Transcript Thorax

Thorax
Internal thoracic artery
descends into thorax
1.2cm lateral to edge of
sternum, and ends at the
sixth costal cartilage by
dividing musculophrenic
and superior epigastric
arteries
Azygos vein
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Begins as continuation of right
ascending lumbar vein
Ascending along the right side of
vertebral column
Joins superior vena cava by aching
above right lung root at level of T4 to
T5
Receives right posterior intercostals
and subcostal veins plus some of
bronchial, esophageal and pericardial
veins, and hemiazygos vein
Tributaries – hemiazygos v. and
accessory hemiazygos v., which
receive most left posterior intercostals
vein and left bronchial veins
The lymphatic drainage of thorax
The lymphatic drainage
of thoracic wall
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To axillary lymph nodes
To parasternal lymph nodes
(along internal thoracic
vessels)
To intercostals lymph nodes
from deeper structures
lymph nodes of the thoracic contents
lymph nodes of trachea,
bronchi and lungs
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Pulmonary lymph nodes lie in
the angles of bifurcation of
branching lobar bronchi
Bronchopulmonary hilar lymph
nodes －lie in the hilus of the
lung
Tracheobronchial lymph nodes
－situated above or below the
bifurcation of trachea
Paratracheal lymph nodes
－along each side of the trachea
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Anterior mediastinal
lymph node lies anterior
to the large blood vessels of
thoracic cavity and pericardium;
the efferents unite with those of
paratracheal lymph nodes, to
form the right and left
bronchomediastinal trunks.
The left bronchomediastinal
trunk terminates in thoracic duct,
and right in the right lymphtic
duct
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Posterior mediastinal
lymph nodes lie along the
esophagus and thoracic aorta
Anterior branches of thoracic nerves
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Intercostal nerves - (anterior rami of
T1- T11): runs forward inferiorly to
intercostals vessels in costal groove of
corresponding rib, between
intercostals externi and intercostals
interni; first six nerves are distributed
within their intercostals space, lower
five intercostals nerves leave anterior
ends of their intercostals spaces to
enter abdominal wall
Subcostal nerve - (anterior ramus of
T12): follows inferior border of T12 rib
and passes into abdominal wall
Distribution: distributed to intercostales
and anterolateral abdominal muscles,
skin of thoracic and abdominal wall,
parietal pleura and peritoneum
The segmental innervation of anterior
surface of trunk
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T2－sternal angle
T4－ nipple
T6－xiphoid process
T8－costal arch
T10－umbilicus
T12－midpoint between
umbilicus and symphysis
pubis
Phrenic nerve
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Descends over scalenus
anterior to enter thorax
Accompanied by
pericardiophrenic vessels and
passes anterior to lung roots
between mediastinal pleura
and pericardium to supply
motor and sensory
innervation to diaphragm
Sensory fibers supply to
pleurae, pericardium and
peritoneum of diaphragm;
usually right phrenic nerve
may be distributed on live,
gallbladder and biliary system.
Left vagus nerve
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Enter thoracic inlet between left
common carotid and left subclavian
arteries, posterior to left
brachiocephalic vein
Crosses aortic arch where left
recurrent laryngeal nerve branches
off
Passes posterior to left lung root
Forms anterior esophageal plexus
Forms anterior vagal trunk at
esophageal hiatus where it leaves
thorax and passes into abdominal
cavity , then divides into anterior
gastric and hepatic branches
Right vagus nerve
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Enter thoracic inlet on right side
of trachea
Travels downward posterior to
right brachiocephalic vein and
superior vena cava
Passes posterior to right lung
root
Forms posterior esophageal
plexus
Forms posterior vagal trunk at
esophageal hiatus where it
leaves thorax and passes into
abdominal cavity, then divides
into posterior gastric and celiac
branches
Recurrent laryngeal nerves
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Right one hooks around right
subclavian artery, left one hooks
aortic arch
Both ascend in tracheo-esophageal
groove
Nerves enter larynx posterior to
cricothyroid joint, the nerve is now
called inferior laryngeal nerve
Innervations: laryngeal mucosa
below fissure of glottis , all
laryngeal laryngeal muscles except
cricothyroid
Bronchial and esophageal
branches
Thoracic sympathetic trunk
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Branches of sympathetic trunk to
thoracic plexuses
Greater splanchnic nerve - formed by
preganglionic fibers from T5~T9 ganglia,
and relay in celiac ganglion.
Lesser splanchnic nerve - formed by
preganglionic fibers from T10~T12
ganglia, and relay in aorticorenal
ganglion.
The postganglionic fibers supply the liver,
spleen, kidney and alimentary tract as far
as the left colic flexure.
Regional anatomy of thorax
Parts and regions of the thorax
Boundaries
 Superior - jugular notch,
sternoclavicular joint,
superior border of clavicle,
acromion, spinous
processes of C7
 Inferior - xiphoid process,
costal arch, 12th and 11th
ribs, vertebra T12
Regions
 Thoracic wall
 Thoracic cavity
Landmarks
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Jugular notch corresponds with
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The 2th thoracic vertebra in male,
the 3th thoracic vertebra in female
Sternal angle connects 2nd
costal cartilage laterally
corresponds with
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The lower border of 4th thoracic
vertebra
The bifurcation of trachea in the
adult
The beginning of aortic arch which
ends posteriorly at the same level
The esophagus is crossed by the
left main bronchus
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Xiphoid process xiphisternal junction lies
opposite the body of the 9th
thoracic vertebra
Clavicle
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Ribs and intercostal spaces
Costal arch
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Inferior fossa of clavicle
Coracoid process
Infrasternal angle
Xiphocostal angle
Papillae
Thoracic wall
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Skin
Superficial fascia
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Thoracoepigastric v.
Supraclavicular n.
Anterior and lateral
cutaneous branches of
intercostal n.
Deep fascia
Lymphatic drainage of breast
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Into pectoral ln. from lateral and
central parts of breast
Into apical and supraclavicular ln.
from superior part of breast
Into parasternal ln. from medial
part of breast
Into interpectoral ln. from deep
part of breast
The lymphatic capillaries of breast
form an anastomosing network
which is continuous across the
midline with that of the opposite
side and with that of the abdominal
wall
Internal thoracic vessels
 Internal thoracic a.&v.
 Parasternal ln.
Endothoracic fascia
The muscles of thorax
Extrinsic muscles
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Pectoralis major
Pectoralis minor
Serratus anterior
Intrinsic muscles
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Intercostales externi
Intercostales interni
Intercostales intimi
Transverses thoracis
Intercostales externi
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Origin: lower border of riⅡ)
Insertion: upper border of rib
below origin
Action: elevate ribs adding in
forced inspiration
Replaced anteriorly by external
intercostals membrane.
Intercostales interni
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Origin: upper border of rib
Insertion: lower border of rib
above origin
Action: depress ribs for forced
expiration
Replaced posteriorly by
internal intercostals membrane.
Intercostal space
Posterior intercostal v.
Posterior intercostal a.
Intercostal n.
Diaphragm
Shape and position:
dome-shaped between thorax and
abdomen, consists of a peripheral
muscular part and a central tendon
Origin
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Sternal part: xiphoid process
Costal part: lower six and costal
cartilages
Lumbar part: arises by two crura from
upper 2-3 lumbar vertebrae
Insertion: central tendon
Weak areas: triangular spaces without
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muscular tissue
Lumbocostal triangle: between
costal and lumbar parts.
Sternocostal triangle: between
costal and sternal parts.
Openings in the diaphragm
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Aortic hiatus - lies anterior to the body of the 12th thoracic
vertebra between the crura. It transmits the aorta, thoracic
duct
Esophageal hiatus - for esophagus and vagus nerves at
level of T10.
Vena cava foramen - for inferior vena cava, through central
tendon at T8 level
T8
T10
T12
Action:
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Contraction: the dome
moving downward,
increases the volume of
thoracic cavity which
results in inspiration, at
the same time the intraabdominal pressure is
increased assists in
defecation, vomiting or
child birth.
Relaxation: the dome
returns to the former
position, reduces the
volume to the thoracic
cavity, resulting in
expiration.
The Mediastinum
Concept all of organs
between the left and
right mediastinal
pleurae is called
mediastinum. It extends
from the sternum in
front to the vertebral
column behind, and
from the thoracic inlet
above to the diaphragm
below.
Subdivisions of mediastinum
Superior mediastinum
Inferior mediastinum
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Anterior mediastinum
Middle mediastinum
Posterior mediastinum
Left side of mediastnum
Left subclavian a.
Thoracic duct
Left vagus n.
Left recurrent n.
Phrenic n. &
pericardiacophrenic a.
Aortic arch
Thoracic aorta
Sympathetic trunk
Root of lung
Pericardium
Esophagus
Greater splanchnic n
Right side of mediastnum
Trachea
Left vagus n.
Arch of azygos v.
Azygos v.
Sympathetic trunk
Esophagus
Inferior vena cava
Superior vena cava
Phrenic n. &
pericardiacophrenic a.
Root of lung
Pericardium
Superior mediastinum
Locating - from inlet of
thorax to plane extending
from level of sternal angle
anteriorly to lower border of
T4 vertebra posterioly
Contents
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Superficial layer
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Thymus
Three veins
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Left brachiocephelic v.
Right brachiocephelic v.
Superior vena cava
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Middle layer
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Aotic arch and its three
branches
Phrenic n.
Vagus n.
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Posterior layer
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Trachea
Esophagus
Thoracic duct
Relations of aortic arch
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Anteriorly and to the left pleura, lung phrenic n.,
pericardiacophrenic vessels and
vagus n.
Posteriorly and to the right trachea, esophagus, left
recurrent n., thoracic duct, deep
cardiac plexus
Superiorly - its three branches,
left brachiocephalic v. and
thymus
Inferiorly - pulmonary a., arterial
ligament, left recurrent n., left
principal bronchus and superficial
cardiac plexus
Triangule of ductus arteriosus
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Bounded by phrenic n., left vagus n.
and left pulmonary a.
Contents－ arterial ligament , left
recurrent n. and superficial cardiac
plexuses
Inferior mediastinum
Anterior mediastinum
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Location - posterior to body of
sternum and attached costal
cartilages, anterior to heart and
pericardium
Contents - fat, remnants of
thymus gland, anterior
mediastinal lymph nodes
Middle mediastinum
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Location - between
anterior mediastinum and
posterior mediastinum
Contents: hart and
pericardium, beginning or
termination of great
vessels, phrenic nerves,
pericardiacophrenic
vessels , lymph nodes,
Posterior mediastinum
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Location - posterior to heart
and pericardium, anterior to
vertebrae T5 - T12
Contents: esophagus, vagus n.,
thoracic aorta, azygos system
of veins, thoracic duct, thoracic
sympathetic trunk, posterior
mediastinal lymph nodes
Relations of esophagus
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Anteriorly - trachea,
bifurcation of trachea, left
principal branchus, left
recurrent n., right pulmonary
a., anterior esophageal
plexus, pericardium, left
atrium, diaphragm
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Posteriorly - posterior
esophageal plexus,
thoracic aorta, thoracic
duct, azygos v.,
hemiazygos
v.,accessory
hemiazygos v., right
posterior intercostal v.
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Left - left common carotid a., left subclavian a., aortic arch,
thoracic aorta, superior part of thoracic duct
Right - arch of azygos v.
Relations of thoracic aorta
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Anteriorly - left root of lung,
pericardium and esophagus
Posterior - hemiazygos v.,
accessory hemiazygos v.,
Right - azygos v. and thoracic
duct
Left - mediastinal pleura
Thoracic duct
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Begins in front of L1 as a dilated sac, the
cisterna chyli, which formed by joining of
left and right lumbar trunks and intestinal
trunk
Enter thoracic cavity by passing through
the aortic hiatus of the diaphragm and
ascends along on the front of the vertebral
column, between thoracic aorta and
azygos vein
Travels upward, veering to the left at the
level of T5
At the roof of the neck, it turns laterally
and arches forwards and descends to
enter the left venous angle
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Just before termination, it receives the
left jugular, subclavian and
bronchomediastinal trunks
Drains lymph from lower limbs, pelvic
cavity, abdominal cavity, left side of
thorax, and left side of the head, neck
and left upper limb
Right lymphatic duct
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Formed by union of right jugular,
subclavian, and bronchomediastinal
trunks
Ends by entering the right venous
angle
Receives lymph from right half of head,
neck, thorax and right upper limb
Mediastinal spaces
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Retrosternal space - lies
beween sternum and
endothoracic fascia
Pretracheal space - lies within
superior mediastinum, between
trachea, bifurcation of trachea
and aortic arch
Retroesophagus space - lies
within superior mediastinum,
beween esophagus and
endothoracic fascia
Thoracic aorta
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Continuation of aortic arch at lower border of T4
Courses downward on left side of, then in front of
vertebral column
Passes through aortic hiatus of diaphragm at level
of T12 vertebra to enter abdominal cavity
Main branches
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Parietal branches
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Nine pairs posterior intercostals arteries
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One pair subcostal artery
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For lower nine intercostals spaces and
upper part of abdominal wall; superior
phrenic arteries supply the superior
surface of the diaphragm.
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Visceral branches
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Bronchial branches: one or two for each
lung
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Esophageal branches
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Pericardial branches