Posterior Mediastinum

Question 1

What seperates the inferior and superior mediastinum?

Answer 1

Line- connects sternal angle anteriorly- T4/5 junction posteriorly

Question 2

Where does the trachea bifurcate?

Answer 2

T4/5

Question 3

What does the posterior mediastinum contain?

Answer 3

Descending aorta
Azygos veins
Oesophagus
Thoracic duct
Splanchnic and intercostal nerves

Question 4

What structures does the descending aorta give rise to?

Answer 4

Posterior intercostal arteries- supply intercostal
Bronchial arteries- supply lung
Oesophagal
Pericardial
Phrenic- supply diaphragm

Question 5

What level does the aorta pass through diaphragm?

Answer 5

T12

Question 6

What level does the azygos veins arise

Answer 6

L1/L2- abdomen
Drain blood from posterior thoracic and returns superior vena cava

Question 7

What does azygos system contain?

Answer 7

Azygos vein right side
Shorter hemiazygos vein left side

Question 8

What is it called where trachea bifurcates?

Answer 8

Carina

Question 9

Innervation of oesophagus?

Answer 9

Descending aorta- oesophageal arteries

Question 10

What level does the oesophagus pass through the diaphragm?

Answer 10

T10- oesophageal hiatus

Question 11

Function thoracic duct?

Answer 11

Return lymph to venous system

Question 12

What structure gives rise to the thoracic duct?

Answer 12

Cisterna chyli

Question 13

What is a ganglion?

Answer 13

Collection of bodies outside CNS

Question 14

What level are cell bodies of preganglionic sympathetic neurons?

Answer 14

Thoracic and upper lumbar spinal segments
T1-L2/3

Question 15

Path of fibres

Answer 15

Exit in spinal nerves T1-L2/3
Enter sympathetic trunk via communicating branch

Question 16

3 things preganglionic axon does after in sympathetic trunk?

Answer 16

1) Synapse in ganglion at lvl of entry
2) Ascends or descends in trunk and synapses in ganglion
3) Travel through ganglion without synapsing

Question 17

What does this show?

Answer 17

Synapse in ganglion at its lvl of entry

Question 18

What does this show?

Answer 18

Ascend or descend in trunk before synapsing in ganglion

Question 19

What does this show?

Answer 19

Travels through ganglion (and trunk), no synapse

Question 20

What lvl are the splanchnic nerves at?

Answer 20

Greater splanchnic nerve- T5-9
Lesser splanchnic nerve- T10-11
Least splanchnic nerve- T12
Lumbar splanchnic nerves- L1-L2

Question 21

Where are the greater, lesser and least splanchnic nerves formed? Innervation?

Answer 21

Formed posterior mediastinum- enter abdomen
Synapse with second neuron
Innervate abdominal viscera

Question 22

What does the posterior intercostal space contain?

Answer 22

● Intercostal muscles
● Posterior intercostal artery
● Posterior intercostal vein- drains to azygos
● Posterior intercostal nerve

Question 23

How is the thoracic viscera innervated?

Answer 23

Sympathetic- cardiopulmonary
Parasympathetic- vagus

Question 24

What do the para and sympathetic fibres form?

Answer 24

Autonomic plexuses

Question 25

What innervates:
SAN heart
Bronchi
Oesophagus

Answer 25

SAN heart- cardiac plexus
- symp- increase HR and force
contraction
- para- decrease HR and force
contraction
Bronchi- pulmonary plexus
- symp- relax
- para- constrict
Oesophagus- oesophageal plexus
- symp- inhibit peristalsis
- para- stimulate peristalsis

Question 26

Function of visceral afferents?

Answer 26

Relay sensroy info from thoracic viscera to CNS
Via vagus and splanchnic nerves

Question 27

What type of pain when feel it in different area to where issue is?

Answer 27

Referred pain

Question 28

What level will cardiac pain present?

Answer 28

T1-T5

Question 29

What cord segments innervate skin neck and shoulder?

Answer 29

C3-5