Download Drawings of di ti f

Drawings of
di
dissections
ti
off
the human
heart by
Leonardo
DaVinci done
in 1510.
The anatomy lesson by Dr. Nicholas Tulp, by Rembrandt in 1632
Dr. Gunter Von
Hagens with
ppastinated human
cadaver at Body
Worlds exhibit in
2009
The heart is
between the
lungs and
beneath the
b
breastbone
b
(sternum).
Note the heart is only about one inch behind the breastbone!
The majority of the heart
wall is composed of
myocardium
di
The heart
has four
chambers
There are valves
Th
l
b t
between
the
th atria
t i andd ventricles
t i l andd valves
l
att
the exits from the ventricles.
tricuspid
p
Right side of heart
tricuspid
Chordae tendineae
Right side of heart
On left side of heart
The left AV valve
is also called the
“bicuspid valve”.
Another name for
this same valve is
the “mitral valve”
b
because
it looks
l k
like a Bishop’s
miter.
The AV valves
are passively
openedd by
b the
th
flow of blood
and close when
blood tries to
move
backwards. The
chordae
tendineae
support the
valves when they
are closed.
The chordae
t di
tendineae
support
the AV valves
when theyy are
closed.
Internal view of a ventricle showing the papillary muscles and
th chordae
the
h d tendineae.
t di
The semilunar valves, which lack chordae tendineae, are located
at the exits from the ventricles.
Pulmonary
semilunar valve
Semilunar valve in action
Semilunar
valve in action
Aortic semilunar valve
open
closed
pulmonary
artery
pulmonary
artery
Right side of
the heart is
the
p
pulmonary
y
pump. It is
a low
pressure
system.
The left
Th
l f side
id off
the heart is the
systemic
y
p
pump.
p
It is a high
pressure system
Since the left
ventricle has the
hardest jjob of all,,
its muscular wall is
thicker than that of
all the other
chambers.
The coronary arteries exit the aorta immediately past the aortic
semilunar valves and circle back to bring blood to the myocardium
Red blood cells in capillary
The venous drainage from the myocardium collects in the
coronary veins, which in turn flow to the coronary sinus which
drains into the posterior of the right atrium.
Atherosclerosis can lead
to narrowing of the
myocardial arteries. This
can cause myocardial
y
ischemia and angina
pectoris
Reduction of blood
flow through
g a branch
of the coronary arteries
causes pain (angina
pectoris)
Blockage of blood flow
through a branch of the
coronary arteries can
cause an area of the
myocardium to become
infarcted (myocardial
infarction or MI).
MI) This is
commonly called a “heart
attack”.
Severe pain and discomfort is associated with myocardial
infarctions (MIs, heart attacks)
Drugs and surgery cannot
rescue the cells in the
infarcted area, they die in
seconds. The purpose of
the drugs and surgery is to
rescue the nearby areas
with reduced blood supply
(i h i areas))
(ischemic
Coronary bypass
surgery may be
done to restore
normal circulation to
the myocardium.
Cross-section of the heart
showing
h i scarring
i from
f
pastt
heart attacks (white areas)
Streptococcal
throat infection
Microscopic view of Streptococcus pyogenes, the trigger for
rheumatic fever and rheumatic heart disease
Damaged
mitral valve in
rheumatic heart
disease
Damaged aortic
semilunar
il
valve
l in
i
rheumatic heart disease