Diagram of the Heart
this diagram
of the heart is licensed under the wikimedia graphic license
Inferior Vena Cava
The inferior vena cava is a large vein ascending
through the abdomen. It collects blood from the hepatic veins, the
lumbar veins, gonadal veins, renal veins, and phrenic veins. These
vessels usually drain regions that are supplied by arteries with
corresponding names. The inferior vena cava enters the heart through
the right atrium.
Aorta
The largest artery in the body, the aorta arises
from the left ventricle of the heart, goes up (ascends) a little
ways, bends over (arches), then goes down (descends) through the
chest and through the abdomen to where ends by dividing into two
arteries called the common iliac arteries that go to the legs.
Anatomically, the aorta is traditionally divided
into the ascending aorta, the aortic arch, and the descending aorta.
The descending aorta is, in turn, subdivided into the thoracic aorta
(that descends within the chest) and the abdominal aorta (that descends
within the belly).
The aorta gives off branches that go to the head
and neck, the arms, the major organs in the chest and abdomen, and
the legs. It serves to supply them all with oxygenated blood. The
aorta is the central conduit from the heart to the body.
Pulminary artery
When the muscular wall of the right ventricle contacts,
the blood inside the heart chamber is put under more pressure, and
the tricuspid valve closes. As a result, the only exit is through
the "pulmonary trunk," which divides to form the right
and left "pulmonary arteries." At the base of this trunk
is a "pulmonary semilunar valve" that is made up of three
leaflets or cusps. This valve opens when the right ventricle contracts.
When the right ventricular muscles relax, blood starts back up the
pulmonary trunk, causing the valve to close to prevent the flow
from returning into the ventricular chamber. The pulmonary vein
travels parallel to the pulmonary artery as it carries the blood
back up to the heart.
Pulminary vein
The pulmonary vein travels parallel to the pulmonary
artery as it carries the blood back up to the heart.
Superior Vena Cava
The superior vena cava is a great vein within the
thorax which drains from all the territories above the diaphragm
except those drained by the pulmonary arteries. It drains to the
right atrium of the heart.
The SVC is drained into by the:
- right brachiocephalic vein
- left brachiocephalic vein
- azgous vein
Tricupsid Valve
The tricuspid valve lies between the right atrium
and the right ventricle. It prevents backflow of blood from the
ventricle into the atrium. The valve may become damaged or diseased
causing stenosis and/or regurgitation of the valve. Both of these
complications may prevent the valve from functioning correctly
Right Ventricle
The right ventricle receives de-oxygenated blood
as the right atrium contracts. The pulmonary valve leading into
the pulmonary artery is closed, allowing the ventricle to fill with
blood. Once the ventricles are full, they contract. As the right
ventricle contracts, the tricuspid valve closes and the pulmonary
valve opens. The closure of the tricuspid valve prevents blood from
backing into the right atrium and the opening of the pulmonary valve
allows the blood to flow into the pulmonary artery toward the lungs.
Left Ventricle
The left ventricle receives oxygenated blood as
the left atrium contracts. The blood passes through the mitral valve
into the right ventricle. The aortic valve leading into the aorta
is closed, allowing the ventricle to fill with blood. Once the ventricles
are full, they contract. As the left ventricle contracts, the mitral
valve closes and the aortic valve opens. The closure of the mitral
valve prevents blood from backing into the left atrium and the opening
of the aortic valve allows the blood to flow into the aorta and
flow throughout the body.
Mitral Valve
The mitral valve separates the left atrium from
the left ventricle. It opens to allow the oxygenated blood collected
in the left atrium to flow into the left ventricle. It closes as
the left ventricle contracts, preventing blood from returning to
the left atrium; thereby, forcing it to exit through the aortic
valve into the aorta.
Aortic Valve
The aortic valve separates the left ventricle from
the aorta. As the ventricles contract, it opens to allow the oxygenated
blood collected in the left ventricle to flow throughout the body.
It closes as the ventricles relax, preventing blood from returning
to the heart.
The Heart
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Heart
