Cranial Nerves; Parasympathetics Flashcards
Describe how sympathetics reach the dilator pupilla?
By traveling in the long ciliary nerve.
Describe how sympathetics travel to the levator palpebra superioris
They travel with the oculomotor nerve
What are the symptoms of horner’s syndrome?
Occurs when sympathetics to the head and neck are compromised. Will result in ptosis, Miosis, anhydrosis and flushing of the face.
What is the function of the Edinger-Westphall nucleus?
Cranial nerve nuclei for oculomotor nerve. It supplies parasympathetics to the eye via the inferior ramus of the occulomotor nerve. The postsynaptic fibres join short ciliary nerves will run alongside the long ciliary nerves and ciliary artery, enter the eyeball and supply ciliary muscle and sphincter pupilla.
The superior ramus of the oculomotor nerve carries what?
Motor fibres from the oculomotor nucleus and sympathetics from the superior cervical ganglion to levator palpebra superiosis
Describe the light reflex
When light is shined into the eye, the signal travels via the optic nerve into the optic tract and pretectal area where is travels to the edinger-westphal nucleus bilaterally (as some of the fibres carrying the signal cross at the chiasma). The nucleus sends signals via the oculomotor nerve to the ciliary ganglion to short ciliary nerves and finally the pupillary constrictor.
What occurs if there is no PSNS input for pupil constriction
Dilated pupil
What happens if their is loss of motor innervation to levator palpebrae?
Ptosis
What occurs if their is injury to the whole occulomotor nerve
there is a loss of motor innervation to extraocular muscles except superior oblique and lateral rectus. The eye will be turned downwards and outwards
How does the nerve of pterygoid canal form?
The facial nerve gives off the greater petrosal nerve which joins the deep petrosal in foramen lacerum to form the nerve of pterygoid canal. It will supply the lacrimal gland
What other nerves supply the lacrimal gland?
Zygomatic branch of maxillary division and the lacrimal branch of opthalamic division
What is the supply of the salivary glands?
Parasympathetic secretomotor supply to submandibular and sublingual glands are in chorda tympani which will unify with the lingual branch of mandibular nerve of trigeminal before synapsing at the submandibular ganglion. (PSNS comes from chorda tympani but then travels in the lingual nerve as the chorda tympani joins the lingual nerve)
Describe the nerve supply of the parotid gland
Parasymapthetics from glossopharyngeal nerve travel in tympanic nerve, branch of glossopharyngeal nerve, to the middle ear. From the ear the fibres travel in the lesser petrosal nerve and synapses at the otic ganglion where the auriculotemporal nerve arises and goes on to supply the parotid gland.
