Phrenic, Vagus, Sympathetic Trunks and Ganglia Flashcards
which cranial nerve is the vagus nerve?
10
what sort of nerve fibres are carried by the vagus nerve?
parasympathetic fibres to thoracic and abdominal viscera
where does the vagus nerve originate from?
medulla oblongata in the brain stem
which blood vessel does the vagus nerve follow out of the skull?
the internal jugular vein
which structure in the neck does the vagus nerve pass into?
carotid sheath
in-between internal jugular vein and internal common carotid artery
how does the vagus nerve enter the thoracic inlet?
lies in between the venous and arterial planes
posterior to brachiocephalic vein
medial to phrenic nerves
at what vertebral level does the vagus nerve leave the thorax? With what structure?
- T10
- oesophagus
how does the vagus nerve pass the root/hilum of the lung?
posteriorly
how does the R vagus relate to the trachea?
lies lateral
how does the R vagus relate to the arch of the azygous vein?
medial to the arch
what vessels form plexus at the oesophagus?
L and R vagus nerves
which nerve passes on the left side of the aortic arch?
L vagus
which arteries is the L vagus related to?
L common carotid, L subclavian
the recurrent laryngeal nerves are branches of which nerves?
vagus nerves
what autonomic plexuses do both the vagus nerves give preganglionic branches to ?
pulmonary
cardiac
oesophageal
what are the sensory and motor innervations of the recurrent laryngeal nerves?
motor to laryngeal muscles
sensory to mucosa below the vocal folds
which nerve curves superiorly under the Right subclavian artery?
right recurrent laryngeal
what vessel does the left recurrent laryngeal nerve pass under?
arch of the aorta
which nerve passes posterior to the ligamentum arteriosum?
L recurrent laryngeal
what structures does the L RCLN pass between to reach the larynx?
trachea and oesophagus in a groove
which arteries do the RCLNs relate to?
inferior thyroid arteries
what surgery hurts the RCLNs and the inferior thyroid arteries at risk? what is the outcome if damaged?
- thyroid surgery
- hoarse voice if damaged
a tumour where causes hoarseness of voice?
in left lung
enlarged lymph nodes due to tumour compresses the L RCLN
what are the functional units of the nervous system?
neurones specialised for rapid communication
what is the sympathetic neurotransmitter?
noradrenaline
what is the parasympathetic neurotransmitter?
acetylcholine
what are the functions of the sympathetic system on cardiovascular system?
increases BP increases heart rate+contraction strength dilates coronary vessels increases respiratory efficiency constricts peripheral circulation inhibits sphincters controls body temperature
where do preganglionic bodies of the sympathetic system lie?
lateral grey matter of thoracic spinal cord
which vertebral levels do primary neurones of preganglionic cell bodies of the sympathetic nervous system arise from?
T1 to L2
how is sympathetic outflow described?
thoracolumbar
what lies in sympathetic ganglion?
postganglionic cell bodies
in what 2 ways are postganglionic cell bodies of sympathetic system distributed?
- hitch hike along somatic nerves/ and or arteries and are distributed widely all over the body
- supply adjacent viscera through autonomic plexuses
what forms the sympathetic trunks?
2 trunks
formed of 2 chains of cell bodies of postganglionic neurones
lie alongside all the vertebral bodies atlas to coccyx
what are the lengths of sympathetic pre and post ganglionic neurones?
short pre
long post
how do sympathetic preganglionic neurones reach the sympathetic trunk?
white rami communicates
they either: synapse immediately in adjacent ganglion
or travel up or down in trunk to be distributed above and below T1 and L2
what is the name of the structure where the sympathetic ganglion fuse?
ganglion impart opposite coccyx
what cervical ganglia are there?
superior, middle and inferior
what is the stellate ganglion? where is it?
fusion of middle and inferior cervical ganglia
lies on neck of rib 1
what pre ganglionic neurones pass straight through trunk to reach abdominal viscera and adrenal gland?
greater: T5-9, coeliac
lesser: T10, 11, superior mesenteric
least splanchnic nerves: T12, inferior mesenteric
what are the three things primary neurones can do when they reach body wall and limbs?
- synapse immediately and secondary neurones pass in GRC to spinal nerve
- travel up trunk synapse with cervical ganglion above T1, 2y neurones pass in GRC to cervical spinal nerves
- travel down trunk and synapse in a ganglion below L2, 2y neurones pass in GRC to lumbar and sacral spinal nerves
what levels does head receive sympathetic innervation from?
T1-T3
what level of sympathetic nerves supplies upper limb?
T4-T6
what level are the abdominal and thoracic walls sympathetic neurones derived from?
T1-12
what is the level of sympathetic innervation to lower limb?
T12- L2
where are parasympathetic nerves distributed to?
head
neck
viscera
what preganglioinc cell bodies lie in the CNS?
parasympathetic
where do pregnaglionic cell bodies of parasympathetic system lie?
cranial= 3,7,9 and 10 sacral= 2,3 ,4
how is parasympathetic outflow described?
craniosacral
Where do postganglionic parasympathetic cell bodies lie?
special ganglia of the head and neck
close to viscera they supply
contribute to anatomical plexuses
what are the effects of the parasympathetic system?
slows breathing and heart rate reduces CO and BP opens sphincters meiosis-constriction of pupils secretomotor to glands
heart and lungs are supplied by neurones arising between which vertebral levels?
T1-5
what do cardiac branches (2y sympathetic neurones)supply?
SA node
coronary vessels
T1 fibres included
where do primary neurones travel to and synapse to provide cardiac branches?
ascend trunk and synapse in T1 and inferior and middle cervical ganglia (stellate)
where do cardiac branches (2y sympathetic neurones) emerge from?
cervical part of sympathetic trunk
pass down to the cardiac plexus at the tracheal bifurcation
pulmonary sympathetic fibres emerge from which level?
T2-4
bronchial dilation and bronchial vessels
what level do oesophageal sympathetic fibres emerge form?
T4-6
neurones originating from T7-9 supply what?
stomach
where is a Pancots tumour located?
apex of lung
what causes Horners syndrome?
Pancots tumour
what does pants tumour affect?
sympathetic trunk
stellate ganglion on neck of 1st rib
what is the neurological effect of pants tumour?
compromises sympathetic supply to head and neck on the same side as tumour
what are the signs and symptoms of horners syndrome?
Ptosis- upper eyelid dropping
mitosis= pupillary constriction
anhydrosis= lack of sweating
flushing of face