12. Innervation of the eye and adnexa.

Question 1

what type of nerve is the optic nerve ?

Answer 1

sensory nerve transmits impulse from the retina to the brain

Question 2

is the optic nerve sheathed ?

Answer 2

yes by all three meningeal layers

Question 3

from where does the oculomotor nerve enter to enter the orbit ?

Answer 3

the superior orbital fissure

Question 4

what are all the nerves which goes through the superior orbital fissure

Answer 4

occulomotor nerve
trochlear nerve
abducens nerve

Question 5

what goes through the optic canal ?

Answer 5

optic nerve and ophthalmic artery

Question 6

the ophthalmic nerve passes through what ?

Answer 6

which is in the middle cranial fossa
the lateral wall of cavernous sinus , with the maxillary inferioir - into the foramen rotundum into the ptregopalatine fossa

and superiorly the 4th trochlear nerve and 3rd cranial nerve - occulomotor nerve

abducens nerve passing through the cavity

internal carotid artery goes through cavernous sinus and goes into the top of the cavernous sinus

Question 7

the course of the ophthalmic nerve

Answer 7

when the leaves the cavernous sinus they have go into three branches and these there branches go into the superior orbital fissure
- lacrimal nerve - most lateral
frontal nerve
medial - nasocilliary nerve

lacrimal nerve enters outside the common tendinous ring
frontal nerve enters outside the common tendinous ring
nasocilliary branch goes through the common tendinous ring

trochlear nerve outside the tendinous ring

oculomotor nerve - splits into inferior and superior branch it goes outside the cavernous rings passes under and over the nasocilliary nerve into the common tendinous ring

lacrimal nerve -moves towards the lateral wall of orbit and anteriorly , but above the lateral rectus
innervating the lacrimal gland and pierces through the gland to give branches to conjunctiva and skin of superior eyelid of the lateral part
the ptergopalantine ganglion gives branches to maxillary branch of zygomaticus branch in the inferior orbital fissure
with the zygomaticus temporal branch (zygomaticus facial brach)- according foramen in the lateral wall of orbit
it then innervates the lacrimal gland- parasympathetic fibres

frontal nerve - enter superior orbital fissure - sensory innervation to superior eyelid
scalp and forhead

nasoclliary nerve connection with the sympathetic branches of the carotid plexus - one branch into ciliary ganglion
long ciliary nerve , - distributed to iris and cornea , piercing the sclera - sympathetic and sensory

posterior ethmoidal nerve - sphenoid sinus and posterior ethmoidal air cells

anterior ethmoidal nerve - middle and anterior ethmoidal air cells. The anterior ethmoidal nerve ,sends sensory fibers to the meninges, enters the nasal cavity via the nasal slit
anterior part of the nasal septum
external branch ultimately innervates skin on the lateral sides of the nose

infratrochlear nerve - skin of the upper eyelids and bridge of the nose, the conjunctiva, lacrimal sac

Question 8

the ciliary ganglion

Answer 8

gets presynaptic parasympathetic fibres from oculomotor nerve which synopsis with cell bodies of post snpatic parasympathetic neurones sends

postsynaptic sympathetic fibres from the internal carotid plexus - also goes with the short ciliary nerves

nasocilliary nerve - sensory nerve goes with the short ciliary nerves

short ciliary nerves goes above and below to the optic nerve through the optic canal and peirce the sclera

post synaptic parasympathetic fibres innervate the ciliary muscle and sphincter papillae muscle

sensory nerves fibrs - carries impulses from the iris and cornea

post synpatc sympathetic nerve fibres - innervate dilator pupillae muscle of the iris

long ciliary nerves contains - sympathetic and sensory fibres from ophthalmic and carotid plexus from the brach of nasocilliary nerves
runs into the iris -dilator papillae muscle
cornea