ANATOMT OF SVC & AZYGOS SYSTEM AND APPLIED ASPECTSppt

this presentation will give detailed knowledge about superior vena cava and azygos venous system and clinical impoetance also.this topic consist of origin,course,relation and applied aspects of SVC AND AZYGOS VENOUS SYSTEM

1. SUPERIOR VENA CAVA &
AZYGOS VENOUS SYSTEM
Dr .M.Vasanthakohila
Post graduate
Department ofAnatomy
Govt Kilpauk medical college
AN 23.3 , Date : 5.03.2024
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4. GREAT VESSEL OF THORACIC
CAVITY
•Contains great vessels such as
superior vena cava, aorta, and
pulmonary trunk.
•Bring blood toward heart from
body and lungs and circulate
blood from heart –various
body parts and lungs
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5. SUPERIOR VENA CAVA
Q. Write short note on superior vena cava
•Large vein collects blood from upper half
of body and drains –into right atrium
•Dimension: Length: 7 cm, Width: 1.25 cm
•Location: Lies in superior and middle
mediastinum
Formation
•Formed by union of right and left
brachiocephalic or innominate veins –
lower border of right first costal cartilage
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6. SUPERIOR VENA CAVA
Course
–Descends vertically downward behind 1
st
and 2
nd
intercostal spaces
–Pierces pericardium –level of 2
nd
costal
cartilage
–Thus lower half of superior vena cava
lies within pericardium
Termination
–Opens (terminates) into upper part of
right atrium behind 3
rd
right costal
cartilage
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7. SUPERIOR VENA
CAVA
Relations
•Upper half of SVC lies in
superior mediastinum,
whereas its lower half lies in
middle mediastinum within
fibrous pericardium
•Relations of SVC are –follows
Anterior
–Chest wall (1
st
and 2
nd
intercostal spaces, 2
nd
and 3
rd
costal cartilages)
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8. SUPERIOR VENA
CAVA
Relations
Anterior
–Anterior margin of right lung
and pleura
–Lower half, SVC –covered by
pericardium
–Right internal thoracic
vessels
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9. SUPERIOR VENA CAVA
Relations
Posterior
•Trachea and right vagus nerve
(posteromedial)
•Right lung and pleura
(posterolateral)
•Right pulmonary hilum
(posterior –lower half of SVC)
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10. SUPERIOR VENA CAVA
Relations
•Right lateral relations
–Right phrenic nerve
–Right pleura and lung
•Left lateral relations
–Ascending aorta
–Brachiocephalic trunk
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11. SUPERIOR VENA CAVA
Tributaries
•Formative tributaries: Right and
left brachiocephalic veins
•Azygos vein: Arches over root of
right lung and opens into SVC –
level of right 2
nd
costal cartilage
•Mediastinal and pericardial
veins: These are several small
veins drain into SVC
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14. Clinical
Integration
Obstruction of superior vena cava
•Because of cancer of lungs or enlargement
of mediastinal lymph node, SVC may get
compressed/obstructed
•Signs and symptoms depend on site of
SVC compression
•Can be grouped as
–SVC compression above opening
of azygos vein
•This case, venous blood from upper
half of body return to right atrium
through azygos vein
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15. Clinical
Integration
Obstruction of superior vena
cava
•Can be grouped as
–SVC compression below
opening of azygos vein
•This case, venous blood from
upper half of body return –
right atrium through inferior
vena cava, via.
thoracoepigastricveins
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16. •Note: Azygos vein opens in SVC just before SVC pierces
pericardium
•Patients of SVC obstruction may complain of facial swelling,
chest pain, cough, dysphagia, and so on
•These patients have distention of veins of neck and chest
wall, facial edema and upper limb edema, and dilated veins –
chest wall
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19. BRACHIOCEPHALIC
VEINS
Q. Write short note on brachiocephalic
veins
There –two brachiocephalic veins, right and left
Formation
–Each brachiocephalic vein –formed by
union of corresponding internal jugular and
subclavian veins
–Termination: Both (right and left)
brachiocephalic veins unite –form superior
vena cava
–Extent: Each brachiocephalic vein extend
from corresponding sternoclavicular joint –
lower border of first right costal cartilage
where they form SVC
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20. BRACHIOCEPHALIC VEINS
Tributaries
•Formative tributaries:
–Internal jugular vein
–Subclavian vein
•Vertebral vein
•Inferior thyroid vein
•Internal thoracic vein
•First posterior intercostal vein
•Left superior intercostal vein (only
and left)
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22. AZYGOS
VEIN
Q. Write short note on azygos vein
Q. List tributaries of azygos vein
•Present only on right in
thoracic cavity
Functions of Azygos Vein
•Drains blood from thoracic wall
and upper part of lumbar
region
•Connects superior and inferior
vena cava
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23. AZYGOS
VEIN
•Azygos venous system
includes straight veins lie –
paravertebral position,
such as azygos,
hemiazygos, and
accessory hemiazygos
veins
•Veins –not accompanied
by arteries (azygos =
unpaired in Greek)
•Veins drain back, thoracic
and abdominal walls
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24. AZYGOS
VEIN
Origin
•Formed by union of right
ascending lumbar vein and
right subcostal vein
•Sometimes, May arise from
posterior aspect of IVC or as
continuation of right
subcostal veins
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25. AZYGOS
VEIN
Termination
•Opens in SVC just before
entry of SVC in pericardium
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26. AZYGOS
VEINCourse
•Ascends upward and enters
thoracic cavity through aortic
opening of diaphragm (level-
T12 vertebra)
•Ascends upward in posterior
mediastinum up to T4 vertebra
•At T4 vertebra, arches over
of right lung and opens into
superior vena cava (just before
entry of SVC in pericardium)
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27. Relations
•Anterior
–Esophagus
•Posterior
–Lower eight thoracic vertebrae
–Right posterior intercostal arteries
•To right
–Right lung and pleura
–Greater splanchnic nerve
•To left
–Thoracic duct
–Descending thoracic aorta in lowerpart
–Esophagus, trachea, and right vagus nerve in upper part
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AZYGOS
VEIN

28. AZYGOS
VEIN
Tributaries
•Right superior intercostal
vein
•5
th
to 11
th
right posterior
intercostal veins
•Accessory hemiazygos
vein
•Hemiazygos vein
•Right bronchial vein
•Esophagealveins
•Mediastinal veins
•Pericardial veins
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29. Clinical
Integration
Collateral channel in vena cava obstruction
–In obstruction of SVC, blood –directed to IVC
through collateral circulation by azygos vein
Rupture of azygos vein
–Traumatic or surgical rupture of azygos vein may
result in hemothorax
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33. HEMIAZYGOS
VEIN
•Also called inferior
hemiazygos vein
•Mirror image of lower part of
azygos vein
Formation
–Formed by union of left
ascending lumbar vein
and left subcostal vein
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34. HEMIAZYGOS
VEIN
Course
•Enters posterior mediastinum by
piercing left crus of diaphragm
•Ascends upward up to T8
vertebra, where it turns to right
and crosses vertebral column
anteriorly
Termination
•Opens in azygos vein –level of
T8 vertebra
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35. HEMIAZYGOS
VEIN
Tributaries
•Formative tributaries:
Left ascending lumbar
vein, left subcostal vein
•Lower three (9
th
–11
th
)
left posterior intercostal
veins
•Some esophageal and
mediastinal veins
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36. ACCESSORY HEMIAZYGOS
VEIN
•Also called superior
hemiazygos vein
•Mirror image of upper
part of azygos vein
Formation
•Begins as
continuation of left
fourth posterior
intercostal vein
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37. ACCESSORY HEMIAZYGOS
VEIN
Course
•Begins at medial end of
fourth intercostal space
and descends downward
on left of vertebral column
•At level of 8
th
thoracic
vertebra, it turns to right
and crosses vertebral
column
Termination
•Opens in azygos vein at
level of T8 vertebra
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38. ACCESSORY HEMIAZYGOS
VEIN
Tributaries
•Formative tributary
left 5
th
posterior
intercostal vein
•Left 5
th
to 8
th
posterior intercostal
vein
•Left bronchial vein
(occasionally)
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39. Thank you………….
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