2. External heart
This is the external
appearance of a normal
heart.
The epicardial surface is
smooth and glistening.
The amount of epicardial fat
is usual.
The left anterior descending
coronary artery extends
down from the aortic root to
the apex.
3. The Heart – Exterior Structures
It's small, a little larger than a
clenched fist. Relatively simple in
function, your heart's primary
purpose is to pump...24 hours a
day, 70 to 80 times a minute.
With each beat, the heart pumps
blood that delivers life-sustaining
oxygen and nutrients to 300 trillion
cells.
Each day the average heart
"beats" (or expands and contracts)
100,000 times and pumps about
2,000 gallons of blood. In a 70-
year lifetime, an average human
heart beats more than 2.5 billion
times, pumping approximately 1
million barrels of blood
4. Interior
The circulatory system is a network
of flexible tubes through which blood
flows as it carries oxygen and
nutrients to all parts of the body.
It includes the heart, lungs, arteries,
arterioles (small arteries) and
capillaries (minute blood vessels).
It also includes venules (small veins)
and veins, the blood vessels
through which blood flows as it
returns to the heart.
If all these vessels were laid end-to-
end, they would extend for about
60,000 miles--far enough to encircle
the earth more than twice.
5. Aortic valve
The aortic valve shows
three thin and delicate
cusps. The coronary artery
orifices can be seen just
above.
The endocardium is
smooth, beneath which can
be seen a red-brown
myocardium.
The aorta above the valve
displays a smooth intima
with no atherosclerosis.
6. Tricuspid valve
This is the tricuspid
valve. The leaflets and
thin and delicate. Just
like the mitral valve, the
leaflets have thin
chordae tendineae that
attach the leaflet
margins to the papillary
muscles of the
ventricular wall below.
