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Flashcards in Mediastinum Deck (34):
1

Mediastinum Definition

space btw the two pleural sacs
contains all structures of thorax except for lungs and pleura

2

Superior Border

Thoracic Inlet

3

Inferior Border

Diaphragm

4

Anterior Border

Sternum and Costal Cartilages

5

Posterior Border

Thoracic Vertebrae

6

Division

Superior - all above sternal angle
Inferior - all below sternal angle

7

Inferior is divided into...

Anterior
Middle
Posterior

8

Superior Division Borders

Superior to sternal angle
Level of T4-T5

9

Structures in Superior Division

Thymus
Brachiocephalic Veins
SVC
Aortic arch and branches
Vagus
Left recurrent laryngeal nerve
Phrenic
Trachea
Thoracic Duct
Esophagus
Sympathetic Chain

10

Thymus

Superior mediastinum
Infancy and chilhood is posterior to manubrium
Adulthood it is mainly adipose tissue, only 10% is functioning

11

Brachiocephalic Veins

Superior Mediastinum
Form from union of internal jugular veins with subclavian
Left is twice as long as right

12

Branches from Aortic Arch

superior mediastinum
Brachiocephalic artery
Left CC
Left Subclavian

13

Inferior mediastinum Border

Inferior to sternal angle
T4-T5 through T12 vertebrae

14

Anterior Mediastinum Borders

Anteriorly = sternum and transversus thoracis
Posteriorly = pericardium

15

Anterior Mediastinum Structures

Remains of thymus
Loose CT
Fat
Lymph nodes
Vessels
Branches of internal thoracic artery
Sternopericardial ligament

16

Middle Mediastinal Borders

Anteriorly - body of sternum, 2nd-6th costal cartilages
Posteriorly - 5th-8th thoracic vertebrae

17

Middle Mediastinal Structures

Heart
Pericardium
Phrenic
Primary bronchi
Origins of great vessels
Nerves
Lymphatics

18

What are the great vessels in middle mediastinum

Superior and Inferior Vena Cava
Ascending Aorta
Pulmonary Arteries and Veins

19

Lymphatics - Middle Mediastinum

Subepicardial lymph nodes
Lymph vessels - join to form single vessel
Drain into inferior tracheobronchial lymph nodes

20

Posterior Mediastinum Borders

Anteriorly - pericardium and diaphragm
Posteriorly - T5 to T12 vertebrae

21

Posterior Mediastinum Structures

Thoracic Aorta
Thoracic Duct
Azygos System
Esophagus
Nerves
Lymphatics

22

Thoracic Aorta Branches - Posterior

Bronchial - 1 R, 2L
Esophageal - usually 2 branches
Mediastinal - to lymph nodes and other tissues
Pericardial - to pericardium
Posterior intercostals - 3rd - 11th spaces
Subcostal - under 12 rib
Superior phrenic - last branch, superior surface of diaphragm

23

Thoracic Duct - Posterior

Cisterna chyli - expanded end of duct at 12th vertebrae
Passes through aortic hiatus
Duck btw two gooses (esophagus and azygos)
Ascends on right side, crosses over btw T4-T6
Empties into union of left internal jugular vein and left subclavian vein

24

Azygos system - Posterior

Connects inferior cava to superior vena cava

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Azygos Vein - P

Drains right side of thoracic and abdominal wall
Union of right subcostal and right ascending lumbar vein
Ascends posterior thoracic wall within post mediastinum
Arches over root of right lung into SVC

26

Hemiazygos Vein - P

Union of left subcostal and left ascending lumbar vein
Drains left 9th-11th IC spaces
Ascends to cross over to azygos at T9

27

Accessory Hemiazygos Vein - P

Descends the left side of thoracic vertebral column
Drains left 4th-8th IC spaces
Crosses over to azygos at T7 or T8

28

Right and Left Superior Intercostal Veins - P

Right - drains into Azygos
Left - drains into left brachiocephalic vein

29

Esophagus - P

Aortic Constriction
Bronchial Constriction
Diaphragmatic Constriction

30

Nerves - P

Esophageal Plexus - Vagus
Aortic Plexus - Autonomic Nerves
Thoracic Splanchnic Nerves - Greater, Lesser, Least

31

Greater Splanchnic - P

Via sympathetic chain ganglia T5-T9

32

Lesser Splanchnic - P

Via sympathetic chain ganglia T10 - T11

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Least Splanchnic - P

Via sympathetic chain ganglia T12

34

Lymphatics - P

Posterior mediastinal lymph nodes
Intercostal lymph nodes
Diaphragmatic lymph nodes