The Circulatory
and
Cardiovascular Systems
Vocabulary
Important info
Headings
Surface Projection of the Heart
• Superior right point at the superior border of the
3rd right costal cartilage
• Superior left point at the inferior border of the
2nd left costal cartilage 3cm to the left of midline
• Inferior left point at the 5th intercostal space, 9
cm from the midline
• Inferior right point at superior border of the 6th
right costal cartilage, 3 cm from the midline
The Heart: Internal Anatomy
• Four chambers
– Atria
• Receiving chambers
– Right atrium
– Left atrium
– Ventricles
• Discharging chambers
– Right ventricle
– Left ventricle
• Heart valves
– Allow blood to flow in one direction ONLY
• Four valves
– Atrioventricular Valves – between atria and ventricles
• Bicuspid valve (left)
• Tricuspid valve (right)
– Semilunar valves between ventricle and artery
• Pulmonary semilunar valve
• Aortic semilunar valve
Layers of Heart Wall
• Epicardium
– visceral layer of
serous
pericardium
• Myocardium
– cardiac muscle
layer is the bulk
of the heart
• Endocardium
– chamber lining &
valves
Cardiac Myofibril
Valve Function
•Ventricles contract,
•Atria contract, blood blood pumped into
fills ventricles through aorta and pulmonary
A-V valves
trunk through SL
valves
Heart Murmur
• Heart murmurs are most
often caused by defective
heart valves.
• A valve may be unable to
close completely.
• This leads to regurgitation,
which is blood leaking
backward through the valve
when it should be closed
Normal heartbeat
murmur
Heart Sounds
Where to listen on chest wall for heart sounds.
What Causes the Heartbeat?
Conduction System of Heart
• Autorhythmic Cells
– Cells fire spontaneously, act as pacemaker and form conduction
system for the heart
• SA node
– cluster of cells in wall of Rt. Atria
– begins heart activity that spreads to both atria
– excitation spreads to AV node
• AV node
– in atrial septum,
transmits signal
to Bundle of His
• AV bundle of His
– the connection
between atria &
ventricles
– divides into
bundle branches
& purkinje fibers,
large diameter
fibers that
conduct signals
quickly
Rhythm of Conduction System
• SA node fires spontaneously
90-100 times per minute
• AV node fires at 40-50 times per minute
• If both nodes are
suppressed fibers
in ventricles by
themselves fire
only 20-40 times per
minute
• Artificial pacemaker
needed if pace is
too slow
• Extra beats forming at
other sites are called
Ectopic Pacemakers
– caffeine & nicotine
increase activity
Timing of Atrial & Ventricular Excitation
• SA node setting pace since is the fastest
• In 50 msec excitation spreads through both atria
and down to AV node
• 100 msec delay at
AV node due to
smaller diameter
fibers- allows atria
to fully contract
filling ventricles
before ventricles
contract
• In 50 msec
excitation spreads
through both ventricles simultaneously
Depolarization & Repolarization
• Depolarization
– Cardiac cell resting membrane potential is -90mv
– excitation spreads through gap junctions
– fast Na+ channels open for rapid depolarization
• Plateau phase
– 250 msec (only 1msec in
neuron)
– slow Ca+2 channels open, let Ca +2
enter from outside cell and from
storage in sarcoplasmic reticulum,
while K+ channels close
– Ca +2 binds to troponin to allow
for actin-myosin cross-bridge
formation & tension development
• Repolarization
– Ca+2 channels close and K+
channels open & -90mv is
restored as potassium leaves the cell
• Refractory period
– very long so heart can fill
Physiology of Contraction
• Depolarization, plateau, repolarization
Electrocardiogram---ECG or EKG
• EKG
– Action potentials of all active cells can be detected and recorded
• P wave
– atrial depolarization
• P to Q interval
– conduction time from
atrial to ventricular
excitation
• QRS complex
– ventricular
depolarization
• T wave
– ventricular repolarization
One Cardiac Cycle
• At 75 beats/min, one cycle requires 0.8 sec.
– Systole (contraction) and Diastole (relaxation) of both atria, plus the systole
and diastole of both ventricles
• End Diastolic Volume (EDV)
– volume in ventricle at end of diastole, about 130 ml
• End Systolic
Volume (ESV)
– volume in
ventricle
at end of
systole,
about 60 ml
• Stroke Volume
(SV)
– the volume
ejected per
beat from
each ventricle,
about 70 ml
– SV = EDV - ESV
Blood Pressure
• Measurements by health professionals are made on the pressure in large
arteries
– Systolic – pressure at the peak of ventricular contraction
(CONTRACTION OF HEART)
– Diastolic – pressure when ventricles relax (RELAXATION OF HEART)
• Pressure in blood vessels decreases as the distance away from the heart
increases
Pulse
• Pulse
– Pressure wave of
blood
• “Pressure Points”
– Area where pulse
is easily palpated
– Simple monitoring
Figure 11.16
Blood Pressure
Normal Systolic
Normal Diastolic
140-120 mm Hg
80-75 mm Hg
“120/80”
Variations in Blood Pressure
• Human normal range is variable
– Normal BP
• 140–110 mm hg systolic
• 80–75 mm hg diastolic
– Hypotension
• Low systolic
(below 110 mm hg)
• Often associated
with illness
– Hypertension
• High systolic
(above 140 mm hg)
• Can be dangerous if it is
chronic
Measuring Arterial Blood Pressure
Figure 11.18
Nervous System: Big Brother
• Nervous
system
controls
heartbeat
• Sympathetic NS
= fight or
flight
• Parasympathetic
NS =
relaxation
What is your Resting
Heart Rate?
Normal = 60-75 Beats/Minute
THE BLOOD
The 3 Main Functions of Blood:
1.
2.
3.
•
•
Transportation
Protection
Regulation
Blood is a connective
tissue in liquid form
Greatest benefit from
homeostasis:
–
Continuous flow of
blood thru 60,000 miles
of blood vessels
TRANSPORTATION:
• Blood moves thru body
where cells receive:
– Nutrients from digestive
organs
– Oxygen from lungs
– Hormones secreted from
endocrine gland
• Cells give blood waste
• (CO2, urea & uric
acid) & their
secretions
Protection:
• From harmful
microorganism &
their toxins
– Through Phagocytic
white blood cells
– Specialized proteins
called Antibodies
• Against fluid loss
after an injury by
clotting
Regulation:
• Regulates acid-base
balance of the body fluids
– By way of buffers
• Neutralize potential
harmful effects of:
– too much co2
– actic acid
– other compounds
Figure
This figure highlights some of the
major acute (short-term) effects
on the body during exercise.
• Body temp. by cooling or
heating parts of body
• Controlled by
Hypothalamus
• Controls volume of blood
flow to diff. areas of body
Properties of Blood:
• Color
• Volume
• pH
COLOR
• RED COLOR =
– HEMOGLOBIN (PIGMENT
PROTEIN)
• Arterial blood the O2 molecules
are chemically bound to
hemoglobin
– Crimson-red color
• Venous blood O2 mol. are not as
prevalent & blood=
– Dark red color w/a slightly bluish
tint
• SEEN THROUGH SKIN VEINS
LOOK GREENISH- BLUE but it
is NOT GREEN OR BLUE
VOLUME
• 8% OF BODY WEIGHT
– Most in vessels--rest
in heart
• Does not vary much
from day to day or year
to year
• Avg. Male =
– 5-6 liters of blood
• Avg. Female =
– 4-5 liters of blood
• Difference due to avg
body weight not sex
Apx. 8 pints
Figure
The shear rate dependence of
normal human blood viscoelasticity
at 2 Hz and 22 °C.
• Blood is thicker, denser,
& more adhesive than
H 2O
– Due to formed
elements (red blood
cells)
• Causes blood to flow
5x slower than H2O
• Resistance to flow =
viscosity
• Blood is
a viscous
substance b/c it resists
flow more than water
• Slightly alkaline (aka: basic)
• pH = 7.35-7.45
• Range stays small despite change in:
– Diet
– Cell secretions
– Metabolic rate
by buffering systems
that remove h+ ions
• If buffers fail:
– BLOOD TOO ACIDIC (pH below 6.0)
• Body cells stop functioning
• No homeostasis = Acidosis
• Too little acid in blood = Alkalosis (a lot less
common)
White Blood Cells-WBC
Leukocytes
• Less than 1% of
total blood volume
• 5000 TO 10,000
in cubic mm
• Any change in
number…
– High or low
indicates a
disease
Types:
• All contain a nucleus
– (unlike the RBC’s)
• Can wander outside the Circ.
System
• Wbc cells differ in:
– Nature of cytoplasm
– Size
– Shape of nucleus
• Response to different staining
techniques
• Divided into 2 groups by
cytoplasm differences:
– Granulocytes
– Agranulocytes
Granulocytes
• Cytoplasm contains
highly visible
pebble-like objects,
known as granules
• Twice the size of
RBC’s
• They contain a
nucleus that is split
into sections called
lobes
• Produced in red
marrow
• Three types:
– Eosinophils
– Neutrophils
– Basophils
• Names come from the type of stain that
brings out their distinguishing features
– Neutral
– Eosin
– Basic
Neutrophil:
• Most abundant =
granulocyte
• Stain pink in a
neutral stain
• Nucleus contains:
2 to 5 lobes
– Interconnected
by thin bridges
• Make up about 60%
of all wbc’s in a
normal blood sample
Eosinophils:
• 1 to 4% of WBC’s
in a normal blood
sample
• Granules stain
red in an acid
stain that
contains a dye
known as eosin
• Nucleus = 2 lobes
• Eosinophils are not:
– Very mobile
– Or active
– But can phagocytize
certain foreign
particles produced by
allergic reactions 
• Invading parasites
• Pollen grains
• Mold spores
Basophils:
• Rarest0.5%
or less of wbc’s
in blood
• Large granules
that stain blue
in basic stain
• Nucleus is often
bent into an
s-shape with
2 lobes
• Basophils & Mast
cells produce a
substance called
= histamine
– causes swelling
or inflammation
***Mast cells reside in tissues in the
body,
and basophils are in the blood stream.
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• Swelling tells
other wbc’s
where to find the
site of infection
Agranulocytes:
• Contain very small amount
of cytoplasmic granules
• 2 types of cells 
– Monocytes
– Lymphocytes
• Both produced in red bone
marrow
• Also produced by organs of
lymphatic system 
– Lymph nodes
– Spleen
– Thalamus
•
•
•
•
•
Monocyte:
Largest cells in blood
3x larger than rbc’s
2x larger than granulocytes
Nucleus can be round, oval, or lobed
Often occupies most
of the cell volume
• 3 to 8% of wbc’s in
a blood sample
Lymphocyte:
• Same size as the rbc =
the smallest wbc
• Nucleus is round and
large 
– Takes up almost all of
cell volume
• 25-33% of wbc’s in a
blood sample
Function:
• Protection from disease
• Move out of vessels =
diapedesis
• Once in the intestinal
fluid they act like
ameba, extending
streams of cytoplasmic
arms called =
pseudopodia
• To find infection they
sense chemicals
released by invading
microorganisms &
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e&n=21&ei=utf-8&js=1&fr=yfp-t-501-s&fr2=tabweb&tnr=20&vid=2317323
damages cells
• Once found the wbc
traps the microorganism
and engulfs it =
phagocytosis
• The primary cells used
for phagocytosis ar the
neutrophils & monocytes
• Neutrophils are mobile
& usually arrive 1st at
site of infection
• Monocytes are very
active too, large size
allows for phagocytizing
whole cells & large # of
bacteria
http://video.google.com/v
ideoplay?docid=5946616
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atch/697741/3134456
• When more wbc’s arrive at
the site of infection they
form a collection of
living—dead—broken cells
and plasma = pus
• Not only phagocytosis to
combat disease:
• Highly specific proteins
produced by the
lymphocytes =
– Antibodies 
• These act against
foreign particles and
toxins that enter
body
• Production of antibodies =
immunity
Platelets:
• Aka  Thrombocytes
• Formed elements that
are fragments of
complex cells
• During development in
red bone marrow, they
are formed when a
large precursor cell
breaks apart
• In small fragments
platelets are released
into blood stream for
circulation
• Larger fragments are broken down further
to form more platelets
• Each platelet contains:
– Cytoplasm surrounded by a plasma
membrane
– No nucleus but
most organelles
found in
cytoplasm
• 1/10 the size of
a RBC
• Shape = round or
oval disk
• 150,000 to 360,000
platelets per cubic mm
in normal blood sample
= less numerous than
rbc
• Prevention of fluid loss
• Initiate the formation
of blood clots
• This plugs up the
breaks in the blood
vessel wall after an
injury
Blood Groups
ABO & Rh
• Blood grouping is
based on reaction
b/t surface proteins
(on RBC plasma
proteins) & special
plasma proteins
• Agglutination = when
cells clump together
due to being
different blood
types
• Death occurs due to
destruction of RBC
• Antigen =
genetically
determined
proteins that
are located on
the surface
of the plasma
membrane of
a rbc
• Also called =
Agglutinogen
Antibody
• Antibody = protein within the plasma
• Also called = Agglutinins
• The rxn of an antigen & antibody determine if
blood will agglutinate or not
ABO System
• Only 2 antigens in
the ABO system
– A and B
• You can have one,
both or neither
antigens on your
rbc membrane
–
–
–
–
A (one)
B (one)
AB (both)
O (neither)
RBC
TYPE A
ANTIGEN A
TYPE B
ANTIGEN B
TYPE AB
ANTIGEN A
ANTIGEN B
NO ANTIGEN
TYPE O
PLASMA
ANTIBODY B
ANTI-B
ANTIBODY A
ANTI-A
NO ANTIBODY
ANTIBODY A
ANTIBODY B
ANTI-A / ANTI-B
BLOOD TYPE
CAN DONATE CAN RECEIVE
BLOOD TO
BLOOD FROM
A
A
AB
A
O
B
B
AB
B
O
AB
AB
O
A
AB
A
AB
B
O
B
O
O
Blood Transfusions
• If blood transfusion is
unsuccessful then rbc’s
die & hemoglobin &
bilirubin are released
into the body which can
cause kidney failure &
death!
• If you match the wrong
blood types agglutination
will occur
Figure: Illustration Of The Forward And Reverse Grouping
Reaction Patterns Of the ABO groups
Rh System
• Named after rhesus
monkey where it was 1st
discovered
• It was later found that
the Rh antigen is on the
RBC membrane of humans
• If you have the Rh antigen
you are:
– rh-positive.
• If you don’t have the rh
antigen you are:
– rh-negative.
SENSITIZATION
Rh-negative MOTHER PREGNANT FOR THE 1ST
TIME WITH Rh-positive FETUS
Rh antigens MAY DIFFUSE THRU PLACENTA TO
MOTHERS BLOODSTREAM
OVER TIME MOTHER WILL DEVELOP anti-Rh
antibodies IN RESPONSE
THE 1ST CHILD WILL BE BORN BEFORE BEING
AFFECTED BY antibodies
A 2ND Rh-positive FETUS MAY RECEIVE anti-Rh
antibodies FROM THE MOTHER
IF THIS OCCURS THE FETUS’S RBC WILL BE
DESTROYED IF NOT CAUGHT BY DOCTORS
• If mothers anti-rh
antibodies cross the
placenta to the 2nd fetus
then agglutination will occur
= Erythroblastosis Fetalis
or Hemolytic Disease
• The child will suffer from
anemia & hypoxia (lack of
o2) = brain damage or death
– Unless a blood
transfusion is performed
before birth which will
provide more rbc for o2
transport
• If a 1st time pregnant
woman knows she is rhpositive she can avoid
sensitization by receiving
medical treatment with
rhogam
Blood Vessels
Arterial Supply of the Brain
Figure 11.13
• Carotid &
subclavian
arteries
supply head &
neck w/blood
• Carotid is
the major
supplier &
branches into
external &
internal
• Right subclavian artery
originates from
brachiocephalic artery
• Left subclavian artery
originates from aortic
arch
– They branch into vertebral
arteries & thyrocervical
arteries
• Vertebral art. = Pass
upward toward the
foramina of the cervical
vertebrae
Figure Right subclavian arteriogram shows
an aneurysm arising from the thyrocervical
trunk (arrow).
• Thyrocervical art.
Extend short distance
to tissues in neck which
branch to supply:
• Thyroid glands
• Parathyroid
• Larynx
• Trachea
• Esophagus
• Pharynx
• Muscles of head & neck
Systemic Veins
• Large vessels that
are formed by
convergence of
smaller veins &
venules
• Toward heart
• Right atrium final
destination
• Superior & inferior
vena cava
Some veins don’t go to inferior vena cava but toward liver
HEPATIC PORTAL VEIN
ORIGINATE FROM DIGESTIVE TRACT
HEPATIC PORTAL SYSTEM SHUTS BLOOD
FROM CAPILLARIES OF DIG. TRACT TO CAP. OF LIVER
SUPERIOR MESENTERIC VEIN
INFERIOR MESENTERIC VEIN
LIVER
•Liver receives blood from 2 sources:
•Hepatic Portal Vein
•Hepatic Artery
•Blood that is high in O2 enters
hepatic artery
•Blood low in O2 enters hepatic
portal vein
• Venous blood from dig
organs is low in O2 but
still carries nutrients
absorbed by intestines
• Blood passes slowly thru
capillaries in liver
hepatic cells remove
materials used for
metabolic functions
phagocytic cells eliminate
bacteria etc that
penetrate dig. lining
• Blood passes thru liver
cap collected by small
veins that lead into
hepatic veins  emptied
into inferior vena cava
Circulation to the Fetus
Blood Transport Routine
Taking blood (Aorta)to the tissues and back (Vena Cavas)
–
–
–
–
–
Arteries
Arterioles
Capillaries
Venules
Veins
Congestive Heart Failure
• Causes of CHF
– coronary artery disease,
hypertension, MI, valve
disorders, congenital defects
• Left side heart failure
– less effective pump so more
blood remains in ventricle
– heart is overstretched &
even more blood remains
– blood backs up into lungs as
pulmonary edema
– suffocation & lack of oxygen to the
tissues
• Right side failure
– fluid builds up in tissues as
peripheral edema
Clinical Problems
• MI = Myocardial Infarction
– death of area of heart
muscle from lack of O2
– replaced with scar tissue
– results depend on size
& location of damage
• Blood Clot
– use clot dissolving
drugs streptokinase
or t-PA & heparin
– balloon angioplasty
• Angina Pectoris
– heart pain from ischemia of
cardiac muscle
Myocardial Infarction
• Myocardial infarction means
heart attack, or coronary
thrombus.
• Infarction = death of
muscle, tissue or organ
as a result of a
blockage of the blood
supply
• Blockage due to plaque
buildup in arteries
because of high cholesterol
and saturated fats in diet
Bypass Surgery
By-Pass Graft
Percutaneous
Transluminal
Coronary
Angioplasty
Stent in an Artery
• Maintains patency of blood vessel
What's an Artificial Pacemaker?
•“Artificial pacemaker" is a small, battery-operated device that helps the
heart beat in a regular rhythm by sending electrical impulses to the heart to
help it pump properly
•An electrode is placed next to the heart wall and small electrical charges
travel through the wire to the heart.
•Most pacemakers are demand pacemakers.
•They have a sensing device
•It turns the signal off when the heartbeat is above a certain level
•It turns the signal back on when the heartbeat is too slow.
• As the blood is pumped back to the heart, veins act as oneway valves to prevent the blood from flowing backwards.
• If the one-way valve becomes weak, some of the blood can
leak back into the vein, collect there, and then become
congested or clogged.
•This congestion will cause the vein to abnormally enlarge.
These enlarged veins can be either vericose or spider veins.
•Lack of oxygen in the blood causes a bluish discoloration in
the skin or mucous membranes called cyanosis.
•Most cyanosis is seen as a result of congenital heart disease,
pulmonary disease, or as a terminal event as in cardiopulmonary
arrest.
Desirable Levels of Blood Cholesterol
for Adults
• TC (total cholesterol)
under 200 mg/dl
• LDL under 130 mg/dl
• HDL over 40 mg/dl
• Normally,
triglycerides are in the
range of 10-190 mg/dl.
• Among the therapies
used to reduce blood
cholesterol level are
exercise, diet, and
drugs.
Exercise and the Heart
• Sustained exercise
increases oxygen demand in
muscles.
• Benefits of aerobic
exercise (any activity that
works large body muscles
for at least 20 minutes,
preferably 3-5 times per
week) are;
– increased cardiac output
– increased HDL and
decreased triglycerides
– improved lung function
– decreased blood pressure
– weight control.