Anatomy and Physiology I

1. 1
Rob
Swatski
Associate
Professor
of
Biology
HACC
–
York
Campus
Chapter
20
Cardiovascular
System:
The
Heart
Textbookimages-Copyright©
2014JohnWiley&Sons,Inc.
Allrightsreserved.

2. 20_03a
2

3. 3

4. 4

5. 5

6. (a) Inferior view of transverse section of
thoracic cavity showing heart in mediastinum
Sternum
Muscle
Left lung
Esophagus
Sixth thoracic
vertebra
LEFT PLEURAL
CAVITY
Heart
PERICARDIAL
CAVITY
Right lung
Aorta
RIGHT
PLEURAL
CAVITY
POSTERIOR
ANTERIOR
View
Transverse plane
Pulmonary trunk
(artery)
Heart
LocaEon:
MediasEnum

7. Arch of aorta
Anterior
view
of
heart
in
thoracic
cavity
Pulmonary trunk
Left lung
LEFT SURFACE
APEX OF HEART
Superior vena
cava
RIGHT SURFACE
Right lung
Pleura (cut to
reveal lung inside)
Diaphragm
INFERIOR SURFACE
Heart

8. 8
Heart
OrientaEon
Apex:
anteriorly,
inferiorly,
le6-­‐side
Base:
posteriorly,
superiorly,
right-­‐side
Anterior
surface:
deep
to
sternum
&
ribs
Inferior
surface:
on
diaphragm
Right
border:
faces
right
lung
LeK
(Pulmonary)
border:
faces
le6
lung

9. 9
Heart
Surface
ProjecEon
Superior
right
point:
sup
border
-­‐
3rd
right
costal
carClage
Superior
leK
point:
inf
border
-­‐
2nd
le6
costal
carClage,
3
cm
le6
of
midline
Inferior
leK
point:
5th
intercostal
space,
9
cm
le6
of
midline
Inferior
right
point:
sup
border
-­‐
6th
right
costal
carClage,
3
cm
right
of
midline

10. 10
Pericardium
Fibrous
pericardium
(outer)
-­‐
dense
irregular
CT
-­‐
protects
&
anchors
heart
-­‐
prevents
overstretching
Serous
pericardium
(epicardium):
-­‐
thin,
delicate
membrane
-­‐
parietal
&
visceral
layers
-­‐
pericardial
cavity
-­‐
pericardial
fluid

11. PericardiEs
Cardiac
tamponade
11

12. 12
Layers
of
the
Heart
Wall
Epicardium:
2
layers
–
1)
visceral
layer
of
serous
pericardium
&
2)
adipose
Cssue
&
fibroelasCc
Cssue
Myocardium:
cardiac
muscle
Endocardium:
endothelium
&
CT
(lines
chambers
&
valves)

13. 13
Muscle
Bundles
of
the
Myocardium

14. 14
MyocardiEs
&
EndocardiEs
endocardiEs
myocardiEs

15. 15
Chambers
&
Sulci
of
the
Heart
4
Chambers:
-­‐
2
superior
atria
-­‐
2
inferior
ventricles
Sulci:
grooves
on
heart
surface
-­‐
contain
coronary
BVs
&
adipose
Coronary
sulcus
-­‐
encircles
heart
b/w
atria
&
ventricles
Anterior
interventricular
sulcus
-­‐
ant.
boundary
b/w
ventricles
Posterior
interventricular
sulcus
-­‐
post.
boundary
b/w
ventricles

16. 16

17. 17

18. 18

19. 19
Right
Atrium
Receives
blood
from
3
sources:
superior
vena
cava,
inferior
vena
cava,
&
coronary
sinus
Interatrial
septum
Fossa
ovalis:
remnant
of
fetal
foramen
ovale
Tricuspid
valve
-­‐
blood
flows
through
into
right
ventricle
-­‐
3
cusps
of
dense
CT
-­‐
“RAT
on
the
Right”
(Right
Atrioventricular,
Tricuspid)

20. 20
Right
Ventricle
Forms
most
of
ant.
surface
of
heart
Interventricular
septum
Trabeculae
carneae
Papillary
muscles
Chordae
tendineae
Pulmonary
semilunar
valve
-­‐
allows
blood
into
pulmonary
trunk

21. Papillary
Muscles
&
Chordae
Tendineae
21

22. 22

23. 23
LeK
Atrium
Forms
most
of
base
of
heart
Receives
blood
from
lungs
through
4
pulmonary
veins
-­‐
2
right
&
2
le6
Bicuspid
valve:
blood
flows
through
into
le6
ventricle
-­‐
2
cusps
-­‐
“LAMB
on
the
Le6”:
Le6
Atrioventricular,
Mitral,
or
Bicuspid

24. 24
LeK
Ventricle
Forms
apex
of
heart
Chordae
tendineae,
papillary
muscles,
&
trabeculae
carneae
AorEc
semilunar
valve
-­‐
allows
blood
into
ascending
aorta
-­‐
openings
to
the
coronary
arteries
directly
above
valve

25. 25
Myocardial
Thickness
&
FuncEon
Thickness
varies
based
on
each
chamber’s
funcCon:
-­‐
Atria
walls
are
thin;
Ventricle
walls
are
thick
-­‐
Right
ventricle
walls
are
thin;
LeK
ventricle
walls
are
thick

26. 26
Fibrous
Skeleton
of
Heart
Dense
CT
rings
surround
heart
valves
-­‐
fuse
together
&
merge
with
interventricular
septum
FuncEons
of
fibrous
skeleton:
-­‐
valve
support
structure
-­‐
Prevents
overstretching
of
the
valves
-­‐
inserCon
point
for
cardiac
muscle
bundles
-­‐
electrical
insulator
b/w
atria
&
ventricles

27. 27
AV
Valves
OPEN
Allow
blood
flow
from
atria
into
ventricles
when
ventricular
pressure
is
lower
than
atrial
pressure
Occurs
during
ventricular
relaxaEon:
-­‐
papillary
muscles
are
relaxed
-­‐
chordae
tendineae
are
slack

28. 28

29. 29
AV
Valves
CLOSED
Prevents
backflow
(regurgita/on)
of
blood
into
atria
Occurs
during
ventricular
contracEon:
-­‐
papillary
muscles
contract
-­‐
chordae
tendineae
pulled
taut
-­‐
valve
cusps
pushed
closed

30. 30
SL
valves
OPEN
during
ventricular
contracCon
-­‐
allow
blood
flow
into
pulmonary
trunk
&
aorta
SL
valves
CLOSE
during
ventricular
relaxaCon
-­‐
blood
fills
cusps
&
valves
close
-­‐
prevents
blood
from
flowing
backwards
into
ventricles
Semilunar
Valves

31. Superior view with atria removed: pulmonary
and aortic valves closed, bicuspid and
tricuspid valves open
PULMONARY
VALVE (closed)
Left coronary
artery
BICUSPID
VALVE (open)
TRICUSPID
VALVE (open)
AORTIC VALVE
(closed)
Right coronary
artery
POSTERIOR
ANTERIOR

32. 32

33. 33

34. 34
Heart
Valve
Disorders
Stenosis:
narrowing
of
valve
that
restricts
blood
flow
-­‐
Surgically
repaired
or
replaced
with
mechanical
valves
or
valves
from
human
donors
or
pigs
Insufficiency
or
incompetence:
valve
cannot
close
completely
Balloon
valvuloplasty

35. Mitral
Valve
Stenosis
35

36. 36
Systemic
CirculaEon
LEFT
side
of
heart
pumps
oxygenated
blood
to
body
LeK
atrium
à
LeK
ventricle
à
Aorta
à
Systemic
arteries
à
Arterioles
à
Systemic
capillaries
à
Organsà
Systemic
venules
à
Systemic
veins
à
Superior/Inferior
vena
cava/Coronary
sinus
à
Right
atrium

37. 37
Pulmonary
CirculaEon
RIGHT
side
of
heart
pumps
deoxygenated
blood
to
lungs
Right
atrium
à
Right
ventricle
à
Pulmonary
trunk
à
Pulmonary
arteries
à
Pulmonary
capillaries
à
Lungs
à
Pulmonary
Veins

38. 38

39. Oxygen-rich blood
Path
of
blood
flow
through
heart
Oxygen-poor blood
10. 8.
5.
7.
2.
1.
3.
5.
6.
10.
4.
Pulmonary
capillaries of
right lung
Key:
4.
Pulmonary
capillaries of
left lung
9. Systemic capillaries of
head and upper limbs
9. Systemic capillaries of
trunk and lower limbs

40. 40

41. 41
Coronary
CirculaEon
Blood
flow
into
the
myocardium
Supplies
the
cardiac
muscle
Cssue
of
the
heart
wall
Many
anastomoses

42. 42

43. 43
Coronary
Arteries
Right
coronary
artery
Marginal
branch
Posterior
interventricular
branch
LeK
coronary
artery
Anterior
interventricular
branch
or
Le6
anterior
descending
(LAD)
Circumflex
branch

44. 44

45. 45

46. 46
Coronary
Veins
Collect
wastes
from
myocardium
Great
cardiac
vein,
Middle
cardiac
vein,
Small
cardiac
vein,
Anterior
cardiac
vein
Drain
into
coronary
sinus

47. 47
Cardiac
Muscle
Tissue
Striated,
branching,
shorter
fibers
of
heart
Intercalated
discs
with
gap
juncEons
One
central
nucleus
per
fiber

48. 48
Cardiac
Muscle
Histology

49. 49
Cardiac
Muscle
Tissue
Same
acCn
&
myosin
arrangement
as
skeletal
muscle
Autorhythmic
Longer
contracCons
(longer
Ca+2
delivery)

50. 50
Cardiac
Myofibril

51. 51
ConducEon
System
Autorhythmic
fibers
à
spontaneous
APs
Propagate
APs
through
myocardium
Sinoatrial
(SA)
node
=
pacemaker

52. 52
SA
node
AV
node
AV
bundle
(of
His)
Right
&
leK
bundle
branches
Purkinje
fibers
ConducEon
System

53. 53

54. 54

55. 55
RegulaEon
of
the
ConducEon
System
Autonomic
Nervous
System
(ANS)
Hormones
(epinephrine)
Modify
heart
rate
&
strength
of
contracCon
They
do
NOT
establish
the
fundamental
rhythm

56. 56
AcEon
PotenEal
DepolarizaEon
Plateau
RepolarizaEon
Refractory
period

57. 57
Physiology
of
ContracEon

58. 58

59. 59
Electro-­‐
cardiogram
(ECG
or
EKG)
Visual
record
of
all
APs
during
each
cardiac
cycle
(heartbeat)
Detected
at
body’s
surface
DiagnosCc
value
Detects
abnormal
conducCon,
enlargement,
muscle
damage,
&
reasons
for
chest
pain

60. 60
ECG
P
wave
QRS
complex
T
wave

61. 61
DiagnosEc
Value
of
the
ECG
P-­‐Q
interval
S-­‐T
segment
Q-­‐T
interval

62. Ventricular diastole
(relaxation)
6
Repolarization of
ventricular contractile
fibers produces T
wave
5
Ventricular systole
(contraction)
4
Depolarization of
ventricular contractile fibers
produces QRS complex
3
Atrial systole
(contraction)
2
Depolarization of atrial
contractile fibers
produces P wave
1
Action potential
in SA node
P P P
P P P
R
Q
S
T

63. 63

64. 64

65. 65

66. 66

67. 67
Cardiac
Cycle
Systole
=
ContracCon
Diastole
=
RelaxaCon
At
75
beats/min,
1
cycle
=
0.8
sec
Pressure
&
volume
changes
during
cycle
Blood
pumped
from
high
to
low
pressure
areas

68. 68
Atrial
systole
(contrac'on)
Atrial
diastole
(relaxa'on)
Ventricular
systole
Ventricular
diastole
Cardiac
Cycle

69. 69
Blood
Volumes
End
Diastolic
Volume
(EDV)
=
130
ml
End
Systolic
Volume
(ESV)
=
60
ml
Stroke
Volume
(SV)
=
70
ml

70. 70
SV
=
EDV
-­‐
ESV

71. 71
Phases
of
the
Cardiac
Cycle
Isovolumetric
RelaxaEon
(all
valves
close)
Ventricular
Filling
(AV
valves
open)
Isovolumetric
ContracEon
(AV
valves
close)
Ventricular
EjecEon
(SL
valves
open)

72. 72

73. 73

74. 74
Ventricular
Pressures
AorCc
BP
=
120
mmHg
Pulmonary
trunk
BP
=
30
mmHg
Why?
How?

75. 75

76. 76
Heart
Sounds
AuscultaEon
Produced
when
valves
close
S1:
“lubb”
=
AV
valves
close
(louder,
longer)
S2:
“dupp”
=
SL
valves
close
(quiet,
shorter)

77. 77
Heart
Sounds

78. 78
Heart
Murmurs
Abnormal
sounds
before,
b/w,
or
a6er
normal
sounds
May
also
mask
normal
sounds
Caused
by
valve
disorders
(stenosis,
incompetency)

79. 79
Cardiac
Output
Volume
of
blood
ejected
each
minute
from
either
ventricle
CO
=
Stroke
Volume
(SV)
x
Heart
Rate
(HR)
70
ml
SV
x
75
beats/min
=
5.25
L/min
Cardiac
reserve

80. 80
RegulaEon
of
Stroke
Volume
Preload
ContracElity
AKerload

81. 81
Preload
The
greater
the
stretch,
the
greater
the
force
of
contracCon
The
greater
the
blood
volume,
the
greater
the
force
of
contracCon
Frank-­‐Starling
Law
of
the
Heart

82. 82
ContracElity
PosiEve
inotropic
agents
SCmulaCon
of
he
SympatheCc
division
of
the
Autonomic
Nervous
System
(ANS)
Hormones:
epinephrine
&
norepinephrine
Higher
intersCCal
Ca+2
Drugs
(digitalis)

83. 83
ContracElity
NegaEve
inotropic
agents
InhibiCon
of
the
SympatheCc
division
of
the
Autonomic
Nervous
System
(ANS)
Anoxia,
acidosis,
some
anestheCcs
Higher
intersCCal
K+
Drugs
(Calcium
channel
blockers)

84. 84
AKerload
The
back
pressure
in
the
arteries
that
the
ventricles
must
overcome…
…in
order
to
open
the
semilunar
valves
The
greater
the
BP
=
the
greater
the
a6erload

85. 85
CongesEve
Heart
Failure
If
a6erload
is
high,
more
blood
remains
in
the
ventricles…
…which
increases
the
preload
Le?
ventricular
failure
=
pulmonary
edema
Right
ventricular
failure
=
peripheral
edema

86. 86

87. 87
Neural
RegulaEon
of
Heart
Rate
Cardiovascular
center
in
medulla
oblongata
SympatheEc
impulses
increase
HR
&
force
of
contracCon
ParasympatheEc
impulses
decrease
HR

88. 88
Nervous
System
Receptors
Proprioceptors:
monitor
movements
Chemoreceptors:
monitor
blood
chemistry
Baroreceptors:
monitor
BP

89. Cardiovascular
(CV) center
Key:
Sensory (afferent) neurons
Motor (efferent) neurons
Medulla oblongata
Glossopharyngeal nerves
(cranial nerve IX)
Vagus nerves
(cranial nerve X,
parasympatheti
c)
SA node
Sympathetic trunk
ganglion
Cardiac accelerator
nerve (sympathetic)
Ventricular
myocardium
AV node
Baroreceptors
in arch of aorta
Baroreceptors
in carotid sinus
Spinal cord

90. 90

91. 91
Biochemical
RegulaEon
of
Heart
Rate
Oxygen
level:
hypoxia
pH:
acidosis
and
alkalosis
Hormones:
Epinephrine,
norepinephrine,
thyroid
hormones
CaEons:
Na+,
K+,
Ca+2
Other
factors:
Age,
gender,
physical
fitness,
body
temperature,
stress

92. 92

93. 93
High
blood
cholesterol
High
BP
Smoking
Obesity
Lack
of
regular
exercise
Family
history
Male
gender
Diabetes
Le6
ventricular
hypertrophy
Risk
Factors
for
Heart
Disease

94. 94
Plasma
Lipids
&
Heart
Disease
High
blood
cholesterol:
promotes
plaques
High-­‐Density
Lipoproteins
(HDLs)
Low-­‐Density
Lipoproteins
(LDLs)
Very
Low-­‐Density
Lipoproteins
(VLDLs)

95. 95
Coronary
Artery
Disease
(CAD)
Ischemia
Reduced
blood
flow
through
coronary
arteries
Causes
hypoxia
&
weakens
cardiac
muscle
Angina
Pectoris
Narrowing
of
coronary
arteries
Leads
to
reduced
blood
flow,
chest
pain,
pressure,
discomfort
Myocardial
InfarcEon
Complete
obstrucCon
of
coronary
blood
flow
causing
heart
amack

96. 96

97. 97
Coronary
Artery
Disease
ObstrucEons
Atherosclerosis
Coronary
artery
spasm
Coronary
artery
thrombosis

98. 98
Coronary
Artery
Bypass
GraKing
(CABG)

99. 99

100. 100

101. 101
Congenital
Heart
Defects

102. 102
Congenital
Heart
Defects,
cont.

103. 103
Arrhythmia
Irregularity
in
heart
rhythm
due
to
conducCon
system
defect
Bradycardia
Tachycardia
FibrillaEon

104. (d) Ventricular tachycardia
Ventricular fibrillation
(e) Ventricular fibrillation
Ventricular tachycardia