Download Cardiovascular System

Cardiovascular System
R. Martinson
Revision June 2015
Heart Muscle
• Heart Muscle is unique from
all other muscles because it
can create and conduct
electrical impulses.
• The lining of the heart is the
ENDOCARDIUM
• The thick muscular middle is
called the MYOCARDIUM.
The myocardium must be
very strong to pump blood
to the extremities.
• The outer protective
covering is called the
PERICARDIUM
Blood flow through the heart
• Video on normal blood flow through the heart
courtesy of the Children’s Hospital of Philadelphia
• http://www.youtube.com/watch?v=JA0Wb3gc4mE
Blood flow
• In GENERAL…
• ARTERIES carry oxygenated blood AWAY from
the heart.
• VEINS carry de-oxygenated blood TOWARDS
the heart.
THE BIG EXCEPTION
• The big exception to this rule is PULMONARY
circulation. Wherein deoxygenated blood is
carried from the heart to lungs through
arterial blood flow and oxygenated blood is
sent back to the heart through veins.
Path of blood
• Blood LOW IN OXYGEN
(“deoxygenated”)
enters the RIGHT
ATRIUM through the
SUPERIOR (top) and
INFERIOR (bottom)
VENAE CAVAE, the
body's largest veins.
• The RIGHT ATRIUM
contracts, forcing blood
through the TRICUSPID
VALVE and into the
RIGHT VENTRICLE.
• The right ventricle
contracts, sending blood
through the PULMONARY
SEMILUNAR VALVE and
into the PULMONARY
TRUNK.
• The pulmonary trunk
divides into PULMONARY
ARTERIES, which take the
deoxygenated blood to
the capillaries of the
LUNGS.
• At the lungs, carbon
dioxide diffuses out of the
blood, and, oxygen
diffuses into it. The blood
is now OXYGENATED.
• The oxygenated blood
feeds into the
PULMONARY VEINS,
which take it from the
lungs to the LEFT
ATRIUM.
• .
• The left atrium
CONTRACTS, forcing
blood through the
bicuspid valve into the
LEFT VENTRICLE
• The left ventricle
CONTRACTS, forcing
blood through the
AORTIC SEMILUNAR
VALVE into the AORTA,
the body's largest
artery.
• The aorta divides into
smaller arteries, which
carry oxygenated blood
to all BODY TISSUES.
• IN REALITY, cardiac blood flow doesn't
happen in a linear sequence. Instead, the two
atria contract SIMULTANEOUSLY, and the two
ventricles also contract simultaneously.
Septum
• Because of the atrial
and ventricular septums
deoxygenated blood
NEVER MIXES with
oxygenated blood.
Electrical Conduction
• The heart is a muscular
organ made up of
Cardiac Muscle. Cardiac
Muscle is unique
because it generates
and conducts electrical
impulses.
• This special quality is
why hearts can be
shocked into sinus
rhythm with an AED
• Also, it’s the reason we
can diagnose certain
heart problems by using
an ECG machine.
Electrical conduction
• Electrical impulses
starting in the heart
cause the muscles to
contract and the heart
to beat.
• The right and left sides
of heart work together
in a cycle to produce a
heartbeat
Intercalated discs
• At the junction of each
cardiac muscle fiber is a
section called an
intercalated disc. This
disc serves to function
as a connection
between fibers and
allows contractions and
electrical impulses to
flow rapidly between
fibers.
Sinoatrial Node
– initiates impulses 70-80
times per minute
– establishes basic rhythm of
the heartbeat
– called the pacemaker of
the heart
– impulses move through
atria causing the two atria
to contract.
– at the same time, impulses
reach the second part of
the conduction system
Atrioventricular Node
– cells in the AV node
conduct impulses more
slowly, so there is a
delay as impulses travel
through the node
– this allows time for atria
to finish contraction
before ventricles begin
contracting
Atrioventricular bundle
“Bundle of His”
– From the AV node, impulses travel
through to the right and left
bundle branches
– These branches extend to the right
and left sides of the septum and
bottom of the heart.
– These branch to form the Purkinje
fibers that transmit the impulses to
the myocardium (muscle tissue)
– The bundle of His, bundle branches
and Purkinje fibers transmit quickly
and cause both ventricles to
contract at the same time
– After the ventricles complete their
contraction phase, they relax and
the SA node initiates another
impulse to start another cardiac
cycle.
Systemic Circulation
• Blood Vessels
• Outside of the heart, blood
is carried throughout the
body in blood vessels. The
body contains three basic
types of blood vessels.
• Arteries carry blood away
from the heart.
• Veins carry blood back to
the heart.
• Capillaries are microscopic
vessels that carry blood
between the arterial and
venous vessels.
Pulse Rate
• The number of beats per minute
• Varies with each individual depending on age,
sex and body size
– Adults: 60 – 90 bpm
– Adult men: 60 – 70 bpm
– Adult women: 65 – 80 bpm
– Children over 7: 70 – 90 bpm
– Children 1 to 7: 80 – 110 bpm
– Infants (less than 1): 100 – 160 bpm
Pulse Rate
• Bradycardia: pulse rates under 60 bpm
• Tachycardia: pulse rates over 100 bpm (except
in children)
• Any variations or extremes in pulse rates
should be reported immediately
Pulse Rhythm
• Should be noted along with rate
• Refers to the regularity of the pulse or the
spacing of the beats
• Described as regular or irregular
• Arrhythmia
– Irregular or abnormal rhythm
– Usually caused by a defect in the electrical
conduction pattern of the heart
Pulse Volume
• Should be noted along with rate and rhythm
• Describes the strength or intensity of the
pulse
• Described by words such as strong, weak,
thready or bounding
Basic Principles for Taking
Radial Pulse
• Position pt’s arm supported comfortably with
palm of hand turned down
• Use tips of 2 or 3 fingers to locate pulse site on
thumb side of wrist
• Count pulse for 1 full minute
• Note rate, rhythm and volume of pulse
• Record info as:
– 12/01/2014, 0830, P 82 strong and regular, Sally
Smith, NAC
The Cardiac Cycle
• Systole
– The period in which the
heart contracts, pushing
blood from the
ventricles into pulmonic
and systemic circulation
• Diastole
– The period in which the
heart relaxes, causing
the heart to again fill
with blood
Blood Pressure
• ‘Normal’ blood pressure
for adults is 120/80
• Systolic
• Diastolic
Systolic pressure is the
pressure against vessels as
the heart contracts, Diastolic
is the pressure against
vessels as the heart relaxes
Hypertension
• Hypertension is high blood pressure.
• This disease is often called the “silent killer” because it
may not show any symptoms. If left untreated, it can
lead to permanent damage to the heart, blood vessels,
and kidneys.
• Risk factors that contribute to this condition are family
history, race, obesity, smoking, stress, age, and a diet
high in saturated fat.
• There is no cure. Treatment involves medication to
control the blood pressure and to remove excess body
fluids, reducing stress, avoiding tobacco, improving
diet, and exercise.
Hypertension video
• http://www.youtube.com/watch?v=ATLXgeKG
9y0
Congestive Heart Failure (CHF)
• Congestive heart failure (CHF) occurs when the
heart is unable to pump enough blood to supply
the needs of the body. It may strike suddenly, or
it may progress over a period of time.
• Symptoms include swelling, shortness of breath,
fatigue, low blood pressure, and a rapid pulse.
• Treatment involves medication for the heart and
to remove excess body fluids, elastic support
hose, and oxygen therapy. In addition, rest and
lifestyle changes are needed to relieve symptoms.
Congestive Heart Failure
• http://www.youtube.com/watch?v=GnpLm9fz
YxU
Elastic Stockings
• https://www.youtube.com/watch?v=7MxWFJ
1_vdA