4. System Overview
The circulatory
The circulatory
system uses the
system uses the
heart as a
heart as a
pump and
pump and
transports
transports
through blood
through blood
vessels to
vessels to
organs and the
organs and the
smallest
smallest
tissues and
tissues and
cell
cell
6. Cardiovascular
System
Veins differ from arteries
because they carry
blood toward heart,
have valves, and have
thinner walls; they are
more numerous and have
larger capacity
11. The Heart
3 layers to heart:
•Outer: Epicardium
•Middle: Myocardium
•Inner endocardium
12. The Heart
Although heart is one
single organ, it is easier
to understand if you
think of it as two
pumps working
together
.
13. The Heart
Right side collects
blood from body and
sends it to lungs; left
side collects blood
from lungs and sends
it to rest of body
.
14. Chambers of the
Heart
Four chambers in
heart
Two chambers on left
side are separated
from two chambers
on right side by wall
called septum
15. Septums of the Heart
Wall between
upper, smaller
chambers (atria)
is interatrial
septum
Wall between two
larger chambers
(ventricles) is
interventricular
septum
17. Flow of blood through
the Heart
Two large veins
that return blood
from the body to
right atrium are
superior (SVC)
and inferior (IVC)
vena cava
18. Flow of blood through
the Heart
Right atrium (RAtr)
(locations are
based on patient’s
perspective) is
collecting chamber
where blood is
returned to heart
after trip around
the body
FIRST
19. Flow of blood through
the Heart
Blood travels from
right atrium,
through one-way
atrioventricular
valve called
tricuspid valve
(TCVa) , and into
right ventricle
(RVe)
20. Flow of blood through
the Heart
When right ventricle
is full of blood, heart
contracts; tricuspid
valve prevents
backflow and so
blood flows through
pulmonary valve
(PVa) to pulmonary
arteries (PA)
Second
21. Flow of blood through
the Heart
Right pulmonary
artery (PA)* goes
to right lung, left
pulmonary artery
(PA) goes to left
lung
*Remember: Arteries go
AWAY from the heart
THIRD
22. Flow of blood through
the Heart
Vessels then get
smaller and
smaller,
eventually
ending in
capillaries
around each air
sac (alveolus);
23. Flow of blood through
the Heart
Blood then returns
to heart via left
(LPV) and right
pulmonary (RPV)
veins*
*Remember: Veins go
TOWARD the heart
24. Flow of blood through
the Heart
Pulmonary veins
return blood to left
atrium (LAtr).
Blood flows through
atrioventricular
valve, called mitral
valve (MiVa) , and
into left ventricle
(LVe)
Fourth
25. Flow of blood through
the Heart
Ventricular pressure
increases as it fills,
and heart
contracts forcing
mitral valve closed,
blood is ejected
through aortic
valve (Ava) to
aorta, and then out
to rest of body
Fifth
27. Flow of Blood through
the Heart
Blood is
ejected
during
systole, or
contraction (of
ventricles)
phase
28. Flow of Blood through
the Heart
Both atria fill at
same time, both
ventricles fill at
same time, and
both ventricles
eject blood at
same time when
heart contracts
29. Flow of Blood through
the Heart
After blood is
ejected from
ventricles, heart
enters resting
period called
diastole
During diastole,
ventricles fill
with blood
30. Flow of Blood through
the Heart
Contraction
begins at
apex and
travels
upward
31. Flow of Blood through
the Heart
Valve located at
exit to each
chamber because
the circulatory
system is a
pressurized system
and valves
prevent any
ejected blood
from flowing
backwards
32. Measuring Heart Rate
Heart rate is
measured by
counting rhythmic
expansion and
contraction of
arteries due to
opening & closing
of the aortic
semilunar valves
34. The Heart
Atrial walls are
thinner than
ventricular walls
Higher
pressures are
generated in
ventricles to
move blood
throughout entire
body
THIN WALL
THICK WALL
35. Coronary Arteries
Portion of newly
oxygen-enriched
blood leaving
heart is diverted
from aorta by
right and left
coronary
arteries
36. Figure 12-4
Coronary circulation.
Regular aerobic
exercise improves the
ability of the heart to
increase the density
(number of vessels in
one area) of blood
vessels that branch
from the main
coronary arteries.
37. Coronary Circulation
By increasing the
density of blood
vessels that branch
off the main arteries,
there will be
alternate routes for
blood to travel in
case of a blockage
and decrease risk
of myocardial
infarction
38. Figure 12-6
Atherosclerosis.
Fatty deposits called plaque
develop on the inside of the
blood vessels and restrict
flow
Mainly the aorta, coronary
arteries and cerebral
arteries are effected
Why do you think this is?
41. Electrical System of
the Heart
Cardiac muscle is
auto rhythmic,
meaning it can
contract
without nerve
impulses or
hormones
42. Electrical System of
the Heart
There are
specialized
cardiac cells that
create and
distribute
electrical current
that causes
controlled and
directed
contraction of
heart
43. Electrical System of
the Heart
Nodal cells, or
pacemaker cells,
are specialized cells
that not only
create electrical
impulse, but
create impulses at
regular interval
45. The Electric Pathway
Sino atrial node
sends impulse to
atrio ventricular
node before AV
node can send
signal
46. The Electric Pathway
However, atrio
ventricular node
acts as backup if
sinoatrial node fails to
fire, resulting in
slower heartbeat
due to reduced firing
rate
47. Figure 12-9
Conduction system of the
heart.
•• SA node causes
SA node causes
atria to contract
atria to contract
•• Stimulus arrives
Stimulus arrives
at AV node
at AV node
•• Follows AV
Follows AV
bundle and
bundle and
travels through
travels through
apex branches
apex branches
•• Purkinjie fibers
Purkinjie fibers
stimulate
stimulate
ventricles to
ventricles to
contract
contract
51. EKG & Electrical Activity
EKG represents
Normal
•P wave-impulse generated
by SA node, atria contract
•QRS wave-Depolarization
of ventricles right before
ventricles contract
•T wave-repolarization of
ventricles when they are at
rest before next beat
59. Heart Attack & CPR
CPR consists of artificial
blood circulation & artificial
respirations. It’s purpose is
to maintain a flow of
oxygenated blood to the
brain and heart
Watch video on “Myocardial Infarction”
61. Blood Vessels
Blood leaves heart
through aorta,
which branches into
large vessels called
arteries
Arteries divide into
smaller and smaller
vessels, smallest of
which are called
arterioles
62. Blood Vessels
Arterioles feed into
capillaries that
form capillary beds
in body's tissues,
allowing oxygen
and nutrients to
infuse into cells
and picking up
carbon dioxide
and waste
products for
removal
63. Blood Vessels
Diameter of only
0.008 mm (slightly
larger than
diameter of single
red blood cell) Allow
easy movement
of oxygen and
nutrients through
wall, while carbon
dioxide and
wastes can move
into blood
64. Blood Vessels
Blood then makes
its return trip to the
heart by draining
into tiny venules,
which combine into
veins which
eventually become
great veins (SVC
and IVC) that
return to heart
68. Figure 12-16
Blood pressure measurement.
Done with a
stethoscope and
sphygmomanometer
an inflatable cuff
placed around the arm,
so that when it is
inflated, it squeezes
brachial artery shut
69. Figure 12-16
Blood pressure measurement.
Stethoscope placed
over artery near elbow
and cuff inflated until
30 mm Hg past the
point that pulse no
longer heard.
Open release valve
slightly
70. Figure 12-16
Blood pressure measurement.
Listen for sound of blood
coming through artery,
which is the peak
systolic pressure (top
number)
Cuff pressure
decreases until sound is
not heard. The last sound
is diastolic pressure
(lower number)
71. Elevated Blood Pressure
Desirable blood pressure is:
•Systolic - from 90 to 119
•Diastolic - from 60 to 79
Prehypertension is:
•Systolic-from 120 to 139
•Diastolic- from 80- 89
Hypertension is:
•Systolic over 140
•Diastolic over 90
72. Plugging the “Leaks” of
Blood Vessels
CV system is closed
and pressurized
system
If break or leak in
system couldn't be
stopped, you would
lose large amount of
blood
Several substances in
blood plug leaks
Fibrin traps blood cells and
platelets to form blood clot
73. Plugging the “Leaks” of
Blood Vessels
When inner wall of
vessel is damaged,
underlying collagen
fiber becomes
exposed
Platelets floating in
blood begin to attach
to that rough
damaged site
74. Plugging the “Leaks” of
Blood Vessels
Attached platelets
release several
chemicals that draw
more platelets,
creating platelet plug
76. Clotting Process
Fibrin forms netlike
patch at site of
injury, snagging
more blood cells
and platelets;
within 3 to 6
minutes a clot is
created
Fibrin traps blood cells and
platelets to form blood clot
77. Clotting Process
Once clot is formed,
it begins to retract
and pulls edges of
damaged tissue
together allowing
edges to
regenerate
necessary
epithelial cells to
make permanent
repair over time
79. WEAR YOUR ASSIGNED
COLOR
Meet here at Room 108 on
Thursday and we’ll go to room
over in AAR building for
exercise
Complete Handout “Heart
Activity” as you will need to
hand that in at the end of
Thursday’s class for credit
80. “The Heart Activity”
Work on the handout
“The Heart Activity”
Read through the first
two pages on the
Blood Flow
Sequence. The third
page shows structure
of the heart.
Complete the 15
questions on back
page
