Practical- Orbital And Nasal Cavity Flashcards
What structure passes through the notch in the frontal bone?
The supra orbital nerve of the frontal nerve and supraorbital artery and vein
What does the supraorbital nerve apply?
Upper eyelid, forehead and skull
What does the supratrochlear nerve supply?
Upper eyelid, lower part of forehead near midline, conjunctiva
Where does the lacrimal nerve run?
Superior aspect of lateral rectus muscle
Where does the nasociliary nerve run?
It crosses the optic nerve and runs beneath the superior rectus muscle
Via what does the nasociliary nerve Carry pain and touch sensation from the cornea?
Long posterior ciliary branches
What do the posterior ethmoidal cells supply?
Mucus membranes of the paranasal sinuses and nasal cavity
What does the infratrochlear nerve supply?
Middle portion of eyelid and conjunctiva and skin of nose
Parasympathetic nerve innervation to the lacrimal gland?
Originates from the lacrimal nucleus which is part of the facial nerve nucleus in the brainstem. These fibres synapse in the SphenoPalatine ganglion.
And intraorbital tumour would cause what visual disturbance?
Double vision, bulging of the eye
What does levator palpebrae superioris do?
Lifts upper eyelid
The trochlear nerve supplies which muscle?
Superior oblique
The abducent nerve supplies which muscle?
Lateral rectus
Before entering orbit where do the ophthalmic nerve, trochlear, abducent and oculomotor pass through?
Cavernous sinus
Which direction does inferior oblique move in?
Medially and upwards
Which direction does superior oblique move in?
Medially and downwards
Oculomotor Nerve Palsy?
Down and out, because opposed by lateral rectus and superior oblique.
Drooped eyelid, dilated pupil.
What is mydriasis?
Dilated pupil, because parasympathetic fibres run on outside, so external compression will cause it before motor problems.
Which is the first cranial nerve affected by raised intracranial pressure?
Abducens nerve palsy
Blood supply to eyeball?
- Central Retinal Artery
2. Ciliary Arteries
Orbit blood supply drains into?
Superior and inferior ophthalmic veins, into superior orbital fissure into cavernous sinus.
What lies underneath the inferior concha?
Opening of nasolacrimal duct
Inferior to the middle concha is what?
Ethmoidal bulla, inferior to which is hiatus semilunaris for frontal sinus drainage
What do you find in posterior end of hiatus semilunaris?
Opening of maxillary sinus
Inside the olfactory bulb, where do olfactory nerves synapse?
With mitral cells, and the axons make olfactory tracts and divide to give lateral and medial striae.
Where do the lateral strip terminate?
In the pisiform cortex of temporal lobe
Medial stria projection?
Anterior commissure to contralateral piriform cortex
The ethmoidal and sphenoidal sinuses are innervation by what?
Posterior ethmoidal nerve of nasociliary nerve
Which nerves innervation frontal sinus?
Supratrochlear and supraorbital nerves
What do anterior and posterior nosebleeds?
Anterior- Little’s area/ kiesselbach’s plexus
Posterior- SphenoPalatine artery
