Lecture 11: Thoracic Neurology

Question 1

What are the four constriction points (where food get stuck) in the esophagus?

Answer 1

1) Cricopharyngeus Muscle
2) Arch of aorta
3) Left main bronchus
4) Esophageal Hiatus

Question 2

Is the vagus nerve sympathetic or parasympathetic when it comes to structures in the thorax?

Answer 2

Parasympathetic

Question 3

How do left and right recurrent laryngeal nerves differ?

Answer 3

Right comes of Vagus nerve in the neck below the subclavian A.
Left comes of Vagus nerve in the thorax and loops around arch of aorta

Question 4

The Right Vagus Nerve becomes the _____ vagal trunk.

Answer 4

Posterior vagal trunk

Question 5

The Left Vagus Nerve becomes the _____ vagal trunk.

Answer 5

Anterior vagal trunk

Question 6

Where is the phrenic nerve (C3-5) found in the thorax?

Answer 6

Between mediastinal parietal pleura and fibrous pericardium

Question 7

What is an intercostal nerve?

What is the subcostal nerve?

Answer 7

Anterior ramus of thoracic spinal nerve
-travels along inferior edge of rib

Anterior ramus of T12. Nerve is below the rib of T12

Question 8

What are atypical intercostal nerves?

Why are they atypical?

Answer 8

Nerves 1-2,: 1 is part of the brachial plexus, 2’s lateral cutaneous branch is the intercostobrachial nerve which supplies axilla skin

Nerves 7-11: become thoracoabdominal nerves as they have no ribs to rest on anteriorly and are in the abdomen area

Question 9

What are typical intercostal nerves?

Answer 9

Nerves 3-6

Question 10

How do intercostal nerves communicate with the thoracic sympathetic trunk?

Answer 10

Via rami communicantes

Question 11

Where are presynaptic cells of the sympathetic nervous system found?

Answer 11

Lateral horn of spinal cord in the thoracolumbar region

Question 12

What is the pathway of sympathetic synaptic innervation to viscera in the thorax (heart)?

Answer 12

Lateral horn > anterior root > anterior rami > white ramus communicantes > synapse on paravertebral ganglion on same or another level > cardiopulmonary splanchnic nerves > heart

Question 13

What is the pathway of sympathetic synaptic innervation to viscera in the abdomen?

Answer 13

Lateral horn > anterior root > anterior rami > white ramus communicans > leave thoracolumbar sympathetic trunk > prevertebral ganglion near the target organ and synapse there > travel via abdominopelvic (greater, lesser, least) splanchnic nerves > synapse to target organ

Question 14

How does sympathetic (parietal) synaptic innervation to smooth muscles, skin, and sweat glands in the thorax

Answer 14

Lateral horn > anterior root > anterior rami > white ramus communicantes > gray ramus communicantes on the anterior rami > thoracic sweat glands and smooth muscle

Question 15

Where does the Superior and Middle Cardiac Branches come off the Vagus N.?

How about the Inferior Cardiac Branch?

Answer 15

Neck

Thorax

Question 16

What are the types of the abdominosplanchnic nerves?

Answer 16

Greater, lesser and least

Question 17

Where do the parasympathetic presynaptic cell bodies reside?

What are the parasympathetic presynaptic fibers?

Where do the parasympathetic postsynaptic cell bodies reside?

Answer 17

Craniosacral region (brainstem and sacral spinal cord)

4 cranial nerves and pelvic splanchnic nerves

cranial ganglia in the target organ

Question 18

Where does the sympathetic and parasympathetic branches of the pulmonary plexus come from?

Answer 18

Sympathetic: Pulmonary splanchnic Ns.

Parasympathetic: Pulmonary branches of Vagus N.

Question 19

Where does the sympathetic and parasympathetic branches of the cardiac plexus come from?

Answer 19

Sympathetic: Cardiac Splanchnic Nerves

Parasympathetic: Superior, Middle and Inferior branches of the Cardiac branches of Vagus N.

Question 20

Where does the sympathetic and parasympathetic branches of the aortic plexus come from?

Answer 20

Both are continuous with the superficial cardiac plexus.

Question 21

Where does the sympathetic and parasympathetic branches of the esophageal plexus come from?

Answer 21

Sympathetic: Greater splanchnic nerve

Parasympathetic: Esophageal branch of the Vagus N.