Orbit 2 Flashcards
Name 2 sensory nerves to the eyeball
- Optic
2. Ophthalmic of trigeminal
Name 3 sensory nerves to the eyeball
- Oculomotor
- Trochlear
- Abducent
What are the 3 branches of the ophthalmic nerve?
- Frontal
- Lacrimal
- Nasociliary
What are the 2 terminal branches of the frontal nerve?
- Supratrochlear
2. Supraorbital
Where do the supratrochlear and supraorbital nerves innervate?
Sensory innervation for skin of forehead and scalp
Where does the lacrimal nerve innervate?
Lacrimal gland
Once innervating the lacrimal gland, what happens to the lacrimal nerve?
Pierces orbital septum and supplies the skin of lateral part of the eyelid
Where does the nasociliary nerve innervate?
Anterior nasal mucosa
Describe the path of the nasociliary nerve
- Gives off sensory branches
- Passes through anterior ethmoidal foramen
- Enters nasal cavity
What branch is given off the nasociliary nerve?
External nasal
Where does the external nasal nerve supply?
Skin of the nose
Where does the optic nerve enter the orbit?
Optic canal
What nerve accompanies the optic nerve in the optic canal?
Ophthalmic of trigeminal
What surrounds the optic nerve?
Meninges
Describe the course of the optic nerve within the optic canal
- Runs within the cone of recti muscles
2. Pierces sclera as a point medial to posterior pole of eyeball
What occurs when the optic nerve pierces the sclera?
The meninges and sclera fuse
What is the function of the optic nerve?
Transmits sensory information regarding brightness, red-green colour perception and visual field
What is papilledema?
Oedema of the optic disc
What is papilledema a sign of?
Elevated intracranial pressure
List 3 things which can cause papilledema
- Brain tumour
- Cerebral haemorrhage
- Cavernous sinus thrombosis
What are 2 symptoms of papilledema?
- Blurred vision
2. Double vision
Where does the oculomotor nerve leave the brainstem?
Between the midbrain and pons