Nerves of the thorax Flashcards
Which tissues are supplied by sympathetics only?
- Certain blood vessels
- erector pili muscles
- sweat glands
What neuron is myelinated?
The preganglionic neuron
What neuron is unmyelinated?
The postganglionic neuron
Where does the vagus nerve exit the cranial cavity?
The jugular foramen
Where does the vagus nerve lie when descending down the neck?
Between the internal jugular vein and the internal (then common) carotid artery
What vessels does the right vagus nerve lie between when entering the thoracic cavity?
The right subclavian artery and the brachiocephalic vein
What vessels does the left vagus nerve lie between when entering the thoracic cavity?
Posterior to the left brachiocephalic vein, between the subclavian and common carotid arteries.
What nerve does the (left and right) recurrent laryngeal nerve come off of?
The Vagus nerve (left and right)
What vessel does the right recurrent laryngeal nerve wind around?
The right subclavian artery (then ascends towards the larynx)
What vessel does the left recurrent laryngeal nerve wind around?
The aortic arch (just posterolateral to the ligamentum arteriosum)
What do the recurrent laryngeal nerves innervate?
- Intrinsic laryngeal muscles (except 1)
- Middle and inferior pharyngeal constrictor muscles
- Sensory to the laryngeal cavity below the level of the vocal folds
What levels are the lateral horns located in on the spinal cord
T1 -L2
Where is the sympathetic trunk located?
- Anterior to the neck of the ribs (lateral aspect of vertebral bodies)
- Covered by the parietal pleura
- Extends from the atlas to the cocyx
What is the name of the ganglion adjacent to the C1 - 4 vertebra?
Superior Cervical Ganglion
What is the name of the region where the left and right sympathetic trunks fuse?
The ganglion impar
At what levels is the superior cervical sympathetic ganglia found?
C1 - 4
At what levels is the middle cervical sympathetic ganglia found?
C5 - 6
At what levels is the inferior cervical sympathetic ganglia found?
C7 - 8
What is the name of the inferior cervical + T1 ganglia called?
Stellate ganglion (cervicothoracic)
What colour are unmyelinated axons?
Grey
What colour are myelinated axons?
White
What are the sympathetic nerves called that supply the abdominal viscera?
Splanchnic nerves
What are the thoracic splanchnic nerves called?
- Greater splanchnic nerve
- Lesser splanchnic nerve
- Least splanchnic nerve
What are the splanchnic nerves called?
- Thoracic splanchnic nerve (greater, lesser, least)
- Lumbar splanchnic nerve
- Pelvic splanchnic nerve
What vertebrae do the sympathetics of the head come from?
T1- T3
What vertebrae do the sympathetics of the upper limb come from?
T4 - T6
What vertebrae do the sympathetics of the thoracic and abdominal walls come from?
T1 - T-12
What vertebrae do the sympathetics of the lower limb come from?
T12 - L2
What are the visceral plexuses called in the thorax?
- Cardiac plexus
- Pulmonary plexus
- Oesophageal plexus
Where is the cardiac plexus located?
Anterior to the bifurication of the trachea and posterior to the descending aorta
Where is the pulmonary plexus located?
Anterior and (mainly) posterior to the roots of the lungs
What nerves are contained in the cardiac plexus?
- Sympathetics from T1 - 5 ganglia + inferior and middle cervical ganglia
- Parasympathetics from vagus
What nerves are contained in the pulmonary plexus?
- Sympathetics from T2 - 4 ganglia
- Parasympathetics from vagus
Where do intercostal nerves originate from?
Anterior rami of thoracic spinal nerves
What is contained within the intercostal nerves?
- Motor branches to the intercostal and abdominal wall muscles
- Visceromotor branches to vessels
- Lateral cutaneous branch
- Anterior cutaneous branch
What kind of tumour can affect the sympathetic trunk or stellate ganglia?
- Pancoast’s tumour
Tumour at the apex of the lung
What is Horner’s syndrome
- often a result of pancoast’s tumour
- Results in:
- Ptosis (drooping) of the upper eyelid
- Pupillary constriction (miosis)
- Anhydrosis (lack of sweating)
- Flushing of the face
The nerves of what vertebra lead into the gretaer spanchnic nerve?
T5 - 9
The nerves of what vertebra lead into the lesser spanchnic nerve?
T10 - 11
The nerves of what vertebra lead into the least spanchnic nerve?
T12
