GI and Neurology of Thorax

Question 1

What are the regions of the esophagus?

Answer 1

cervical part
thoracic part (btw T1 and esophageal Hiatus of diaphragm)
abdominal part

Question 2

What/where are the constrictions of the esophagus? (4)

Answer 2

at the cricopharyngeus M.
at the aortic arch
at the left bronchus
at the esophageal hiatus of the thoracic diaphragm

Question 3

What cranial nerve is the vagus N?

What type of nerve is it?

Answer 3

CNX

parasympathetic

Question 4

What artery does the vagus N initially run with?

Answer 4

common corotid A

Question 5

What are the main branches of the vagus N in the thorax? (6)

Answer 5

Left recurrent laryngeal N
pulmonary branches
cardiac branches (3)
esophageal branches
anterior vagal trunk (from L vagus n)
posterior vagal trunk (from r vagus N)

Question 6

What spinal rami make up the phrenic N?

Answer 6

anterior rami of C3-C5

C3 to 5 keep the diaphragm alive

Question 7

What do you do to remember where the anterior and posterior vagal trunks arise from?

Answer 7

put hands on steering wheel –> turn right
left vagus N –> anterior vagal trunk
R vagus N –> posterior vagal trunk

Question 8

What is the difference btw the right and left recurrent laryngeal Ns?

Answer 8

right arises much earlier in the neck

left arises in the thorax and loops under aortic arch and ligamentum arteriosum to return to larynx

Question 9

What two structures do the right and left phrenic Ns run between?

Answer 9

mediastinal parietal pleura and fibrous pericardium

Question 10

What spinal nerves to the intercostal nerves arise from?

Answer 10

1st-11th thoracic anterior rami

Question 11

If you found a typical intercostal nerve btw ribs, where would you find it?

Answer 11

on the inferior edge of the superior rib

btw internal and innermost intercostal Ms

Question 12

What are the typical intercostal Ns?

Answer 12

3rd-6th

Question 13

What are the rami communicates?

Answer 13

connect intercostal N to thoracic sympathetic trunk

Question 14

What are the typical branches of intercostal Ns?

Answer 14

rami communicates
collateral branches
lateral cutaneous branches –> anterior and posterior branches
muscular branches

Question 15

What anterior cutaneous branches or the intercostal Ns supply the breast?

Answer 15

T4-T6

Question 16

What makes the 1st intercostal N atypical?

Answer 16

no cutaneous branches and majority of superior portion joins the brachial plexus

Question 17

What makes the 2nd intercostal N atypical?

Answer 17

small part joins w/ brachial plexus

lateral cutaneous branch supplies skin of axilla = intercostobrachial N

Question 18

What is the intercostobrachial N?

Answer 18

cutaneous N of the axilla that arises from the 2nd intercostal N

Question 19

What makes intercostal Ns 7-11 atypical?

Answer 19

begin as intercostal, but as the go anteriorly, turn into thoracic abdominal Ns

Question 20

What does the sympathetic NS control?

what is its distribution?

Answer 20

“fight or flight”
distribution is widespread
controls sweat (all other glandular secretions are parasympathetic)

Question 21

What is the parasympathetic NS distribution like?

Answer 21

limited

Head, neck and trunk viscera, never in body wall or extremities

Question 22

What NS branch controls glandular secretion?

Answer 22

parasympathetic

except sweat = sympathetic

Question 23

What stimulates vasoconstriction?

Answer 23

sympathetic NS
(except coronary As)

Question 24

What spinal levels involve sympathetic division?

Answer 24

T1-L2

Question 25

Where are the cell bodies of presynaptic sympathetic Ns? | Where do they travel?

Answer 25

lateral horn of spinal cord --> anterior root to anterior ramus --> paravertebral ganglia

Question 26

What are the 3 synaptic options for sympathetic preganglionic neurons?

Answer 26

1. can enter paravertebral ganglion --> synapse to postsynaptic neuron on same level 2. Can enter paravertebral ganglion --> ascend or descend to synapse on diff spinal level 3. Can enter paravertebral ganglion and exit w/out synapsing and go on thru splanchnic N to postsynaptic neuron in PREvertebral ganglion

Question 27

What are the pre and post synaptic neurons like in the sympathetic NS?

Answer 27

``` pre = short post = long ```

Question 28

What makes up the sympathetic trunks?

Answer 28

paravertebral ganglia linked vertically

Question 29

What are the 4 prevertebral ganglion you should know?

Answer 29

celiac ganglion superior mesenteric ganglion aorticorenal ganglion inferior mesenteric ganglion

Question 30

What characterizes the cardiac splanchnic N?

Answer 30

presynaptic cell bodies in lateral horn of T1-5 or 6 --> synapse onto postsynaptic bodies in cervical and thoracic sympathetic trunk --> pulmonary plexus

Question 31

What characterizes the pulmonary splanchnic N?

Answer 31

preynaptic Cell bodies in lateral horn of T2-3 --> synapse in thoracic sympathetic trunk --> fibers to pulmonary plexus

Question 32

What are the 3 abdominopelvic splanchnic Ns and what do they generally do?

Answer 32

greater splanchnic N Lesser splanchnic N Least splanchnic N travel from sympathetic trunk --> prevertebral ganglia in abdomen

Question 33

What characterizes the greater splanchnic N?

Answer 33

T5-9 or 10 --> fibers to esophageal plexus and celiac ganglion

Question 34

What characterizes the lesser splanchnic N?

Answer 34

T10-11 --> fibers to celiac and superior mesenteric ganglion --> superior mesenteric plexus

Question 35

What characterizes the least splanchnic N?

Answer 35

T12 --> aorticorenal ganglion

Question 36

What cranial Ns and spinal levels make up the parasympathetic NS?

Answer 36

CN 3, 7, 9, and 10 | S2-4

Question 37

What are the pre and post-synaptic neurons like in the parasympathetic NS?

Answer 37

``` pre = long post = short ```

Question 38

Where are the postsynaptic parasympathetic cell bodies located?

Answer 38

in the walls of target organs

Question 39

What makes up the pulmonary plexus? | Is it sympathetic or parasympathetic?

Answer 39

mixed sympathethic from pulmonary splanchnic Ns parasympathetic from pulmonary branches of vagus N innervates Lungs, bronchi, and pleurae

Question 40

What makes up the cardiac plexus? | Is it sympathetic or parasympathetic?

Answer 40

``` mixed sympathetic = cardiac splanchnic Ns parasympathetic: superior, middle, and inferior cardiac branches of vagus N fibers near sinuatrial and AV nodes superficial and deep ```

Question 41

What makes up the aortic plexus? | Is it sympathetic or parasympathetic?

Answer 41

mixed continuous superiorly w/ superficial cardiac plexus continues inferiorly as aortic plexus in abdomen

Question 42

Where is the superficial cardiac plexus located?

Answer 42

covers anterior surface of heart

Question 43

Where is the deep cardiac plexus located?

Answer 43

anterior to bifurcation of the trachea, posterior to aortic arch, superior to bifurcation of pulmonary trunk

Question 44

What makes up the esophageal plexus? | Is it sympathetic or parasympathetic?

Answer 44

mixed sympathetic: greater splanchnic N and aortic plexus parasympathetic: esophageal branches of Vagus N