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The right superior lobar (secondary) bronchus
is known as the eparterial
(above the artery) bronchus because it passes above the level of the pulmonary
artery. All others are the hyparterial bronchi.
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The cervical pleura (cupula) is the dome of the
pleura, projecting into the neck above the neck of the first rib. It is
reinforced by Sibson's
fascia (suprapleural membrane), which is a thickened portion of the
endothoracic fascia, and is attached to the first rib and the transverse
process of the seventh cervical vertebra.
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Visceral pleura (pulmonary pleura) is supplied
by bronchial arteries, but its venous blood is drained by pulmonary veins.
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Pancoast's or superior pulmonary sulcus tumor: is
a malignant neoplasm of the lung apex and causes Pancoast's syndrome, which
comprises (1) lower trunk brachial plexopathy (which causes severe pain
radiating toward the shoulder and along the medial aspect of the arm and
atrophy of the muscles of the forearm and hand) and (2) lesions of cervical
sympathetic chain ganglia with Horner's syndrome (ptosis, enophthalmos, miosis,
anhidrosis, and vasodilation).
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Superior pulmonary sulcus: is a deep vertical
groove in the posterior wall of the thoracic cavity on either side of the
vertebral column formed by the posterior curvature of the ribs, lodging the
posterior bulky portion of the lung.
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Bronchopulmonary segment is the anatomic,
functional, and surgical unit (subdivision) of the lungs.
Consists of a
segmental (tertiary or lobular) bronchus, a segmental branch of the pulmonary
artery, and a segment of the lung tissue, surrounded by a delicate connective
tissue septum (intersegmental septum). It is drained by the intersegmental part
of the pulmonary vein.
Refers to the
portion of the lung supplied by each segmental bronchus and segmental artery.
The pulmonary veins are said to be intersegmental.
Is clinically
important because the intersegmental pulmonary veins form surgical landmarks;
thus, a surgeon can remove a bronchopulmonary segment without seriously
disrupting the surrounding lung tissue and major blood vessels.
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Bronchopulmonary segments of
right lung
"A PALM Seed Makes Another Little Palm":
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In order from superior to inferior: Apical
Posterior Anterior Lateral Medial Superior Medial basal Anterior basal Lateral basal Posterior
basal
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Bronchial arteries arise from the thoracic aorta;
usually there is one artery for the right lung and two for the left lung.
Bronchial veins
Receive blood from the bronchi and empty into the azygos vein on the right and into the
accessory hemiazygos vein or the superior intercostal vein on the
left.
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Phrenic Nerve Runs anterior to the root of the
lung, whereas the vagus nerve runs posterior to the root of the
lung.
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Transverse sinus is a subdivision of the
pericardial sac, lying posterior to the ascending aorta and pulmonary trunk,
anterior to the SVC, and superior to the left atrium and the pulmonary veins.
Is of great importance to the cardiac surgeon because,
while performing surgery on the aorta or pulmonary artery, a surgeon can pass a
finger and make a ligature through the sinus between the arteries and veins,
thus stopping the blood circulation with the ligature.
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Right Atrium Contains the valve (eustachian) of the IVC
and the valve (thebesian) of the coronary sinus.
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Septomarginal trabecula (moderator band) Is an
isolated band of trabeculae carneae that forms a bridge between the
intraventricular (IV) septum and the base of the anterior papillary muscle of
the anterior wall of the right ventricle.
Is called the moderator band for its
ability to prevent overdistention of the ventricle and carries the right limb
(Purkinje fibers) of the atrioventricular (AV) bundle from the septum to the
sternocostal wall of the ventricle.
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Bicuspid (left AV) valve is called the mitral valve
because it is shaped like a bishop's miter.
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CoArctation of Aorta leads to the development of
the important collateral circulation over the thorax, which occurs between the
(1) anterior intercostal branches of the internal thoracic
artery and the posterior intercostal arteries
(2) superior epigastric branch of the internal thoracic
artery and the interior epigastric artery
(3) superior intercostal branch of the costocervical trunk
and the third posterior intercostal artery
(4) posterior
intercostal arteries and the descending scapular (or dorsal scapular) artery,
which anastomoses with the suprascapular and circumflex scapular arteries around
the scapula.
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White rami communicantes
Contain
preganglionic sympathetic GVE (myelinated) fibers with cell bodies located in
the lateral horn (intermediolateral cell column) of the spinal cord and GVA
fibers with cell bodies located in the dorsal root ganglia.Are connected to the
spinal nerves, limited to the spinal cord segments between T1 and L2.
Gray rami communicantes
Contain
postganglionic sympathetic GVE (unmyelinated) fibers that supply the blood
vessels, sweat glands, and arrector pili muscles of hair follicles.Are
connected to every spinal nerve and contain fibers with cell bodies located in
the sympathetic trunk.
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Specialized cardiac muscle cells, which form the
sinoatrial (SA) node, are the
pacemakers of the heart. They have the fastest-paced autorhythmicity of all
cardiac muscle cells and are located in the wall of the right atrium near the
opening of the superior vena cava. Specialized cardiac muscle cells forming the
atrioventricular node are also located in the
wall of the right atrium, but near the interatrial wall and the opening of the
coronary sinus.
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The upper two
posterior intercostal arteries arise from the costocervical trunk;
the remaining arteries arise from the descending thoracic aorta. The posterior
intercostal arteries anastomose with the anterior
intercostal arteries, which arise from the internal thoracic artery.
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Both the aortic
and pulmonary valves have right and left cusps. Remember that the
aortic valve has a right and left cusp, but also a posterior cusp, since it is
more posterior. In contrast, the pulmonary valve has both right and left cusps
and an anterior cusp since it is more anterior (each
semilunar valve has the single cusp that the first letter of its name does not
have); aortic has posterior; pulmonary has anterior. This also
reminds you that the aorta is posterior to the pulmonary trunk. Also remember
that the right ventricle is the more anterior chamber and thus gives off a more
anterior great vessel. The left ventricle is the more posterior chamber as it
gives off its outflow tract. As the great vessels proceed cranially, the aorta
ends up on the left as it arches over the split of the pulmonary arteries.
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The papillary
muscles attach the chordae tendineae to the heart wall and provide an important
dynamic mechanism to ensure the competence of the valves. During the ejection
phase of ventricular systole, shortening of the papillary muscle compensates
for the decrease in the ventricular chamber size and thereby, prevents eversion
of the atrioventricular valve leaflets, thereby preventing regurgitation during
ventricular systole.
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The sympathetic cardiac accelerator fibers,
affecting primarily the ventricles, are derived from the superior, middle, and
inferior cervical ganglia (cervical cardiac nerves) as well as from the upper
four thoracic ganglia (thoracic cardiac nerves), whence they converge on the
cardiac plexus before reaching the heart.
Having traversed these ganglia, the fibers gain access
(via the white rami communicantes) to the upper four thoracic spinal nerves and
the corresponding levels of the spinal cord.
Parasympathetic
fibers derived from CN X and its
recurrent laryngeal branch decrease heart rate and stroke volume through
release of acetylcholine, principally in the vicinity of the sinuatrial node.
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