
120
90
Dicrotic
notch
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
S1
Heart
sounds
S2
135
Left
ventricular
volume
(mL)
65
Atrial Ventricular
systole
systole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-26 (11 of 13)
Wiggers Diagram
0
Time (msec)
200 300 400
100
QRS
complex
Electrocardiogram
(ECG)
P
500
600
700
800
Cardiac cycle
T
120
90
Dicrotic
notch
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
S1
Heart
sounds
S2
135
Left
ventricular
volume
(mL)
65
Atrial Ventricular
systole
systole
Ventricular
diastole
Late
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-26 (12 of 13)
Wiggers Diagram
0
Time (msec)
200 300 400
100
QRS
complex
Electrocardiogram
(ECG)
P
500
600
700
800
QRS
complex
Cardiac cycle
T
P
120
90
Dicrotic
notch
Pressure
(mm Hg)
Left
ventricular
pressure
60
Left atrial
30 pressure
S1
Heart
sounds
S2
135
Left
ventricular
volume
(mL)
Atrial systole
65
Isovolumic
ventricular
contraction
Atrial Ventricular
systole
systole
Ventricular
systole
Ventricular
diastole
Early
ventricular
diastole
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Atrial
systole
Late
ventricular
diastole
Atrial
systole
Figure 14-26 (13 of 13)
Stroke Volume and Cardiac Output
 Stroke volume
 Amount of blood pumped by one ventricle during a
contraction
 EDV – ESV = stroke volume
 Cardiac output
 Volume of blood pumped by one ventricle in a given
period of time
 CO = HR  SV (heart rate times stroke volume)
 Average = 5 L/min
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Reflex Control of Heart Rate
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-27
Stroke Volume
 Force of contraction
 Stroke volume
 Affected by length of muscle fiber and contractility of
heart
 Frank-Starling law
 Stroke volume increase as EDV increases
 EDV determined by venous return
 Skeletal muscle pump
 Respiratory pump
 Sympathetic innervation
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Stroke Volume
Length-force relationships in intact heart: a Starling
curve
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-28
Inotropic Effect
The effect of norepinepherine on contractility of the
heart
PLAY Animation: Cardiovascular System: Cardiac Output
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-29
Modulation of Cardiac Contractions
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-30
Factors that Affect Cardiac Output
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 14-31
Summary
 Cardiovascular—anatomy review
 Pressure, volume, flow, and resistance
 Pressure gradient, driving pressure, resistance,
viscosity, flow rate, and velocity of flow
 Cardiac muscle and the heart
 Myocardium, autorhythmic cells, intercalated disks,
pacemaker potential, and If channels
 The heart as a pump
 SA node, AV node, AV bundle, bundle branches, and
Purkinje fibers
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Summary
 The heart as a pump (continued)
 ECG, P wave, QRS complex, and T wave
 The cardiac cycle
 Systole, diastole, AV valves, first heart sound,
isovolumic ventricular contraction, semilunar valves,
second heart sound, and stroke volume
 Cardiac output
 Frank-Starling law, EDV, preload, contractility,
inotropic effect, afterload, and ejection fraction
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings