GI and Neurology of Thorax Flashcards
What are the regions of the esophagus?
cervical part thoracic part (btw T1 and esophageal Hiatus of diaphragm) abdominal part
What/where are the constrictions of the esophagus? (4)
at the cricopharyngeus M.
at the aortic arch
at the left bronchus
at the esophageal hiatus of the thoracic diaphragm
What cranial nerve is the vagus N?
What type of nerve is it?
CNX
parasympathetic
What artery does the vagus N initially run with?
common corotid A
What are the main branches of the vagus N in the thorax? (6)
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)
What spinal rami make up the phrenic N?
anterior rami of C3-C5
C3 to 5 keep the diaphragm alive
What do you do to remember where the anterior and posterior vagal trunks arise from?
put hands on steering wheel –> turn right
left vagus N –> anterior vagal trunk
R vagus N –> posterior vagal trunk
What is the difference btw the right and left recurrent laryngeal Ns?
right arises much earlier in the neck
left arises in the thorax and loops under aortic arch and ligamentum arteriosum to return to larynx
What two structures do the right and left phrenic Ns run between?
mediastinal parietal pleura and fibrous pericardium
What spinal nerves to the intercostal nerves arise from?
1st-11th thoracic anterior rami
If you found a typical intercostal nerve btw ribs, where would you find it?
on the inferior edge of the superior rib
btw internal and innermost intercostal Ms
What are the typical intercostal Ns?
3rd-6th
What are the rami communicates?
connect intercostal N to thoracic sympathetic trunk
What are the typical branches of intercostal Ns?
rami communicates
collateral branches
lateral cutaneous branches –> anterior and posterior branches
muscular branches
What anterior cutaneous branches or the intercostal Ns supply the breast?
T4-T6
What makes the 1st intercostal N atypical?
no cutaneous branches and majority of superior portion joins the brachial plexus
What makes the 2nd intercostal N atypical?
small part joins w/ brachial plexus
lateral cutaneous branch supplies skin of axilla = intercostobrachial N
What is the intercostobrachial N?
cutaneous N of the axilla that arises from the 2nd intercostal N
What makes intercostal Ns 7-11 atypical?
begin as intercostal, but as the go anteriorly, turn into thoracic abdominal Ns
What does the sympathetic NS control?
what is its distribution?
“fight or flight”
distribution is widespread
controls sweat (all other glandular secretions are parasympathetic)
What is the parasympathetic NS distribution like?
limited
Head, neck and trunk viscera, never in body wall or extremities
What NS branch controls glandular secretion?
parasympathetic
except sweat = sympathetic
What stimulates vasoconstriction?
sympathetic NS (except coronary As)
What spinal levels involve sympathetic division?
T1-L2
Where are the cell bodies of presynaptic sympathetic Ns?
Where do they travel?
lateral horn of spinal cord –> anterior root to anterior ramus –> paravertebral ganglia
What are the 3 synaptic options for sympathetic preganglionic neurons?
- can enter paravertebral ganglion –> synapse to postsynaptic neuron on same level
- Can enter paravertebral ganglion –> ascend or descend to synapse on diff spinal level
- Can enter paravertebral ganglion and exit w/out synapsing and go on thru splanchnic N to postsynaptic neuron in PREvertebral ganglion
What are the pre and post synaptic neurons like in the sympathetic NS?
pre = short post = long
What makes up the sympathetic trunks?
paravertebral ganglia linked vertically
What are the 4 prevertebral ganglion you should know?
celiac ganglion
superior mesenteric ganglion
aorticorenal ganglion
inferior mesenteric ganglion
What characterizes the cardiac splanchnic N?
presynaptic cell bodies in lateral horn of T1-5 or 6 –> synapse onto postsynaptic bodies in cervical and thoracic sympathetic trunk –> pulmonary plexus
What characterizes the pulmonary splanchnic N?
preynaptic Cell bodies in lateral horn of T2-3 –> synapse in thoracic sympathetic trunk –> fibers to pulmonary plexus
What are the 3 abdominopelvic splanchnic Ns and what do they generally do?
greater splanchnic N
Lesser splanchnic N
Least splanchnic N
travel from sympathetic trunk –> prevertebral ganglia in abdomen
What characterizes the greater splanchnic N?
T5-9 or 10 –> fibers to esophageal plexus and celiac ganglion
What characterizes the lesser splanchnic N?
T10-11 –> fibers to celiac and superior mesenteric ganglion –> superior mesenteric plexus
What characterizes the least splanchnic N?
T12 –> aorticorenal ganglion
What cranial Ns and spinal levels make up the parasympathetic NS?
CN 3, 7, 9, and 10
S2-4
What are the pre and post-synaptic neurons like in the parasympathetic NS?
pre = long post = short
Where are the postsynaptic parasympathetic cell bodies located?
in the walls of target organs
What makes up the pulmonary plexus?
Is it sympathetic or parasympathetic?
mixed
sympathethic from pulmonary splanchnic Ns
parasympathetic from pulmonary branches of vagus N
innervates Lungs, bronchi, and pleurae
What makes up the cardiac plexus?
Is it sympathetic or parasympathetic?
mixed sympathetic = cardiac splanchnic Ns parasympathetic: superior, middle, and inferior cardiac branches of vagus N fibers near sinuatrial and AV nodes superficial and deep
What makes up the aortic plexus?
Is it sympathetic or parasympathetic?
mixed
continuous superiorly w/ superficial cardiac plexus
continues inferiorly as aortic plexus in abdomen
Where is the superficial cardiac plexus located?
covers anterior surface of heart
Where is the deep cardiac plexus located?
anterior to bifurcation of the trachea, posterior to aortic arch, superior to bifurcation of pulmonary trunk
What makes up the esophageal plexus?
Is it sympathetic or parasympathetic?
mixed
sympathetic: greater splanchnic N and aortic plexus
parasympathetic: esophageal branches of Vagus N
