Mediastinum

Question 1

anterior boundary of the mediastinum

Answer 1

sternum, costal cartilages

Question 2

posterior boundary of the mediastinum

Answer 2

thoracic vertebral bodies

Question 3

lateral boundaries of the mediastinum

Answer 3

mediastinal pleura

Question 4

location of superior mediastinum

Answer 4

posterior to manubrium of the sternum, and anterior to the first 4 thoracic vertebrae

Question 5

structures in the superior mediastinum from anterior to posterior

Answer 5

1. thymus
2. right and left brachiocephalic veins
3. superior vena cava
4. arch of the aorta and its branches (brachiocephalic trunks, common carotid, subclavian)
5. trachea and esophagus
6. phrenic and vagus nerves
7. left recurrent laryngeal nerve
8. thoracic duct

Question 6

label superior mediastinum

Answer 6

Question 7

location of thymus

Answer 7

most anterior compartment in superior mediastinum, directly anterior to the right and left brachiocephalic veins (that come off the superior vena cava)

Question 8

characteristic of thymus

Answer 8

large in children, atrophy after puberty, is a thymic remnant in elderly

Question 9

function of thymus

Answer 9

was involved in the early development of the immune system

Question 10

what forms the brachiocephalic veins

Answer 10

formed by the union of the internal jugular and subclavian veins before the left brachiocephalic vein crosses midline to join with the right brachiocephalic vein to form superior vena cava

Question 11

label aortic arch and branches

Answer 11

Question 12

location of esophagus

Answer 12

posterior to trachea, but anterior to thoracic vertebrae in superior mediastinum, connects pharynx and stomach

Question 13

innervation of esophagus

Answer 13

the vagus nerves form esophageal plexus

Question 14

branches of vagal nerves

Answer 14

left and right vagal nerves come together to form esophageal plexus, then the fibers reform to make anterior vagal trunk and posterior vagal trunk around the esophagus

Question 15

contribution of anterior and posterior vagal trunks

Answer 15

left vagal nerve becomes the anterior vagal trunk and the right vagal nerve becomes the posteiror vagal trunk

Question 16

contribution of phrenic nerve

Answer 16

C3,C4,C5

Question 17

location of phrenic nerve

Answer 17

passes anterior to lung roots between mediastinal pleura and pericardium

Question 18

what does the phrenic nerve innervate

Answer 18

motor and sensory diaphragm, sensory innervation to mediastinal pleura, fibrous pericardium, parietal pericardium

Question 19

innervation of vagus nerves

Answer 19

parasymphathetic innervation to thoracic and abdominal viscera, branches superiorly to the left and right recurrent laryngeal nerves

Question 20

location of vagus nerves

Answer 20

pass posterior to lung roots

Question 21

location of left recurrent laryngeal nerve

Answer 21

passes inferior to arch of aorta, then ascends in a groove between the trachea and esophagus

Question 22

location of right recurrent laryngeal nerve

Answer 22

branches at the split of the brachiocephalic trunk into the right common carotid and the right subclavian artery

Question 23

that is the function of the thoracic duct

Answer 23

is the principal channel through which lymph from most of the body is returned to the venous system

Question 24

location of thoracic duct

Answer 24

posterior to esophagus in between aorta and azygos vein, it enters the inferior portion of the superior mediastinum to the left venous angle to empty into the junction of the left subclavian and left internal jugular veins

Question 25

location of the anterior inferior mediastinum

Answer 25

posterior to the body of the sternum and anterior to pericardial sac

Question 26

anterior mediastinum contains

Answer 26

portion of thymus and internal thoracic blood vessels

Question 27

location of middle mediastinum

Answer 27

centrally located, in thoracic cavity

Question 28

contents of middle mediastinum

Answer 28

pericardium, heart, origins of great vessels and various nerves

Question 29

location of posterior mediastinum

Answer 29

posterior to pericardial sac, anterior to vertebral bodies of mid and lower thoracic vertebrae

Question 30

structures in posterior mediastinum

Answer 30

1. esophagus and its associated nerve plexus
2. thoracic aorta and its branches
3. azygos system
4. thoracic duct
5. sympathetic trunks
6. thoracic splanchnic nerves