2. Is about 4.8 inches tall and 3.35 inches wide
Weighs about .68 lb. in men and .56 lb. in women
Beats about 100,000 times per day
Beats 2.5 billion time in an average 70 yr. lifetime
Pumps about 2000 gallons of blood each day
Circulates blood completely 1000 times each day
Pumps blood through 62,000 miles of vessels
Suffers 7.2 mil. CAD deaths worldwide each year
3. The heart resides in the pericardium
o A loose membranous sac.
Epicardium
◦ Continuous with the pericardium
Myocardium
◦ Composed of bands of involuntary striated
muscle fibers
Endocardium
◦ Thin layer of tissue lining the inside of the heart
4. Atria
◦ Thin-walled upper chambers
◦ Separated by atrial septum
◦ Right side of septum has oval depression, fossa
ovalis cordis, remnant of the foramen ovale
◦ Act as receiving chamber for blood returning from
the body and lungs
6. Ventricles
◦ Lower chambers which make up the bulk of the
muscle mass of the heart
◦ Left ventricle 2/3 larger than right ventricle
◦ Right ventricle is a thin-walled and oblong, like
pocket attached to left ventricle
7. Ventricles
◦ Contraction of left ventricle pulls in right
ventricle, aiding its contraction (termed left
ventricular aid)
◦ Separated by intraventricular septum
14. Pulmonary artery to left lung
Pulmonary Artery to right
lung
Pulmonary veins from left
lung
Pulmonary veins from
right lung
Superior vena cava
Aorta
Brachiocephalic artery
Left common carotid artery
Left subclavian artery
15. Arises from root of the aorta
Left Coronary Artery
Right Coronary Artery
Anterior Descending Artery
Circumflex Artery
Posterior Descending Artery
16. 1) Blood enters the heart through the inferior and superior vena
cava, flowing into the right atrium.
2) The blood passes through the tricuspid valve into the right
ventricle.
3) It then passes through the pulmonic semilunar valve, entering
the pulmonary artery of the pulmonary circulation.
4) It flows through the pulmonary bed of the right and left lungs to
the pulmonary vein, reentering the heart at the left atrium.
5) It then flows through the bicuspid valve into the left ventricle.
6) Passing through the aortic semilunar valve, the blood enters the
aorta and systemic vascular system.
17. Anterior descending artery
◦ Supplies anterior sulcus and apex
◦ “Widow maker” heart attack
Circumflex artery
◦ Supplies posterior side of left ventricle
18. Together supply most of left ventricle, left
atrium, 2/3 of intra ventricular septum, half
of intra atrial septum, and part of right atrium
22. Supplies anterior and posterior portions of
right ventricular myocardium, right atrium,
sinus node, posterior 1/3 of intraventricular
septum, and portion of base of right ventricle
23. Closely parallel the arterial system
Some coronary venous blood enters the
heart through the Thebesian veins
◦ Thebesian veins empty directly into all chambers
thus creating some venous admixture lowering
Pa02
24.
25. Large, highly elastic, low resistance to blood
flow
Small muscular arterioles of varying
resistance
26. Transport blood away from the heart
Generally contain oxygenated blood
Exception: pulmonary artery
Composed of three layers
◦ Tunica adventitia (external layer)
◦ Tunica media (thickest layer)
◦ Tunica intima (thinnest layer)
27. Tunica adventitia
◦ Consists of connective tissue surrounding
collagenous and elastic fibers
◦ Supports and protects the vessel
◦ Contains lymphatic vessels and nerve
fibers
◦ Has fine vessels that provide its blood
supply
28. Tunica media
◦ Thickest layer
◦ Composed of concentrically arranged
smooth muscle and elastic fibers
◦ Nerve fibers of tunica adventitia terminate
in tunica media
29. Tunica intima
◦ Thinnest layer of the artery
◦ Consists of the epithelium – flat layer of
simple squamous cells
◦ Common to all blood vessels including the
endocardium
30. Large arteries are termed conductance or elastic
arteries because the tunica media has less smooth
muscle and more elastic fibers
Medium sized arteries are termed the nutrient arteries
because they control the flow of blood to the various
regions of the body
Arterioles have a thin tunica intima and adventitia, but a
thick tunica media composed almost entirely of smooth
muscle and control blood flow to the capillary bed
◦ Called resistance vessels because they control the rate
that the blood leaves the arterial tree , control arterial
blood volume and thereby blood pressure
34. Microcirculation
Maintains constant environment for the cells and
tissues
Exchange of nutrients, gases, and wastes
The blood does not directly come in contact with
the parenchymal cells and tissues in the body,
but constituents of the blood first exit the micro
vascular exchange blood vessels to become
interstitial fluid, which comes into contact with
the parenchymal cells of the body. Lymph is
the fluid that is formed when interstitial fluid
enters the initial lymphatic vessels of the
lymphatic system
35. Pre-capillary sphincter valves
◦ Smooth muscle rings at the proximal end of the
capillary
◦ Contraction decreases blood flow
◦ Relaxation increases blood flow
◦ Responsive to local changes in PaO2, PaCO2, pH,
and temperature
◦ Called exchange vessels because they are the
site of gas, fluid, nutrient, and waste exchange
36.
37. Transport deoxygenated blood back to the heart – exception:
pulmonary vein
Composed of the same layers as arteries, but are thinner
Called capacitance or reservoir vessels because 70% to 75% of
the blood volume is contained in the venous system
Peripheral veins contain one-way valves.
◦ Valves are formed by duplication of endothelial lining
◦ Found in veins >2mm in diameter
◦ Are in areas subjected to muscular pressure, arms/legs
◦ Prevent retrograde flow of blood
38. Mechanisms aiding venous return to the
heart:
◦ Sympathetic venous tone
◦ Skeletal muscle pumping or “milking” combined
with the one-way valves
◦ Cardiac suction
◦ Thoracic pressure differences created by
respiratory efforts (thoracic pump)
39.
40.
41.
42. Consists of formed elements (cells)
suspended & carried in plasma (fluid part)
Total blood volume: 60-80 mL/kg of body
weight
Plasma is straw-colored liquid consisting of
90% H20 & dissolved solutes
◦ Includes ions, metabolites, hormones, antibodies,
proteins
43. Constitute 7-9% of plasma
Three types of plasma proteins: albumins,
globulins, & fibrinogen
◦ Albumin accounts for 60-80%
Creates colloid osmotic pressure that draws H20 from
interstitial fluid into capillaries to maintain blood
volume & pressure
Globulins carry lipids
◦ Gamma globulins are antibodies
Fibrinogen serves as clotting factor
◦ Converted to fibrin when clotting blood
◦ Serum is fluid left when blood clots
44. Composed of erythrocytes (RBCs) &
leukocytes (WBCs)
RBCs are flattened biconcave discs
◦ Generated in the red bone marrow by the
process of erythropoiesis from the
hemocytoblast, a common stem cell
◦ Shape provides increased surface area for
diffusion
◦ Lack nuclei & mitochondria
◦ Has semi-permeable membrane
◦ Contains hemoglobin molecule that
transports oxygen
◦ Approx. 30 trillion in the body
45. Is the formation of blood cells from stem
cells in marrow (myeloid tissue) & lymphoid
tissue
◦ RBC’s increase in number above normal with
chronic hypoxia
Erythropoiesis is formation of RBCs
◦ Stimulated by erythropoietin (EPO) from kidney
Leukopoiesis is formation of WBCs
◦ Stimulated by variety of cytokines
46. 2.5 million RBCs
created daily
Lifespan of 120 days
Old RBCs removed
from blood by
phagocytic cells in
liver, spleen, & bone
marrow
◦ Iron recycled back into
hemoglobin
production
47. Have nucleus, mitochondria, & amoeboid
ability
Formed in the myeloid tissue
Can squeeze through capillary walls
(diapedesis)
◦ Granular leukocytes help detoxify foreign
substances & release heparin
Include eosinophils, basophils, & neutrophils
49. Specialized type of blood cell
Fragments into small irregular pieces of
protoplasm called thrombocytes and platelets
Have no nucleus
Have a granular cytoplasm
Function in clot formation
50. Are smallest of formed
elements, lack nucleus
Constitute most of mass of
blood clots
Release serotonin to
vasoconstrict & reduce blood
flow to clot area
Secrete growth factors to
maintain integrity of blood
vessel wall
Survive 5-9 days
53. Systolic pressure
◦ Pressure during contraction phase of heart
◦ Normal value: 90 – 140 mmHg
Diastolic pressure
◦ Pressure during relaxation phase of heart
◦ Normal value: 60 – 90 mmHg
54. Mean arterial pressure (MAP)
◦ Average pressure in the arterial system over a
given time
◦ Normal value: 80 – 100 mmHg
55. Mean arterial pressure
MAP = (2 x diastolic pressure) + (systolic pressure)
3
A MAP of approximately 60 mmHg is necessary to
perfuse coronary arteries, brain, kidneys.
56. Reflects right atrial pressure
Influenced by changes in right ventricular
function
Measured with catheter placed in superior
vena cava just above right atrium
57. Purpose
◦ Assess blood volume status
◦ Administration of fluids
◦ Sampling of blood
◦ Measurement of SvO2
◦ Assessment of right ventricular pre-load
Normal value
o CVP: < 6 mmHg
o Right atrial pressure (RAP): 2-6 mmHg
58. Used to assess filling pressure of the left side
of heart
Measured by flow-directed, balloon-tipped
catheter
Measures
◦ Pulmonary artery pressures – systolic, diastolic,
mean
◦ Right ventricular preload (via right atrial pressure)
◦ Right ventricular afterload (via PA systolic pressure)
60. Total amount of blood pumped by the heart
per minute
Cardiac Output = Heart Rate x Stroke
Volume
Normal value – 5L/min
61. Cardiac Index
◦ Volume of blood pumped by the heart per
minute divided by body surface area
CI = CO
BSA
Normal range: 2.5 - 4.0 L/min per square meter
Low values can indicate cardiogenic shock
62. Amount of blood ejected from the ventricle
with each ventricular systole
End-systolic volume (ESV)
◦ Volume remaining after systole
63. End-diastolic volume (EDV)
◦ Volume to which the ventricles fill during
diastole
SV = EDV – ESV
Normal value: 60 – 130 ml/beat
64. Ejection fraction (EF)
◦ Proportion of EDV ejected on each stroke
EF = SV
EDV
◦ Normal value – 64%
65. Preload
◦ Initial stretch of the ventricle
◦ The greater the preload, the greater the tension
on contraction
66. Afterload
◦ Force against which the heart must pump.
◦ In clinical practice, left ventricular afterload
equals systemic vascular resistance.
67. Contractility
◦ Amount of systolic force exerted by heart muscle at any
given preload.
◦ Increases in contractility leads to higher EF, lower end
systolic volume, and higher stroke volume
◦ Decreases in contractility lead to lower ejection fraction,
higher end systolic volume, and decreased stroke volume.
68. Contractility
Inotropism: any factor which affects the
contractility of the heart
◦ Positive inotropism
Higher stroke volumes for a given preload:
indicating an increase in contractility
◦ Negative inotropism
Decreased stroke volumes for a given preload;
indicates a decrease in contractility
69. Heart rate
Autonomic nervous system
o Sympathetic: fight or flight: HR, RR, BP, pupil
dilation and bronchodilation
o Parasympathetic: rest and digest
70. Heart Rate
◦ Cardiac output directly proportional to heart
rate
Relationship exists up to 160 to 180
beats/min
Filling time for ventricles insufficient at
higher rates
71. Sum of all frictional forces opposing blood flow
through the vascular circulation.
SVR = Mean Aortic Pressure-Right Atrial Pressure
Cardiac Output
◦ Mean Aortic Pressure - use systolic pressure (normal mean = 90mmhg)
◦ Right Atrial Pressure - use central venous pressure (normal mean =
4mmhg)
◦ Cardiac Output normal mean = 5L/min.
Normal value: 15 – 20 mmHg/L/min
72. Cardiac anatomy
◦ Layers of the heart
◦ Chambers of the heart
◦ Valves
◦ Coronary arteries
Blood flow through the heart
Arterial system
◦ Structure of artery
◦ Purpose
◦ Major arteries
73. Venous system
◦ Structure of system
◦ Purpose
◦ Aids to venous flow
Capillary system
◦ Structure of system
◦ Purpose
74. Composition of blood
Plasma proteins
Types of cells, functions, normal values,
abnormalities
◦ Erythrocytes
◦ Leukocytes
◦ Megakaryocytes
◦ Platelets
◦ Hemoglobin
◦ Hematocrit
75. Definition, normal values, and formula (if
applicable)
◦ Systemic vascular resistance
◦ Systolic pressure
◦ Diastolic pressure
◦ Mean arterial pressure
◦ Cardiac output and index
◦ Stroke volume, esv, edv, ef
Factors affecting stroke volume
