Mediastinum

Question 1

The mediastinum is the…

Answer 1

central compartment of the thoracic cavity.

Question 2

The mediastinum is occupied by…

Answer 2

the mass of tissue between the two pulmonary cavities.

Question 3

What covers the mediastinum on each side?

Answer 3

Mediastinal pleura

Question 4

What does the mediastinum contain?

Answer 4

All thoracic visera and structures, except lungs

Question 5

Superior boundary of mediastinum

Answer 5

Superior thoracic aperture

Question 6

What is the other name for the superior thoracic aperture?

Answer 6

Thoracic inlet

Question 7

The superior thoracic aperture is bounded by which structures (3)?

Answer 7

Manubrium, 1st pair of ribs, anterior surface of body of T1

Question 8

What is the landmark for the superior thoracic aperture?

Answer 8

Anterior sternal notch

Question 9

Mediastinoscopy

Answer 9

a surgical procedure to examine the inside of the upper chest between and in front of the lungs (mediastinum); CT scan is more preferred now

Question 10

Inferior boundary of mediastinum

Answer 10

Diaphragm, lower portion of sternum

Question 11

Anterior boundary of mediastinum

Answer 11

Sternum and costal cartilages

Question 12

Posterior boundary of mediastinum

Answer 12

Bodies of thoracic vertebrae

Question 13

Lateral boundary of mediastinum

Answer 13

Mediastinal pleura

Question 14

Major structures in mediastinum are surrounded by…

Answer 14

Blood, lymphatic vessels and nodes, nerves, and fat

Question 15

Why is the mediastinum highly mobile?

Answer 15

Because it consists primarily of hollow visceral structures united only by loose connective tissue, often infiltrated by fat.

Question 16

The mediastinum is a highly pliable and dynamic structure moved by:

Answer 16

structures within and surrounding it; the gravity and different body positions

Question 17

The ___________ of CT and _________ of the lungs and parietal pleura on its sides accommodate movement and volume and pressure changes in thoracic cavity.

Answer 17

looseness; elasticity

Question 18

Example of movement and volume and pressure changes in the thoracic cavity:

Answer 18

Respiration: movements of diaphragm, thoracic wall, and tracheobronchal tree
Circulation: contraction of heart, pulsation of arteries
Digestion: passage of food through esophagus

Question 19

What happens to the connective tissue in the mediastinum with age?

Answer 19

More fibrous and rigid = less mobile

Question 20

The mediastinum is divided into which parts?

Answer 20

superior and inferior parts

Question 21

What is the anterior boundary of the superior mediastinum?

Answer 21

Manubrium of sternum

Question 22

What is the posterior boundary of the superior mediastinum?

Answer 22

Anterior surface of the bodies of T1-T4 and corresponding IV disks

Question 23

What is the superior boundary of the superior mediastinum?

Answer 23

Superior thoracic aperture

Question 24

What is the inferior boundary of the superior mediastinum?

Answer 24

Transverse thoracic plate

Question 25

What is the transverse thoracic plate?

Answer 25

Horizontal plane from IV disc of T4-T5 to the sternal angle of Louis

Question 26

What are the contents of the superior mediastinum (A to P)?

Answer 26

• Thymus
• Great vessels: veins (left and right brachiocephalic veins and superior vena cava) and arteries (arch of aorta and its branches, right branchiocephalic trunk, left common carotid artery, left subclavian artery)
• Phrenic and vagus nerves; cardiac plexus of nerves
• Trachea and esophagus (+ left recurrent laryngeal nerve)
• Thoracic and lymphatic trunks

Question 27

What is the enlarged thyroid from the neck that sometimes goes down to the mediastinal compartments?

Answer 27

Goiter

Question 28

What is a primary lymphoid organ for development and maintenance of
the immune system?

Answer 28

Thymus