Download HEART internal structure

HEART ANATOMY
The Heart Wall
serous membrane
• A serous membrane consists of a single layer of
flattened mesothelial cells applied to the surface of
a thin layer of collagenous tissue that attaches to
underlying fascia.
• The mesothelium of the serous membrane forms
the lining of a closed serous membrane cavity.
• Serous membrane lining the wall of a serous cavity
is designated parietal while that covering viscera is
called visceral.
• Connecting serous membrane runs between
parietal and visceral components.
• The myocardium. Note the endocardial layer, which
consists of endothelium supported by a rather thick
layer of subendocardial connective tissue (green). The
ventricular lumen is indicated.
Valve
Lumen
HEART ANATOMY (EXTERNAL VIEW)
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The heart is a complex
muscular pump that
maintains oxygen and blood
circulation through the lungs
and the rest of the body
through Both the systemic
and the pulmonary
cerculations.
The heart pumps about
7200 liters/day.
Is about the size of you
clenched fist
the Heart
ANTERIOR SURFACE
the Heart,
POSTERIOR SURFACE
Internal Anatomy and Organization
– Atria – separated by the interatrial septum
– Ventricles – separated by the interventricular septum
– Atrioventricular valves extend into the openings
between the atria and ventricles permitting the blood to
flow in one direction only.
– Contraction of the papillary muscles prevent the
atrioventricular valves from folding back into the atria.
Right Atrium
– Receives blood from the superior vena cava
(head, neck upper limbs, chest) inferior vena
cava (rest of the trunk, lower limbs, and
viscera), and coronary veins of the heart
through the coronary sinus.
– Oval impression – Fossa Ovalis
– Contains pectinate muscles with trabecule
The Right Atrium
The distinction between the posterior
Smooth walled and the anterior trabeculated
appendage.
The junction between the two is marked by
The formed muscle bundle, the crista
terminalis.
The trabeculae tend to run at right angles
to the crista.
The inside of the right atrial chamber
presents a
The posterior surface, a septal surface,
and an anterior surface.
The floor of the chamber can be
considered as tricuspid valve
orifice orientated obliquely to the right
The inferior vena cava opens into the
junction of the posterior wall
And the floor.
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FO
Septal
IVC
Right Atrium, Extensive trabecular pouch found
beneath the orifice of the inferior vena cava
(the so-called sub-eustachian sinus).
IVC
SES
http://www.rjmatthewsmd.com/Definitions/anatomy_ofthe_heart.htm
Right Ventricle
– Blood flows from the right atrium to the right ventricle through the
cusps of the right atrioventricular valve known as the tricuspid
valve.
– The tricuspid valve is attached by long tendons called chordae
tendineae to the papillary muscles.
– When the right ventricle contracts, the tricuspid closes
preventing blood from entering the right atrium. The chordae
tendineae keep the tricuspid from folding back into the right
atrium.
– Blood exits the right ventricle through the conus anteriosus as
the pulmonary semilunar valve opens into the pulmonary trunk
dividing into the right and left pulmonary arteries leading to the
lungs.
The Right
ventricle
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Left Atrium
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Smaller than right atrium
Thicker walls than right atrium
2 left & 2 right pulmonary veins
Oval impression – Fossa Ovalis
Atrial Appendage (longer & narrower)
– Receives oxygen rich blood from the two right
and two left pulmonary veins.
– Blood passes from the left atrium to the left
ventricle through the left atrioventricular valve or
bicuspid.
Left Atrium
• The left atrium is rather smaller than the right, but its
walls are thicker, measuring about 3 mm it consists,
like the right,
• of two parts, a principal cavity and an auricula.
– The principal cavity is cuboidal in form, and concealed, in
front, by the pulmonary artery and aorta; in front and to the
right it is separated from the right atrium by the atrial
septum; opening into it on either side are the two pulmonary
veins.
– The auricula is somewhat constricted at its junction with the
principal cavity; it is longer, narrower, and more curved than
that of the right side, and its margins are more deeply
indented. It is directed forward and toward the right and
overlaps the root of the pulmonary artery. 35
The Left Atrium of the
Heart (Principle Part)
Left Ventricle
• Oval shaped
• Larger than right
• Walls 3 X thicker than
right
• Smooth walls
• Papillary muscles
• Cordae tendinae
• Contractions causes the bicuspid to close keeping the blood from
backing up in the left atrium; distance between the apex and base
increases; diameter of the ventricle chambers decrease.
– Blood exits through the semilunar valve into the ascending
aorta.
– Right and left coronary arteries originate at the aortic sinuses
and deliver blood to the heart.
– Blood passes into the descending aorta and into the systemic
circuit.
Valves of the Heart
The heart has four valves for:
Pumping action of the heart.
Maintaining unidirectional blood flow.
Tricuspid Valve
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Bicuspid
“Mitral”
Valve
Oblique section (left)
Mitral Valve
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2 triangular leaflets
Larger, thicker, stronger than
tricuspid
• Anterior leaflet (aortic or
septal)
• Posterior leaflet (ventricular)
• Papillary muscle – contraction
occurs during systole to
shorten Cordae Tendinae
– prevent MR during
ventricular systole
Tricuspid valve
• 3 triangular shaped leaflets
• Names
– Anterior
– Septal
– Posterior
• Papillary muscles & chordae
tendinae are present but play a
more important role in the high
pressure chamber of LV
Pulmonary semi-lunar
valve
Lt. Atrium
Aortic semi-lunar valve
Pulmonary Valve
Aortic Valve
Aortic Simi lunar
Valve
Aortic valve
Pulmonary valve
• 3 Semi-lunar cusps
• Semi lunar shape
• Attached to a fibrous ring
within the wall of
pulmonary trunk
• Orientation:
– Left anterior
– Right anterior
– Posterior
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3 Similar to pulmonary
Leaflets - 3
Semi lunar shape
Attached to a fibrous ring within
the wall of wall of aortic artery
• Orientation
– Anterior
– Left posterior
– Right posterior
Skeleton of the heart valves
Diastole
Systole