Thorax Mediastinum Question And Answers

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Mediastinum Question And Answers

Question 1. What are the boundaries of mediastinum and how is it divided?
Answer:

Boundaries of Mediastinum

  • It lies between two lungs
  • Boundaries
    • Anteriorly: Sternum
    • Posteriorly: Thoracic vertebral column (T1–T12)
    • Superiorly: Thoracic inlet
    • Inferiorly: Diaphragm
    • Laterally: Mediastinal pleura
  • Mediastinum is divided into:
    • Superior mediastinum
    • Inferior mediastinum

By a transverse plane passing through the sternal angle and the intervertebral disc between T4 and T5.

Mediastinum Subdivisions Of Mediastinum

Question 2. Write a note on superior mediastinum and what are its contents.
Answer:

Superior Mediastinum Boundaries:

  • Anteriorly: Manubrium part of sternum
  • Posteriorly: T1-T4 vertebrae and intervertebral discs between them
  • Superiorly: Thoracic inlet
  • Inferiorly: Transverse plane passing through the sternal angle and the intervertebral disc between T4 and T5

Mediastinum Transverse Section Through The Superior Madiastinum Just Above The Summit Of The Ach Of The Arota To Show Some Relations Of The Trachea

Superior Mediastinum Contents

  • Phrenic nerve
  • Vagus nerve
  • Thoracic duct
  • Left recurrent laryngeal nerve
  • Brachiocephalic veins
  • Aortic arch and its 3 branches (Brachiocephalic artery, left common carotid artery, left Subclavian artery)
  • Mnemonic: PVT Left BAttle
  • Muscles: Sternothyroid, sternohyoid
  • Other veins left superior intercostal vein, superior vena cava (upper part)
  • Trachea and esophagus
  • Thmus.

Read And Learn More: Anatomy Question And Answers 

Question 3. Write a note on inferior mediastinum and what are its divisions and contents.
Answer:

Inferior Mediastinum Boundaries:

  • Anteriorly: Body of sternum
  • Posteriorly: T5-T12 vertebrae and intervertebral discs between them
  • Superiorly: Transverse plane passing through the sternal angle and the intervertebral disc between T4 and T5
  • Inferiorly: Diaphragm (superior surface)
  • Laterally (on both sides): Mediastinal pleura.

The inferior mediastinum is further subdivided into:

  • Anterior mediastinum
  • Middle mediastinum
  • Posterior mediastinum.
  • By the Pericardial sac.

Anterior Mediastinum Boundaries:

  • Anteriorly: Body of sternum
  • Posteriorly: Pericardium
  • Laterally (on both sides) : Mediastinal pleura
  • Superiorly: Transverse plane passing through the sternal angle and the intervertebral disc between T4 and T5
  • Inferiorly: Diaphragm (superior surface).

Anterior Mediastinum Contents:

  • Mediastinal branches of internal thoracic artery
  • Sternopericardial ligaments
  • Lymphatics and lymph nodes
  • Thus.

Mediastinum Lateral View Of Thoracic Cavity Showing Few Contents

Middle Mediastinum Boundaries:

  • Anteriorly: Sternopericardial ligaments
  • Posteriorly: Azygos vein, descending aorta,
  • Esophagus
  • Laterally (on both sides): Mediastinal pleura
  • Superiorly: Transverse plane passing through the sternal angle and the intervertebral disc between T4 and T5
  • Inferiorly: Diaphragm (superior surface).

Middle Mediastinum Contents

  • Pericardium and the heart
  • Arteries: Ascending aorta, pulmonary trunk and pulmonary arteries
  • Veins: Superior vena cava, azygos vein, pulmonary veins
  • Nerves: Deep cardiac plexus and phrenic nerve
  • Tracheobronchial lymph nodes
  • Bifurcation of trachea and principal bronchi.

Posterior Mediastinum Boundaries:

  • Anteriorly
  • Pericardium
  • Pulmonary vessels
  • Bifurcation of trachea
  • Posteriorly: T5–T12 vertebrae and the intervertebral discs between them
  • Laterally (on both sides): Mediastinal pleura
  • Superiorly: Transverse plane passing through the sternal angle and the intervertebral disc between T4 and T5
  • Inferiorly: Diaphragm (superior surface).

Posterior Mediastinum Contents:

  • Arteries: Descending thoracic aorta and its branches
  • Veins: Azygos, hemiazygos, and accessory hemiazygos veins
  • Nerves: Vagus nerve, splanchnic nerve
  • Posterior mediastinal lymph nodes
  • Esophagus
  • Thoracic duct.

Mnemonic: Posterior mediastinum structures. There are four birds:

  1. The esophagus (esophagus)
  2. The vaGOOSE nerve
  3. The azyGOOSE vein
  4. The thoracic DUCK (duct).

Mediastinum Multiple Choice Question

Question 1. The contents of the anterior mediastinum in an adult are all except:

  1. Thymus gland
  2. Phrenic nerve
  3. Branches of internal thoracic artery
  4. Areolar tissue

Answer: 1. Thymus gland

Question 2. The posterior mediastinum has the following except:

  1. Esophagus
  2. Thoracic duct
  3. Inferior vena cava
  4. Right descending thoracic aorta

Answer: 4. Right descending thoracic aorta

Question 3. Which of the following structures is/are located entirely within the mediastinum?

  1. Thoracic duct
  2. Phrenic nerves
  3. Pericardial sac
  4. Vagus nerves

Answer: 3. Pericardial sac

Question 4. A tumor growing in the posterior mediastinum could directly affect which of the following structures?

  1. Azygos vein
  2. Superior vena cava
  3. Aortic arch
  4. Right atrium of the heart

Answer:

Question 5. The thymus is located in:

  1. Posterior mediastinum
  2. Anterior mediastinum
  3. Middle mediastinum
  4. Superior mediastinum

Answer: 2. Anterior mediastinum

 

 

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