12 - Autonomics of the Head and Neck Flashcards
What are some responses in the head of the neck that are due to parasympathetics and sympathetics?
Where in the spinal cord do the parasympathetics and sympathetics arise from?
Fill in the following table relating to the sympathetic innervation of the head and neck.
- Sympathetic plexus on ECA is sweat glands, rest is ICA, especially following the opthalmic artery
- Top 3 ganglia in the sympathetic chain are cervical ganglion
- If synapsing at T1-L2 the sympathetics hitchhike on spinal nerves not blood vessels
What is Horner’s syndrome and what does it indicate?
Pathology in the lung apex or common carotid artery as there is unopposed parasympathetics due to a pathology impinging on the sympathetics
e.g Pancoast’s tumour, CCA aneurysm or dissection
When would you a partial ptosis and when would you have a full ptosis?
Partial: loss of sympathetic innervation to superior tarsal muscle
Full: CNIII lesion so loss of skeletal part of levator palpebrae superioris
Which cranial nerves carry parasympathetics from the brainstem?
III, VII, IX and X
At what spinal levels are the cervical ganglion?
How do parasympathetics get from their origin in the brain stem to their target tissues?
Run with cranial nerves not blood vessels like the sympathetics
What are the names of the following in the parasympathetic system of the head and neck:
- Nuclei
- Cranial nerves
- Autonomic ganglion
- Target tissues
How do the parasympathetics that hitchhike with CN III reach their target tissue?
- Ciliary is the ganglion associate with oculomotor nerve
- Remember parasympathetics lay on outside of nerve so they are affect first in raised ICP
Describe the pupillary light reflex and why if you shine light into one eye, both pupils constrict in response.
How do the parasympathetics that hitchhike with CN VII reach their target tissue?
- Hitchhike with greater petrosal and chorda tympani nerve
- Pterygopalatine and Submandibular ganglion
- Post ganglionics run with trigeminal lingual nerve
How would you figure out where a lesion in the facial nerve is?
- Ask about dry eyes, dry mouth, facial expression
- If parasympathetics spared then must be after it has left stylomastoid foramen
How do the parasympathetics that hitchhike with CN IX reach their target tissue?
- Jugular foramen along the tympanic nerve which is sensory to the middle ear
- Then parasympathetics join lesser petrosal nerve and go to otic ganglion in infratemporal fossa
- Hitchhikes onto auricotemporal Vc after ganglion to parotid gland
How do the parasympathetics that hitchhike with CN X reach their target tissue?
What target tissue are associated with the four named parasympathetic ganglia?
What do the middle and superior cervical ganglia go on to innervate?
- Hyperthyroidism
- Raised thyroid increases the sensitivity of sympathetics so overstimulation of sympathetics has lead to increased activity of the superior tarsal muscle
- Exophthalmus only associated with Grave’s
What has happened to the ventricles and why are the patient’s pupils dilated?
- There has been midline shift due to increased ICP
- Increased ICP is pushing on parasympathetics sitting on periphery of oculomotor nerve damaging it
- Need to do a craniotomy
