Thorax 9 - Vagus Nerves - Autonomics

Question 1

Which structure do the vagus nerves leave the thorax with and therefore at what vertebral level do they pass through the diaphragm?

Answer 1

Oesophagus @ level of T10

Question 2

Name the 3 autonomic plexuses that the vagus nerve pre-ganglionic branches give rise to.

Answer 2

Pulmonary
Cardiac
Oesophageal

Question 3

What type of nerve is at risk during thyroid surgery?

Answer 3

Recurrent laryngeal

Question 4

What can damage to the recurrent laryngeal nerve cause?

Answer 4

Hoarse voice

Question 5

List some other causes of hoarse voice.

Answer 5

Lung tumour

Enlarged lymph nodes

Question 6

What does the parasympathetic nervous system supply and not supply?

Answer 6

Head, neck & viscera

Skin & limbs

Question 7

Where is the parasympathetic ganglion located?

Answer 7

Distant to the cell body, out in the far periphery

Question 8

Where is the sympathetic ganglion located?

Answer 8

Close to the CNS, short primary neurone, long secondary neurone

Question 9

Where do the preganglionic sympathetic cell bodies lie in the CNS?

Answer 9

Lateral grey matter of the thoracic spinal cord b/n T1 & L2 - Thoracocolumbar Outflow

Question 10

Where does the sympathetic trunk lie?

Answer 10

Between the atlas and the coccyx

Question 11

How does each spinal nerve join onto the postganglionic neurone?

Answer 11

Grey ramus communicantes

Question 12

What is the spinal level of sympathetic innervation of the upper limb?

Answer 12

T4 to T6

Question 13

What is the spinal level of sympathetic innervation of the head?

Answer 13

T1 to T3

Question 14

What is the spinal level of autonomic innervation of the stomach?

Answer 14

T7 to T9

Question 15

What is the spinal level of autonomic innervation of the oesophagus?

Answer 15

T4 to T6

Question 16

What is the spinal level of autonomic innervation of the bronchi and bronchioles?

Answer 16

T2 to T4

Question 17

What is the spinal level of autonomic innervation of the SA node and coronary vessels?

Answer 17

T1

Question 18

Where do the vagus nerves originate?

Answer 18

Cranial Nerve X & Medulla Oblongata

Question 19

What type of fibres do the vagus nerves contain and to where do they transmit them?

Answer 19

Sympathetic fibres to the thoracic and abdominal viscera

Question 20

Describe the course the vagus nerve takes in passing out of the head region.

Answer 20

From medulla oblongata, passes out of the skull with the internal jugular vein. Then passes through the carotid sheath between the internal jugular vein and the common carotid artery.

Question 21

Where do the vagus nerves lie in relation to the BCV’s and the phrenics?

Answer 21

Posterior to BCV’s

Medial to phrenics

Question 22

Where does the right vagus nerve lie in relation to the trachea?

Answer 22

Lateral

Question 23

Where does the right vagus nerve lie in relation to the arch of the azygos vein?

Answer 23

Medial

Question 24

Where does the right vagus nerve lie in relation to the lung hilum?

Answer 24

Posterior

Question 25

Which side of the aortic arch does the left vagus nerve pass?

Answer 25

Left

Question 26

What do the vagus nerves give rise to?

Answer 26

Recurrent laryngeal nerves

Question 27

What do a. sensory and b. motor branches of the recurrent laryngeal nerves supply?

Answer 27

a. mucosa between vocal folds

b. laryngeal muscles

Question 28

The right recurrent laryngeal nerve curves superiorly underneath a certain structure. What is this structure?

Answer 28

Right subclavian artery

Question 29

Describe the course the left recurrent laryngeal nerve follows past the arch of aorta, ligamentum arteriosum, trachea and oesophagus.

Answer 29

Passes under the arch of aorta and posterior to the ligamentum arteriosum, passing superiorly in a groove between the trachea and oesophagus to reach the larynx

Question 30

Why are the right and left recurrent laryngeal nerves in different places on opposite sides of the body?

Answer 30

Because of the persistence of the ductus arteriosus, the left RL nerve has to hook around the 6th arch, rather than the 4th which the right RL nerve hooks around