This document describes the layers of the heart and the cardiovascular system, including the circulatory, electrical conduction, and valvular components. It explains the cardiac cycle and how factors like preload and afterload impact stroke volume. Key anatomical structures are defined, such as the sinoatrial node, atrioventricular node, and bundle of His. Normal heart sounds, murmurs, and pulsations are characterized. Interactions between the cardiovascular system and other body systems are also outlined.

1. Assessing the cardiovascular
System
Dr/Magda Bayoumi

7. Layers of the Heart
 Endocardium: Inner layer of heart; a smooth,
thin layer of endothelium and connective
tissue. smooth inner lining of the heart.
 Myocardium:
 Middle and thickest layer of heart; heart
muscle.
 Responsible for cardiac contraction.
 Epicardium: The layer of serous pericardium
on heart’s surface. Contains main coronary
blood vessels.

8.  Pericardium: Sac that surrounds the heart and roots
of the great vessels.
 Composed of two layers: fibrous pericardium
(outer layer of fibrous connective tissue) and serous
pericardium.
 Serous pericardium also has two layers: outer or
parietal layer
 That lines the fibrous layer and visceral or inner layer
that lines the heart and is also called the
 Epicardium.
 Serous pericardium contains pericardial fluid
 (10–20 mL of serous fluid).
 Pericardial fluid moistens the pericardial sac
between the two layers and prevents friction
during systole and diastole.

9. The Circulatory System
 The circulatory system has two main
networks, the pulmonary circulation and
the systemic circulation.
 coronary circulation is part of the systemic
circulation and supplies the heart itself.
 The pulmonary circulation involves blood
vessels that circulate blood through the
pulmonary arteries, the lungs, and the
pulmonary veins.

10.  Unoxygenated blood enters the pulmonary
circulation from the right and left pulmonary
arteries.
 The unoxygenated blood then flows through
the pulmonary arterioles to the lung capillaries,
where the exchange of carbon dioxide and
oxygen occurs.
 The oxygenated blood then enters the
pulmonary venules that lead to the pulmonary
veins.
 Oxygenated blood is then carried back to the
left atrium through the right and left pulmonary
veins.

11. Systemic Circulation
 The systemic circulation is responsible for
supplying oxygen to every cell in the body
through the arterial system and then
returning unoxygenated blood to the heart
through the venous system.
 Oxygenated blood flows into the left atrium
from the pulmonary circulation.
 The left atrium then pumps the oxygenated
blood into the left ventricle, which in turn
expels the oxygenated

12. Coronary Circulation
 The coronary circulation consists of the
right and left coronary arteries and the
coronary sinus and cardiac veins. The
coronary arteries are the first branches
off the aorta.
 The cardiac veins drain into the coronary
sinus, which in turn drains directly into
the right atrium.

15.  blood through the aorta into the arterial
systemic circulation. From the aorta, blood then
flows through smaller arterioles to the systemic
capillaries. The systemic capillaries link the
arterial and venous systems.
 At this point, exchange of oxygen, nutrients,
and wastes occurs. From the capillaries,
unoxygenated blood then flows through the
venules, into the larger veins, and then to the
superior and inferior vena cavae.
 Unoxygenated blood then enters the right
atrium and is pumped to the right ventricle into
the pulmonary circulation to continue the cycle.

17. Mechanisms of Heart Sounds
 Heart sounds are the result of events
within the heart. The movement and
pressure of the blood
(hemodynamics), the activity of the
electrical conduction system, and the
movement of the valves affect the
sounds that you hear

18. The Cardiac Cycle
 The cardiac cycle comprises systolic and
diastolic phases. The systolic phase is
the contraction or emptying
phase, and the diastolic phase is the
resting or filling phase.
 The atria and ventricles alternate through
the systolic and Diastolic phases; while
the atria are contracting, the ventricles
are relaxing, and vice versa.

19. Ventricular Diastole
 Ventricular diastole marks the beginning
of the filling phase. Very shortly after the
onset of ventricular diastole, the pressure
in the ventricles is less than that of the
atria, and the mitral and tricuspid
valves open to allow filling of the
ventricles (the rapid-filling phase of
diastole).

20. Ventricular Systole
 With ventricular contraction, the pressure
in the ventricles will exceed that in the
atria.
 This results in closure of the mitral and
tricuspid valves and marks the
beginning of ventricular systole.
 While the ventricles are contracting and
blood is being propelled from them, the
atria are relaxed (atrial diastole) and are
filling.

22.  The amount of blood ejected from the
heartwith each contraction is referred to
as the stroke volume.
 The cardiac output is the amount of
blood ejected per minute.
 Cardiac output equals stroke volume
multiplied by heart rate.

23. The Stroke Volume
 Preload refers to the volume of blood in the
ventricles at t he end of diastole.
 An increase in venous return to the heart
will, in turn, increase preload. Factors that
affect venous return include:
 Venous blood reservoirs
 Skeletal muscle pump:
 Venous tone:
 Respiratory pump:

26. After load is simply the work that the
heart has to do to push blood into the
aorta and around the body.

28.  Afterload reflects the end-systolic volume. It is
affected by the amount of resistance the
ventricles have to contract against. An increase
in after-load results in a decrease in stroke
volume. After-load may be affected by:
 ■ Arterial elasticity.
 ■ Peripheral vascular resistance.
 ■ Aortic valve resistance.
 ■ Viscosity and volume of blood.
 ■ Contractility,which reflects the force of
contraction.
 ■ Positive inotropes,which increase the force
of contraction.
 ■ Negative inotropes, which decrease the
force of contraction.

29. The Heart’s Electrical Conduction
System
 The specialized cells of the conduction
system have
automaticity,excitability, conductivity and
refractoriness.
 Automaticity is the cell’s ability to initiate an
impulse.
 Excitability is the cell’s ability to respond to
an impulse and create an action potential.
Conductivity is the cell’s ability to transmit
an impulse.
 Refractoriness is the cell’s ability to respond
to the transmitted impulse.

30.  The sinoatrial (SA) node is the normal
pacemaker of the heart located in the right
atrium near the superior vena cava
entrance point.
 The SA node paces the normal adult heart
at 60 to 100 BPM.
 The activation of the SA node passes
through the atria and results in atrial

32.  electrical activity is then conducted to the
atrioventricular (AV) node.This node is located at
the base of the right atrium between the atria and the
ventricles. It has the ability to pace the heart at a rate
of 40 to 60 BPM.
 The electrical impulse is then transmitted.
 from the AV node to the bundle of His, which divides
into two branches, the right and the left, which
traverse the interventricular septum.
 Finally, the impulse is transmitted to small branches
that eventuate into the Purkinje fibers, which
stimulate the ventricles to contract.
 The pacer ability of the bundle of His is 20 to 40 BPM.

33. The Valves
 S1, the first heart sound, results from
the closure of the mitral (M1) and
tricuspid (T1) valves. M1 and T1
normally close within approximately 0.02
second or less. These valve sounds are
often heard as a single sound. S1 is best
heard at the apex or left lateral sternal
border (LLSB) with the diaphragm of the
stethoscope.

34. The Second Heart Sound (S2)
 When the systolic pressure in the
ventricles decreases below that of the
aorta and the pulmonary artery (toward
the end of systole), the aortic (A2) and
pulmonic (P2) valves close, producing
the second heart sound.
 Clinically, this sound marks the end of
systole and the beginning of diastole.
 A2 and P2 normally close about 0.02
second from each other; consequently,
they may occasionally be heard as a
single sound.

35. Extra Heart Sounds
 Additional sounds that may be heard
during auscultation , include early
ejection click, mid systolic ejection click,
opening snap, S3, and S4.These sounds
do not always indicate pathology.

36. Interaction With Other Body Systems
ENDOCRINE
 Distributes hormones throughout body via
circulatory system.
 Cardiac muscle cells secrete atrial natriuretic
peptide (ANP), which helps maintain fluid and
electrolyte balance and lowers volume and
blood pressure. Erythropoietin regulates RBC
production. Epinephrine and norepinephrine
increase heart rate and force of contraction.
URINARY
 Helps regulate volume within vascular system.
Renin/angiotensin system affects B/P.
 Erythropoietin affects RBC production.

37. LYMPHATIC
 Delivers WBCs and antibodies to fight
pathogens.
 And heart from pathogens Protects vascular
system.
REPRODUCTIVE
 Distributes reproductive hormones. Delivers
nutrients to reproductive organs.
 Vascular system needed for changes that
occur during sexual arousal.
 Premenopausal women have lower
incidence of heart disease.

38. RESPIRATORY
 RBCs exchange oxygen and carbon
dioxide in lungs and transport it to
peripheral system. Provides oxygen to
and removes wastes from
cardiovascular system. Lungs convert
angiotensin I to II, which helps maintain
blood pressure.

39.  INTEGUMENTARY
 Responds to skin injury or infection by
delivering clotting factors and immune
system response to affected area.
 Stimulation of mast cells in response to
injury or infection.
 Produces local changes in blood
pressure and release of ADH, which
helps blood flow and capillary
permeability.

40. SKELETAL
 Delivers calcium and minerals to bones for bone
growth. Delivers parathormone and calcitonin.
 Provides calcium for normal heart muscle
contraction.
 Produces blood cells in bone marrow.
 Skeletal framework protects heart.
MUSCULAR
 Delivers nutrients to muscles and throughout
circulatory system.
 Removes carbon dioxide, lactic acid and heat
produced by muscle activity.
 Muscles provide protection for neck vessels.
Heart is muscle responsible for pumping blood.
 Muscle contraction of legs helps with venous
return.

41. NEUROLOGICAL
 Endothelial cells of brain capillaries form a
semi-permeable membrane that maintains
blood-brain barrier.
 Controls peripheral circulation and heart
rate and increases blood volume and
pressure.
DIGESTIVE
 Delivers nutrients and hormones from site
of absorption and transports nutrients and
toxins to liver. Supplies cardiovascular
system with nutrients and absorbs water
and ions that help maintain blood volume.

42. Korotkoff’s Sounds:
 When you take your patient’s BP, you may hear five
distinct phases called Korotkoff’s sounds.These
phases occur because the BP cuff partially obstructs
blood flow and disturbs the laminar flow pattern,
causing turbulence. Korotkoff phases include the
following:
■ Phase I: A faint, clear, rhythmic tapping noise that
gradually increases in intensity. Intraluminal pressure
and cuff pressure are equal.
■ Phase II: A swishing sound that is heard as the
vessel distends with blood.
■ Phase III: Sounds become more intense. Vessel is
open in systole but not in diastole.
■ Phase IV: Sounds begin to muffle, and pressure is
closest to diastolic arterial pressure.
■ Phase V: Sounds disappear because vessel remains
open.

48. Central Artery and Jugular
Veins
 The sternocleidomastoid and trapezius
muscles are helpful in locating these vessels.
 The carotid artery and the internal jugular run
parallel to each other along the
sternocleidomastoid muscle toward the
sternal notch.
 The external jugular crosses the internal
jugular and lies posterior to the
sternocleidomastoid muscle.

50. Physical Assessment

51. Is It a Jugular Wave or a Carotid Arterial
Wave?
■ Carotid pulsation is normally palpable;
jugular pulsation is not. Because jugular
pulsation is a low-pressure wave, applying
pressure can easily obliterate it.
■ Carotid pulsation is not affected by position;
jugular venous pulsation is.
■ Carotid pulsation is unaffected by
respirations; jugular venous pulsation is.
■ Carotid pulsation has one positive wave;
jugular venous pulsation has three positive
waves

53. These graphics represent the normal cardiac pulsations and heart sounds. The jugular venous
pulsation normally has 3 positive waves—the a, c, and v waves and 2 negative troughs—x and y
troughs. The "a" wave is approximately synchronous with the first heart sound and just precedes
the carotid upstroke. The "v" wave coincides approximately with the second heart sound. The
normal carotid artery pulsation has a single positive wave during systole, followed by the
dicrotic notch (about the time of the second heart sound). The apex impulse represents the normal
brief, palpable systolic impulse occurring at the time of the first heart sound. In young normal
individuals there may be a palpable early diastolic filling wave representing the rapid filling
phase of ventricular diastole and corresponding to the normal third heart sound. Auscultation at
the aortic area reveals a normal first heart sound (S1) and second heart sound (S2). S2 is normally
louder than S1 in this area. At the pulmonary area there is normal inspiratory (physiologic)
splitting of the second sound due to asynchronous aortic and pulmonic closure. The aortic
component of the second heart sound (A2) normally precedes the pulmonic component (P2). At
the tricuspid area there is normal splitting of the first heart sound due to asynchronous mitral and
tricuspid closure. The mitral component of the first sound (M1) normally precedes the tricuspid
component (T1). At this area, physiologic splitting of the second sound may also be appreciated.
At the mitral area, the first and second heart sounds are normal. The first sound is normally
louder than the second heart sound and only the aortic component of the second heart sound is
normally appreciated. Occasionally a third heart sound is normal, reflecting deceleration of blood
into the left ventricle during the rapid filling phase of early diastole. Children and young adults
often have normal or physiologic third heart sounds.