Mediastinum Anatomy Quiz: Test Your Knowledge of Thoracic Cavity

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Questions and Answers

Which vein receives the right sup intercostal vein?

Hemiazygos vein

Accessory hemiazygos vein

Azygos vein (correct)

Thoracic duct

Which structure lies posterior to the root of the left lung, pericardium, and esophagus?

Esophageal plexus

Azygos vein

Thoracic aorta (correct)

Thoracic duct

What is the result if the IVC is blocked?

Venous blood drains into the SVC through the azygos vein and hemiazygos vein (correct)

Venous blood drains into the SVC through the hemiazygos vein

Venous blood drains into the aorta

Venous blood does not drain at all

Which vein is formed by the union of the left ascending lumbar vein and left subcostal vein?

Hemiazygos vein Signup and view all the answers

Where does the thoracic duct lie?

Posterior mediastinum Signup and view all the answers

What is the name of the lowest ganglion of the sympathetic trunk?

Ganglion impar Signup and view all the answers

Which structure bifurcates in the superior mediastinum?

trachea Signup and view all the answers

Which vein forms the Superior Vena Cava?

union of right and left brachiocephalic veins Signup and view all the answers

Which nerve crosses the left side of the arch of aorta?

left vagus nerve Signup and view all the answers

Which structure is located in the neck and anterior part of the superior mediastinum?

thymus Signup and view all the answers

Which vein rises above the superior border of the manubrium in infants and children?

left brachiocephalic vein Signup and view all the answers

Which nerve descends in a posterior direction towards the trachea?

right vagus nerve Signup and view all the answers

Which structure is NOT found in the Anterior Mediastinum?

Trachea Signup and view all the answers

Which nerve is found in the Superior Mediastinum?

Left recurrent nerve Signup and view all the answers

Which structure is palpable in the jugular notch?

trachea Signup and view all the answers

Which vein is formed by the union of internal jugular and subclavian veins?

right brachiocephalic vein Signup and view all the answers

What is the name of the vein that is found in the Middle Mediastinum?

Azygos vein Signup and view all the answers

Which structure is found in the Posterior Mediastinum?

Thoracic duct Signup and view all the answers

Which nerve enters the superior mediastinum between the right brachiocephalic vein and brachiocephalic trunk?

right vagus nerve Signup and view all the answers

What is the name of the ganglia where the greater splanchnic nerve synapses?

5th-9th thoracic ganglia Signup and view all the answers

Which structure connects the pulmonary trunk to the arch of aorta?

ductus arteriosus Signup and view all the answers

Which structure is shared by the Superior and Middle Mediastinum?

Superior Vena Cava Signup and view all the answers

Study Notes

Cardiac Plexus

Located in the middle mediastinum
Formed by the bifurcation of the trachea

Great Vessels in the Middle Mediastinum

Thoracic aorta
Thoracic duct
Posterior mediastinal lymph nodes
Azygos, hemiazygos, and accessory hemiazygos veins
Esophagus
Esophageal plexus
Thoracic sympathetic trunks
Thoracic splanchnic nerves

Thoracic Aorta

Lies posterior to the root of the left lung and pericardium
Changes its name at the T12 level
Gives rise to:
- Left two bronchial arteries
- Posterior intercostal arteries (3-11)
- Superior phrenic artery
- Esophageal artery
- Mediastinal artery
- Subcostal artery

Thoracic Duct

Largest lymphatic channel
Located in the posterior mediastinum and superior mediastinum
Receives lymph from the esophagus, pericardium, and diaphragm

Posterior Mediastinal Lymph Nodes

Located posterior to the pericardium
Receives lymph from the esophagus, pericardium, and diaphragm

Azygos System of Veins

Azygos vein: formed by the union of the ascending lumbar vein and subcostal vein
Right crus of the diaphragm
Level of T4 venous arch anteriorly
Receives:
- Right superior intercostal vein
- Right posterior intercostal veins
- Hemiazygos vein
- Right bronchial vein
Opens into the superior vena cava

Hemiazygos Vein

Formed by the union of the left ascending lumbar vein and left subcostal vein
Left crus of the diaphragm
Receives:
- Inferior three posterior intercostal veins (9-11)
- Inferior esophageal vein
- Mediastinal veins
Level of T9
Opens into the azygos vein

Accessory Hemiazygos Vein

Receives:
- Posterior intercostal veins (4-8)
- Left bronchial vein
Opens into the azygos vein at the level of T7

Clinical Importance

If the IVC is blocked, venous blood drains into the SVC through the azygos vein and hemiazygos vein

Sympathetic Trunk

Extends from the base of the skull to the coccyx
Has 22-23 ganglia
Composed of longitudinal and transverse fibers
Unites with the opposite side at the ganglion impar

Preganglionic Fibers

First way: terminate at their corresponding ganglia
Second way: enter the sympathetic trunk without making a synapse at their corresponding ganglia

Mediastinum

Organization of Mediastinum

Central part of the thoracic cavity
Covered by mediastinal pleura
Contains thoracic viscera

Clinical Importance of Sternal Angle

Bifurcation of the trachea
Azygos vein → SVC
Ascending aorta → arch of aorta → descending aorta
2nd rib joins with the sternum
Transverse plane between the superior and inferior mediastinum

Superior Mediastinum

Posterior to the manubrium and anterior to the first four thoracic vertebrae
Superior border: superior thoracic aperture
Inferior border: transverse thoracic plane (sternal angle and IV disc of T4 and T5)
Laterally: mediastinal pleura

Contents of Superior Mediastinum

Thymus
Right and left brachiocephalic veins
Left superior intercostal vein
Superior vena cava
Arch of aorta with its three large branches
Trachea
Esophagus
Phrenic nerves
Vagus nerves
Left recurrent laryngeal nerve
Thoracic duct
Other small vessels and nerves

Thymus

Lymphoid organ
Located in the neck, anterior part of the superior mediastinum, and inferior mediastinum
Plays an important role in the development of the immune system
Diminishes at puberty

Right and Left Brachiocephalic Veins

Formed by the union of internal jugular and subclavian veins posterior to the medial end of the clavicle
Left vein crosses the midline
Union of the two veins forms the SVC posterior to the lower border of the right first costal cartilage

Superior Vena Cava

Terminates at the lower margin of the right third costal cartilage
Receives:
- Azygos vein
- Pericardial and mediastinal veins
SVC and IVC are oriented along the same vertical axis

Arch of Aorta and its Branches

Aorta has three parts: arch, ascending, and descending
Ascending aorta emerges from the heart and forms the arch of aorta
From right to left:
- Brachiocephalic trunk
- Left common carotid
- Left subclavian

Ligamentum Arteriosum

In the superior mediastinum
Fetal circulation: ductus arteriosus
Connects the pulmonary trunk to the arch of aorta and permits the blood to bypass the lungs during development

Trachea and Esophagus

Trachea is the midline structure that is palpable in the jugular notch
Posteriorly: esophagus
Crossed by the azygos vein on the right side and arch of aorta on the left side
Bifurcation of trachea, whereas esophagus continues

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Description

Test your knowledge of the mediastinum, a central part of the thoracic cavity, including its organization, clinical importance, and anatomical features. Take this quiz to learn more about the mediastinum and its components.

Mediastinum Anatomy Quiz

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