Principles of Anatomy
and Physiology
Thirteenth Edition
Gerard J. Tortora • Bryan H. Derrickson
Chapter 20
The Cardiovascular System: The Heart
Copyright © 2012 by John Wiley & Sons, Inc.
Transverse plane
ANTERIOR
Sternum
VIEW
Heart
Muscle
PERICARDIAL
CAVITY
Left lung
Esophagus
Right lung
Aorta
Sixth thoracic
vertebra
RIGHT PLEURAL
CAVITY
LEFT PLEURAL
CAVITY
POSTERIOR
(a) Inferior view of transverse section of thoracic
cavity showing heart in mediastinum
Superior vena cava
Arch of aorta
SUPERIOR BORDER
RIGHT BORDER
Pulmonary trunk
Right lung
Left lung
Pleura (cut to
reveal lung inside)
Heart
LEFT BORDER
Pericardium (cut)
APEX OF HEART
Diaphragm
INFERIOR SURFACE
(b) Anterior view of heart in thoracic cavity
Superior vena cava
Arch of aorta
Rib (cut)
Pulmonary trunk
Right lung
Left lung
Heart
Apex of heart
Diaphragm
(c) Anterior view
Pericardium
Epicardium
Myocardium
Endocardium
PERICARDIUM
Heart wall
ENDOCARDIUM
FIBROUS PERICARDIUM
PARIETAL LAYER OF
SEROUS PERICARDIUM
Coronary blood vessels
Trabeculae carneae
Pericardial cavity
MYOCARDIUM
(CARDIAC MUSCLE)
VISCERAL LAYER OF
SEROUS PERICARDIUM
(EPICARDIUM)
(a) Portion of pericardium and right ventricular heart wall showing
divisions of pericardium and layers of heart wall
Parietal layer
of serous
pericardium
Heart
Pericardial
cavity
Serous
pericardium
Pericardial
cavity
Visceral layer
of serous
pericardium
(c) Simplified relationship of serous pericardium to heart
Aorta
Superior vena cava
Pulmonary trunk
Superficial muscle
bundles in atria
Deep muscle bundle
in ventricle
Superficial muscle
bundles in ventricles
(d) Cardiac muscle bundles of myocardium
Left common carotid artery
Brachiocephalic trunk
Left subclavian artery
Arch of aorta
Superior vena cava
Ligamentum arteriosum
Ascending aorta
Left pulmonary artery
Right pulmonary artery
Pulmonary trunk
Fibrous pericardium (cut)
Left pulmonary veins
Right pulmonary veins
AURICLE OF LEFT ATRIUM
AURICLE OF RIGHT ATRIUM
Right coronary artery
RIGHT ATRIUM
CORONARY SULCUS
(deep to fat)
RIGHT VENTRICLE
Inferior vena cava
Branch of left coronary artery
LEFT VENTRICLE
ANTERIOR
INTERVENTRICULAR
SULCUS (deep to fat)
Descending aorta
(a) Anterior external view showing surface features
Brachiocephalic trunk
Left subclavian artery
Left common carotid artery
Arch of aorta
Superior vena cava
Ligamentum arteriosum
Ascending aorta
Left pulmonary artery
Left pulmonary veins
Right pulmonary veins
Pulmonary trunk
RIGHT AURICLE OF
RIGHT ATRIUM
LEFT AURICLE OF LEFT
ATRIUM
RIGHT ATRIUM
LEFT VENTRICLE
CORONARY SULCUS
ANTERIOR
INTERVENTRICULAR
SULCUS
RIGHT VENTRICLE
(b) Anterior external view
Left common carotid artery
Brachiocephalic trunk
Left subclavian artery
Arch of aorta
Descending aorta
Superior vena cava
Left pulmonary artery
Ascending aorta
Right pulmonary artery
Left pulmonary veins
Right pulmonary veins
LEFT ATRIUM
RIGHT ATRIUM
Coronary sinus
(in coronary sulcus)
Right coronary artery
LEFT VENTRICLE
Inferior vena cava
POSTERIOR
INTERVENTRICULAR SULCUS
(deep to fat)
Middle cardiac vein
(c) Posterior external view showing surface features
RIGHT VENTRICLE
Frontal
plane
Left common carotid artery
Left subclavian artery
Brachiocephalic trunk
Arch of aorta
Ligamentum arteriosum
Left pulmonary artery
Pulmonary trunk
Ascending aorta
Superior vena cava
Right pulmonary artery
PULMONARY VALVE
Opening of superior vena cava
Fossa ovalis
Left pulmonary veins
LEFT ATRIUM
AORTIC VALVE
BICUSPID (MITRAL) VALVE
RIGHT ATRIUM
CHORDAE TENDINEAE
Opening of coronary sinus
LEFT VENTRICLE
Opening of inferior vena cava
INTERVENTRICULAR SEPTUM
TRICUSPID VALVE
PAPILLARY MUSCLE
RIGHT VENTRICLE
TRABECULAE CARNEAE
Inferior vena cava
Descending aorta
Right pulmonary veins
(a) Anterior view of frontal section showing internal anatomy
Left subclavian artery
Brachiocephalic trunk
Left common carotid artery
Arch of aorta
Superior vena cava
Ligamentum arteriosum
Right pulmonary artery
Ascending aorta
Pulmonary trunk
RIGHT AURICLE
(cut open)
Left pulmonary vein
Pectinate muscles
LEFT AURICLE
RIGHT ATRIUM
Cusp of tricuspid valve
LEFT VENTRICLE
Chordae tendineae
INTERVENTRICULAR
SEPTUM
Papillary muscle
RIGHT VENTRICLE
TRABECULAE CARNEAE
(b) Anterior view of partially sectioned heart
Transverse
plane
ANTERIOR
Right ventricle
Left ventricle
Lumen
Lumen
View
Interventricular
septum
POSTERIOR
(c) Inferior view of transverse section showing differences in
thickness of ventricular walls
View
Transverse
plane
Pulmonary valve
PULMONARY FIBROUS RING
Left coronary artery
CONUS TENDON
Aortic valve
AORTIC FIBROUS RING
LEFT FIBROUS TRIGONE
Right coronary artery
RIGHT FIBROUS TRIGONE
Tricuspid valve
Bicuspid valve
RIGHT ATRIOVENTRICULAR
FIBROUS RING
LEFT ATRIOVENTRICULAR
FIBROUS RING
Superior view (the atria have been removed)
Left
atrium
BICUSPID VALVE CUSPS
Open
Closed
CHORDAE TENDINEAE
Left
ventricle
Slack
Taut
PAPILLARY MUSCLES
Relaxed
Contracted
(a) Bicuspid valve open
(b) Bicuspid valve closed
Cusp of
tricuspid
valve
Chordae
tendineae
Papillary
muscle
(c) Tricuspid valve open
ANTERIOR
Aortic valve
(closed)
Pulmonary valve
(closed)
Right coronary
artery
Left coronary
artery
Bicuspid valve
(open)
Tricuspid valve
(open)
POSTERIOR
(d) Superior view with atria removed: pulmonary and aortic valves
closed, bicuspid and tricuspid valves open
ANTERIOR
Pulmonary valve (open)
Aortic valve (open)
Bicuspid valve
(closed)
Tricuspid valve
(closed)
POSTERIOR
(e) Superior view with atria removed: pulmonary and aortic valves
open, bicuspid and tricuspid valves closed
ANTERIOR
Pulmonary trunk
Ascending aorta
PULMONARY
VALVE
Right coronary artery
Pectinate muscle
of left atrium
Pectinate muscle of
right atrium
Left coronary
artery
AORTIC VALVE
TRICUSPID VALVE
BICUSPID
(MITRAL)
VALVE
Coronary sinus
POSTERIOR
(f) Superior view of atrioventricular and semilunar valves
Semilunar cusp of
aortic valve
(g) Superior view of aortic valve
9. Systemic capillaries of head
and upper limbs
10.
4. Pulmonary
capillaries of
right lung
4. Pulmonary
capillaries of
left lung
8.
5.
3.
6.
5.
1.
Key:
7.
Oxygen-rich blood
2.
Oxygen-poor blood
10.
9. Systemic capillaries of trunk
and lower limbs
(a) Path of blood flow through heart
4. In pulmonary capillaries,
blood loses CO2 and gains O2
3.
Pulmonary trunk and
pulmonary arteries
5.
Pulmonary veins
(oxygenated blood)
6.
Left atrium
Pulmonary valve
2.
Right ventricle
Bicuspid valve
Tricuspid valve
1.
Right atrium
(deoxygenated blood)
7.
Left ventricle
Aortic valve
10.
Superior
vena
cava
Inferior
vena cava
Coronary
sinus
8.
Aorta and systemic
arteries
9. In systemic capillaries, blood
loses O2 and gains CO2
(b) Diagram of blood flow
Arch of aorta
Ascending aorta
LEFT CORONARY
Left auricle
Pulmonary trunk
CIRCUMFLEX BRANCH
RIGHT CORONARY
ANTERIOR
INTERVENTRICULAR
BRANCH
Right atrium
POSTERIOR
INTERVENTRICULAR
BRANCH
MARGINAL BRANCH
Left ventricle
Right ventricle
(a) Anterior view of coronary arteries
Superior vena cava
Pulmonary trunk
Left auricle
Right atrium
CORONARY SINUS
SMALL CARDIAC
GREAT CARDIAC
ANTERIOR CARDIAC
MIDDLE CARDIAC
Left
ventricle
Right ventricle
Inferior vena cava
(b) Anterior view of coronary veins
SUPERIOR
Arch of aorta
Ascending aorta
Left pulmonary artery
Right auricle
Pulmonary trunk
Left auricle
RIGHT CORONARY
ARTERY
GREAT CARDIAC VEIN
ANTERIOR CARDIAC
VEIN
LEFT CORONARY ARTERY
Right ventricle
CIRCUMFLEX BRANCH
MARGINAL BRANCH
LEFT MARGINAL BRANCH
Left ventricle
ANTERIOR INTERVENTRICULAR
BRANCH
INFERIOR
(c) Anterior view
TRIBUTARY TO GREAT
CARDIAC VEIN
Intercalated
discs
Opening of
transverse
tubule
Desmosomes
Gap junctions
Mitochondrion
Nucleus
Sarcolemma
Cardiac
muscle
fiber (cell)
(a) Cardiac muscle fibers
Sarcolemma
Transverse
tubule
Mitochondrion
Sarcoplasmic
reticulum
Thin filament
Nucleus
Thick filament
Z disc
M line
Z disc
H zone
I band
A band
I band
Sarcomere
(b) Arrangement of components in a cardiac muscle fiber
Frontal plane
Left atrium
Right atrium
1
SINOATRIAL (SA) NODE
2
ATRIOVENTRICULAR (AV)
NODE
3
ATRIOVENTRICULAR (AV)
BUNDLE (BUNDLE OF HIS)
4
Left ventricle
RIGHT AND LEFT BUNDLE
BRANCHES
Right ventricle
5
PURKINJE FIBERS
(a) Anterior view of frontal section
+ 10 mV
Action
potential
Membrane
potential
Threshold
– 60 mV
Pacemaker
potential
0
0.8
1.6
Time (sec)
(b) Pacemaker potentials and action potentials in
autorhythmic fibers of SA node
2.4
2
Plateau (maintained depolarization) due to
Ca2+ inflow when voltage-gated slow Ca2+
channels open and K+ outflow when some K+
channels open
3 Repolarization due to
Membrane
Potential (mV)
1
Rapid depolarization due to
Na+ inflow when voltagegated fast Na+ channels open
0.3 sec
Depolarization
Refractory period
Contraction
Repolarization
closure of Ca2+ channels and
K+ outflow when additional
voltage-gated K+ channels
open
R
Key:
Atrial contraction
Millivolts (mV)
Ventricular contraction
S–T
segment
T
P
P–Q
interval
Q
S
Q–T interval
Seconds
1
Depolarization of
atrial contractile
fibers produces P
wave
2
Atrial systole
(contraction)
3 Depolarization of ventricular
contractile fibers produces QRS
complex
R
P
P
P
Q
S
Action potential
in SA node
4
Ventricular systole
(contraction)
P
5 Repolarization of
6
ventricular contractile
fibers produces T wave
P
T
Ventricular diastole
(relaxation)
P
R
T
(a) ECG
P
1
8
Q
4
S
0.1 sec
0.3 sec
Atrial Ventricular
systole systole
0.4 sec
Relaxation
period
9 Aortic valve
closes
120
Dicrotic wave
100
(b) Pressure
(mmHg)
80
Left
ventricular
pressure
5
60
40
20
6 Aortic valve
opens
Bicuspid
valve
closes
10
Bicuspid
valve opens
Left atrial
pressure
2
0
(c) Heart sounds
S1
Aortic
pressure
S2
S3
S4
(c) Heart sounds
S1
130
3
S2 S3
S4
End-diastolic volume
Stroke
volume
(d) Volume in
ventricle (mL)
60
7 End-systolic volume
0
(e) Phases of the
cardiac cycle
Atrial
contraction
Isovolumetric
contraction
Ventricular
ejection
Isovolumetric
relaxation
Ventricular
filling
Atrial
contraction
1
2
3
Aortic valve
4
Tricuspid valve
Pulmonary valve
Bicuspid valve
5
6
Anterior view of heart valve locations and auscultation sites
INPUT TO CARDIOVASCULAR CENTER
From higher brain centers: cerebral
cortex, limbic system, and hypothalamus
From sensory receptors:
Proprioceptors—monitor movements
Chemoreceptors—monitor blood chemistry
Baroreceptors—monitor blood pressure
OUTPUT TO HEART
Cardiac accelerator
nerves (sympathetic)
Increased rate of spontaneous depolarization in SA
node (and AV node) increases heart rate
Increased contractility of atria and ventricles
increases stroke volume
Cardiovascular
(CV) center
Vagus nerves (cranial
nerve X, parasympathetic
Decreased rate of spontaneous depolarization in
SA node (and AV node) decreases heart rate
Increased end-diastolic volume
(stretches the heart)
Increased PRELOAD
Within limits, cardiac muscle fibers
contract more forcefully with stretching
(Frank–Starling law of the heart)
Positive inotropic agents such as
increased sympathetic stimulation;
catecholamines, glucagon, or thyroid
hormones in the blood; increased Ca2+
in extracellular fluid
Increased CONTRACTILITY
Positive inotropic agents increase
force of contraction at all
physiological levels of stretch
Decreased arterial blood pressure
during diastole
Decreased AFTERLOAD
Semilunar valves open sooner when
blood pressure in aorta and
pulmonary artery is lower
Increased STROKE VOLUME
Increased CARDIAC OUTPUT
Increased HEART RATE
Increased sympathetic stimulation
and decreased parasympathetic
stimulation
NERVOUS SYSTEM
Cardiovascular center in medulla
oblongata receives input from
cerebral cortex, limbic system,
proprioceptors, baroreceptors, and
chemoreceptors
Catecholamine or thyroid hormones
in the blood; moderate increase in
extracellular Ca2+
CHEMICALS
Infants and senior citizens, females,
low physical fitness, increased
body temperature
OTHER FACTORS
Recipient's heart
Aorta
Pulmonary artery
Superior vena cava
Left atrium
Partial left atrium
Right atrium
Inferior vena cava
Donor's heart
(a) Donor’s left atrium is sutured to recipient's left atrium
Recipient's superior vena cava
Donor's right atrium
Recipient's inferior vena cava
(b) Donor's right atrium is sutured to recipient's superior and inferior venae cavae
(c) Transplanted heart with sutures
Thoracic
aorta
Catheter
Anterior view
Posterior view
(a) Intra-aortic balloon pump
Aorta
Outflow
tube
Outflow
one-way valve
Inflow
tube
Left
ventricle
Implanted left ventricular
assist device (LVAD)
Inflow one-way valve
Pump unit
Parts of left ventricular
assist device (LVAD)
Driveline
(b) Left ventricular assist device (LVAD)
Head end
Arterial end of heart
Cardiogenic
area
Truncus arteriosus
Fusion of
endocardial tubes
into primitive
heart tube
Endocardial
tubes
Neural plate
Bulbus cordis
Primitive ventricle
Primitive atrium
19 days
(a) Location of
cardiogenic area
Sinus
venosus
Venous end of heart
20 days
(b) Formation of
endocardial tubes
21 days
(c) Formation of
primitive heart tube
Truncus
arteriosus
22 days
(d) Development of regions in
the primitive heart tube
Superior
vena cava
Bulbus cordis
Aorta
Pulmonary trunk
Atrium
Primitive
ventricle
Primitive
atrium
Ventricle
Sinus
venosus
23 days
Inferior
vena cava
24 days
(e) Bending of the primitive heart
28 days
(f) Orientation of atria and ventricles to
their final adult position
Superior vena cava
Pulmonary veins
Future interatrial
septum
Atrium
Atrioventricular canals
Ventricle
Endocardial cushion
Future interventricular
septum
Inferior vena cava
About 28 days
Foramen ovale
Right atrium
Left atrium
Tricuspid valve
Bicuspid valve
Right ventricle
Left ventricle
About 8 weeks
Atherosclerotic
plaque
LM
(a) Normal artery
16x
LM
(b) Obstructed artery
Partially obstructed
space through
20x which blood flows
Ascending
aorta
Grafted
vessel
Obstruction
(a) Coronary artery bypass grafting (CABG)
Balloon
Narrowed lumen
Atherosclerotic of artery
Coronary
plaque
artery
Balloon catheter with uninflated balloon is
threaded to obstructed area in artery
When balloon is inflated, it stretches arterial
wall and squashes atherosclerotic plaque
After lumen is widened, balloon is deflated and
catheter is withdrawn
(b) Percutaneous transluminal coronary angioplasty (PTCA)
Stent
Lumen
of artery
(c) Stent in an artery
(d) Angiogram showing a stent in the circumflex artery
Narrow segment
of aorta
Ductus arteriosus
remains open
Foramen ovale
fails to close
(a) Coarctation of the aorta
(b) Patent ductus arteriosus
(c) Atrial septal defect
Stenosed
pulmonary
valve
Aorta emerges
from both
ventricles
Interventricular
septal defect
Opening in
interventricular
septum
Enlarged
(hypertrophied)
right ventricle
(d) Ventricular septal defect
(e) Tetralogy of Fallot
R–R interval
P–R
interval
(a) Normal electrocardiogram (ECG)
Long P–R
interval
(b) First-degree AV block
Irregular R–R intervals
No detectable P waves
(c) Atrial fibrillation
Ventricular tachycardia
Ventricular fibrillation
(d) Ventricular tachycardia
(e) Ventricular fibrillation