Download Heart 2: Chambers

Heart 2: Chambers
Heart 1. Introduction to the Heart
Chambers of the Heart
The heart is composed of four well separated chambers. The two superior chambers are the
atria (= entry halls) , and the two inferior chambers are the ventricles (= little bellies). The atria
are the receiving chambers, they receive venous blood from systemic and pulmonary circulation
and pump it down into the ventricles. The ventricles are the distributing chambers, they pump
blood out of the heart into the peripheral circulation.
The Atria
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Heart 2: Chambers
The
there
is
aatria
wrinkled
are
the
pouch
thin-walled
like
structure
known
ofslightly
the
as
an
heart.On
the
anterior
surface
of
each
atrium,
auricle
that
its
resemblance
ittwo
can
hold
ademarcating
to
greater
a dog's
volume
ear.
Each
of
blood.
auricle
increases
(auri
the
=well
capacity
ear),
so
ofwall
named
each
atrium
because
so of
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The
right
atrium
through
receives
Deoxygenated
blood
from
systemic
as
coronary
circulations
Superior
&
Inferior
Vena
cavae
and
coronary
sinus,
The
shows
ridges
right
called
two
atrium
basic
the
is
divisions,
composed
a
smooth
ofright
achambers
main
posterior
cavity
and
part
an
and
auricle.
an
anterior
Internally,
part
lined
the
by
horizontal
ofrespectively.
this
chamber
pectinate
muscles.
fine
margin
the
two
parts
of
the
wall
isits
known
as
the
crista
terminalis.
left
atrium
receives
Oxygenated
blood
from
pulmonary
circulation
through
four
y
veins
Pulmonar
from
auricle.
of
The
heart.
four
each
Th
The
pulmonary
lung).
eleft
interior
atrium
Similar
veins
of isthe
tosituated
open
the
left
atrium
into
behind
atrium,
the
is
atrium
smooth,
the
the
right
through
left
but
atrium
atrium
the
left
and
consists
posterior
auricle
forms
of
possesses
wall.
the
a as
main
greater
cavity
muscular
part
and
of
the
an
ridges.
base
(2
The Ventricles
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Heart 2: Chambers
The
right
ventricle
pumps
deoxygenated
to the
lungs
through
the
pulmonary
trunk.
pulmonary
trunk
The
into
oxygenated
right
and
blood
left
pulmonary
towards
body
arteries,
through
going
the
tolargest
the
right
artery,
and
left
lungs.
left
pumps
Aorta.
Internally,
the
walls
of both
ventricles
areblood
marked
by
irregular
ofThe
muscles,
called
ae
carneae.
trabecul
Another
group
ofsplits
cone-shaped
muscles,
the
papillary
muscles
are
projecting
into
the
ventricular
cavities
from
the
walls
for the
theridges
attachment
of ventricle
chordae
tendineae
the
valve
leaflets
.to
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Heart 2: Chambers
The
thickness
ofthe
the
myocardium
into
chamber’s
the
adjacent
function.Therefore,
ventricles.
both
the
of
all
atria
the
are
four
thin-walled
chambers
they
heart
only
varies
have
according
to
pump
to
blood
each
Because
atria.
the
ventricles
pump
blood
to
greater
distances,
their
are
thicker
than
those
of the
Although
volumes
distance
pumps
to
ventricle
blood
flow
of
to
is
considerably
blood,
maintain
the
is
right
great
lungs
much
the
and
distances
the
at
larger
right
left
lower
same
thicker
ventricles
side
and
to
pressure:
rate
than
has
all
theother
of
a
left
act
the
blood
much
the
ventricle
as
wall
parts
two
resistance
flow.
lighter
of
ofseparate
the
the
has
Therefore,
workload.
right
body
to
towork
ventricle.
pumps
blood
atas
the
aof
much
Itwalls
higher
only
flow
muscular
thatharder
pumps
issimultaneously
pressure.The
small.
wall
than
blood
The
of
the
the
left
a right
short
resistance
eject
left
ventricle
equal
In
cavity
cross
isblood
section,
circular.
right
ventricular
cavity
is
roughly
crescent
shaped,
while,
the
left
ventricular
Partitions or Septa of the Heart
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Heart 2: Chambers
The right and Left Atrial cavities are completely separated from each other by an ‘interatrial
septum’
. The
septum runs from the anterior wall of the heart backward and to the right. The right atrial surface
of the septum shows a smooth depression known as
Fossa Ovalis,
representing the spot where an opening
,
the
foramen ovale,
existed in the fetal life.
The right and left ventricular cavities are separated by an interventricular septum which is
muscular in its lower part and membranous in its upper portion. This septum is placed obliquely,
with one surfacing forward and to the right and the other facing backward and to the left. The
upper membranous part of the septum is attached to the fibrous skeleton of the heart.
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Heart 2: Chambers
Question:
What are the consequences of old age on cardiac musculature and its performance ?
Proceed to Heart 3: Valves
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